Control device, imaging device, control method, and program

Abstract

To provide a control device, an imaging device, a control method, and a program that can suppress abrupt changes in brightness between multiple frames obtained by imaging using the imaging device due to switching of the transmittance of an electronic neutral density filter.SOLUTION: A control device includes a processor that acquires multiple split exposures determined on the basis of a change time required for the transmittance of an electronic neutral density filter mounted on the imaging device to change from a first transmittance to a second transmittance that can achieve a target exposure for the imaging device and the target exposure, and performs control to apply the multiple split exposures to exposures of multiple frames obtained by capturing images with the imaging device at least within the change time.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a control device, an imaging device, a control method, and a program. [Background technology]

[0002] Patent Document 1 discloses an imaging device in which exposure conditions are set based on the characteristics of a transmittance control element. The imaging device described in Patent Document 1 includes a processor. In the imaging device described in Patent Document 1, the processor calculates a first exposure condition range based on photometry of the imaging device, and if the first exposure condition range is not included in a second exposure condition range to which the control range acquired by the transmittance control element can be applied, changes the exposure conditions of the imaging device so that the calculated first exposure condition range is included in the second exposure condition range.

[0003] Patent Document 2 discloses an imaging device having an element for controlling the amount of light transmission and a light receiving element for receiving light transmitted through the element for controlling the amount of light transmission. The imaging device described in Patent Document 2 has a calculation unit for estimating the time required for the bleaching process of the element for controlling the amount of light transmission, and if the bleaching time estimated by the calculation unit exceeds a threshold, the sensitivity of the light receiving element is increased.

[0004] Patent Document 3 discloses an exposure control method for an imaging device that includes a photographing lens having an aperture, a solid-state imaging element, multiple exposure adjustment means, a means for determining the brightness of a subject, and an exposure control means for controlling the multiple exposure adjustment means in accordance with the brightness of the subject to obtain a target exposure value.

[0005] In the imaging device described in Patent Document 3, the multiple exposure adjustment means include a first exposure adjustment means that adjusts the exposure amount by making an ND filter appear and disappear in the aperture opening, and a second exposure adjustment means consisting of at least one of an exposure adjustment means that adjusts the exposure amount by adjusting the opening area of ​​the aperture opening, an exposure adjustment means that adjusts the exposure amount by adjusting the electronic shutter speed of the solid-state imaging element, and an exposure adjustment means that controls the exposure amount by controlling the amplifier gain of the image signal obtained from the solid-state imaging element.

[0006] The exposure control method for an imaging device described in Patent Document 3 controls the first exposure adjustment means so that, when the brightness of the subject is below a predetermined level, the first exposure adjustment means is maintained in an ND filter fully open state in which the ND filter is not applied to the aperture at all, and, when the brightness of the subject is equal to or higher than the predetermined level, the first exposure adjustment means is maintained in an ND filter fully closed state in which the ND filter is applied to the entire aperture.Furthermore, the exposure control method for an imaging device described in Patent Document 3 controls the second exposure adjustment means so that, when the first exposure adjustment means causes a state transition between the ND filter fully open state and the ND filter fully closed state, the second exposure adjustment means generates an exposure change amount that offsets the exposure change amount accompanying the state transition of the first exposure adjustment means. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2023-121787 [Patent Document 2] Japanese Patent Application Publication No. 2020-034590 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-045648 Summary of the Invention

[0008] One embodiment of the present disclosure provides a control device, an imaging device, a control method, and a program that can suppress a sudden change in brightness between multiple frames obtained by imaging using an imaging device due to switching of the transmittance of an electronic neutral density filter. [Means for solving the problem]

[0009] A first aspect of the present disclosure is a control device that includes a processor, which obtains multiple split exposures determined based on a change time required for the transmittance of an electronic neutral density filter mounted on an imaging device to change from a first transmittance to a second transmittance that can achieve a target exposure of the imaging device and the target exposure, and controls the application of the multiple split exposures to exposures of multiple frames obtained by imaging by the imaging device at least within the change time.

[0010] A second aspect of the present disclosure is a control device according to the first aspect, in which a plurality of frames are obtained by capturing images based on a default frame rate, the number of the plurality of frames is determined based on the change time and the default frame rate, and the plurality of split exposures are determined based on a target exposure and the number of frames.

[0011] A third aspect of the present disclosure is a control device according to the first or second aspect, in which, when the change time exceeds a first threshold, the split exposure in the process of changing from a first transmittance to a second transmittance among the multiple split exposures is adjusted based on multiple ideal transmittances that define the process of ideally changing from the first transmittance to the second transmittance in a change time that is equal to or less than the first threshold, and multiple first actual transmittances that define the process of realistically changing from the first transmittance to the second transmittance in a change time that is equal to or less than the first threshold.

[0012] A fourth aspect of the present disclosure is the control device according to the third aspect, in which the first threshold value is a value determined based on an ideal waiting time until the first transmittance changes to the second transmittance.

[0013] A fifth aspect of the present disclosure is a control device according to the third or fourth aspect, in which, when the change time exceeds a first threshold, a third transmittance is determined between the first transmittance and the second transmittance so that the change time is equal to or less than the first threshold, and multiple first actual transmittances are determined based on the first transmittance and the third transmittance.

[0014] A sixth aspect of the present disclosure is a control device according to the fifth aspect, in which the first threshold value when the change time exceeds the first threshold value and the difference between the first transmittance and the second transmittance falls within a predetermined range for a predetermined number of consecutive times is a value greater than the currently set value.

[0015] A seventh aspect of the present disclosure is a control device according to the sixth aspect, in which the first threshold value when the change time exceeds the first threshold value and the number of times the dissimilarity is within a predetermined range continues for a predetermined number of times is a value determined based on multiple change times obtained within the predetermined number of times.

[0016] An eighth aspect of the present disclosure is a control device according to the fifth aspect, in which multiple split exposures are maintained when the change time exceeds a first threshold value and the difference between the first transmittance and the second transmittance remains within a predetermined range for a predetermined number of consecutive times.

[0017] A ninth aspect of the present disclosure is a control device according to any one of the fifth to eighth aspects, which defines a process by which a plurality of first actual transmittances change from a first transmittance to a second transmittance when the change time is equal to or less than a first threshold value and the first actual transmittance changes from the first transmittance to a third transmittance to the second transmittance.

[0018] A tenth aspect of the present disclosure is a control device according to any one of the fifth to ninth aspects, wherein, when the change time exceeds a first threshold and a first maximum difference, which is the maximum difference between a plurality of ideal transmittances and a plurality of first actual transmittances, exceeds a predetermined difference, the divided exposure in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures is adjusted based on the plurality of ideal transmittances and a plurality of second actual transmittances that define the process of changing from the first transmittance via a plurality of intermediate transmittances to the second transmittance with a change time equal to or less than the first threshold, and the second maximum difference, which is the maximum difference between the plurality of intermediate transmittances and the plurality of ideal transmittances, is smaller than the first maximum difference.

[0019] An eleventh aspect of the present disclosure is a control device according to the tenth aspect, in which, when the first maximum difference exceeds a predetermined difference and the transmittance change time, which is the time required to change from the first transmittance to the third transmittance, is less than a second threshold, the split exposure in the process of changing from the first transmittance to the second transmittance among the multiple split exposures is adjusted based on the multiple ideal transmittances and the multiple second actual transmittances.

[0020] A twelfth aspect of the present disclosure is a control device according to any one of the third to eleventh aspects, in which adjustment to the split exposure during the process of changing from a first transmittance to a second transmittance among the multiple split exposures is achieved by adjusting at least one of the multiple exposure factors defining the split exposure based on the degree of difference between the ideal transmittance and the first actual transmittance.

[0021] A thirteenth aspect of the present disclosure is a control device according to any one of the third to twelfth aspects, in which the transmittance when the change time is equal to or less than a first threshold changes based on a plurality of ideal transmittances.

[0022] A fourteenth aspect of the present disclosure is a control device according to any one of the third to thirteenth aspects, wherein when the change time is equal to or less than a first threshold, the multiple split exposures correspond to multiple ideal transmittances.

[0023] A fifteenth aspect of the present disclosure is a control device according to any one of the third to fourteenth aspects, in which the plurality of ideal transmittances vary monotonically between a first transmittance and a second transmittance.

[0024] A sixteenth aspect of the present disclosure is a control device according to any one of the third to fifteenth aspects, wherein when the change time is equal to or less than a first threshold, the multiple split exposures change monotonically from the split exposure corresponding to the first transmittance to the target exposure.

[0025] A seventeenth aspect of the present disclosure is a control device according to any one of the third to sixteenth aspects, in which the imaging device is equipped with a movable aperture, and when the aperture is driven to achieve a target exposure, the first threshold value when the drive time of the aperture exceeds the first threshold value is a value equal to or greater than the drive time.

[0026] An eighteenth aspect of the present disclosure is an imaging device including the control device according to any one of the first to seventeenth aspects and an image sensor used for imaging.

[0027] A 19th aspect of the present disclosure is a control method that includes obtaining multiple split exposures determined based on a change time required for the transmittance of an electronic neutral density filter mounted on an imaging device to change from a first transmittance to a second transmittance that can achieve a target exposure of the imaging device and the target exposure, and performing control to apply the multiple split exposures to exposures of multiple frames obtained by imaging by the imaging device at least within the change time.

[0028] A twentieth aspect of the present disclosure is a program for causing a computer to execute processing including obtaining multiple split exposures determined based on the change time required for the transmittance of an electronic neutral density filter mounted on an imaging device to change from a first transmittance to a second transmittance that can achieve the target exposure of the imaging device and the target exposure, and performing control to apply the multiple split exposures to exposures of multiple frames obtained by imaging by the imaging device at least within the change time. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic diagram illustrating an example of the overall configuration of an imaging device. [Figure 2] FIG. 1 is a schematic diagram illustrating an example of a hardware configuration of an optical system and an electrical system of an imaging apparatus. [Figure 3] FIG. 10 is a conceptual diagram showing an example of how the brightness of a frame is monotonically changed by changing the transmittance of an electronic ND filter within a target number of frames. [Figure 4]FIG. 10 is a conceptual diagram showing an example of a situation in which the transmittance of the electronic ND filter is changed to achieve the target exposure, but the target exposure cannot be achieved within the target number of frames (i.e., the change in the transmittance of the electronic ND filter was not enough to reach the target number of frames). [Figure 5] FIG. 2 is a block diagram showing an example of how the system controller operates. [Figure 6] FIG. 4 is a conceptual diagram showing an example of a part of the processing contents of exposure control processing performed by a processor. [Figure 7] FIG. 4 is a conceptual diagram showing an example of a part of the processing contents of exposure control processing performed by a processor. [Figure 8] FIG. 4 is a conceptual diagram showing an example of a part of the processing contents of exposure control processing performed by a processor. [Figure 9] FIG. 4 is a conceptual diagram showing an example of a part of the processing contents of exposure control processing performed by a processor. [Figure 10] FIG. 4 is a conceptual diagram showing an example of a part of the processing contents of exposure control processing performed by a processor. [Figure 11A] 6 is a flowchart showing an example of the flow of exposure control processing according to the first embodiment. [Figure 11B] This is a continuation of the flowchart shown in FIG. 11A. [Figure 12A] 10 is a flowchart showing an example of the flow of exposure control processing according to the second embodiment. [Figure 12B] This is a continuation of the flowchart shown in FIG. 12A. [Figure 12C] This is a continuation of the flowchart shown in FIG. 12A. [Figure 13A] 11 is a flowchart showing an example of the flow of exposure control processing according to the third embodiment. [Figure 13B] This is a continuation of the flowchart shown in FIG. 13B. [Figure 14A] 13 is a flowchart showing an example of the flow of exposure control processing according to the fourth embodiment. [Figure 14B] This is a continuation of the flowchart shown in FIG. 14A. [Figure 14C] This is a continuation of the flowchart shown in FIG. 14B. [Figure 14D] This is a continuation of the flowchart shown in Figures 14B and 14C. [Figure 15] FIG. 13 is a conceptual diagram showing an example of a part of the processing content of exposure control processing according to the fourth embodiment, which is performed by a processor. [Figure 16] 13 is a flowchart showing an example of the flow of exposure control processing according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, examples of embodiments of a control device, an imaging device, a control method, and a program according to the present disclosure will be described with reference to the accompanying drawings.

[0031] First, the terms used in the following description will be explained.

[0032] CPU is an abbreviation for "Central Processing Unit". GPU is an abbreviation for "Graphics Processing Unit". GPGPU is an abbreviation for "General-purpose computing on graphics processing units". APU is an abbreviation for "Accelerated Processing Unit". TPU is an abbreviation for "Tensor processing unit". NVM is an abbreviation for "Non-volatile memory". RAM is an abbreviation for "Random Access Memory". IC is an abbreviation for "Integrated Circuit". ASIC is an abbreviation for "Application Specific Integrated Circuit". PLD is an abbreviation for "Programmable Logic Device". FPGA is an abbreviation for "Field-Programmable Gate Array". SoC is an abbreviation for "System-on-a-chip". SSD is an abbreviation for "Solid State Drive". USB is an abbreviation for "Universal Serial Bus". EEPROM is an abbreviation for "Electrically Erasable and Programmable Read Only Memory". I / F is an abbreviation for "Interface". UI is an abbreviation for "User Interface". CMOS is an abbreviation for "Complementary Metal Oxide Semiconductor". CCD is an abbreviation for "Charge Coupled Device". fps is an abbreviation for "Frames per second". MF is an abbreviation for "Manual focus". AF is an abbreviation for "Auto focus". AE is an abbreviation for "Auto Exposure". ND is an abbreviation for "Neutral Density". FIFO is an abbreviation for "First In First Out". EL is an abbreviation for "Electro Luminescence".

[0033] In the following description, a coded processor (hereinafter simply referred to as a "processor") may be a single physical or virtual computing device, or a combination of multiple physical or virtual computing devices. Furthermore, a processor may be a single type of computing device, or a combination of multiple types of computing devices. Examples of computing devices include a CPU, a GPU, a GPGPU, an APU, or a TPU.

[0034] In the following description, a signed memory is a memory such as a RAM in which information is temporarily stored, and is used as a work memory by a processor.

[0035] In the following description, the term "storage" refers to one or more nonvolatile storage devices that store various programs, various parameters, etc. Examples of nonvolatile storage devices include flash memory, magnetic disks, and magnetic tapes. Another example of storage is cloud storage.

[0036] In the following embodiments, the external I / F with a symbol controls the exchange of various information between multiple devices connected to each other. An example of the external I / F is a USB interface. A communication I / F including a communication processor, an antenna, etc. may be applied to the external I / F. The communication I / F controls communication between multiple computers. An example of a communication standard applied to the communication I / F is a wireless communication standard including 5G, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.

[0037] In the following embodiments, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. In addition, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed by connecting them with "and / or."

[0038] [First embodiment] As shown in FIG. 1 as an example, an imaging device 10 is a device that captures an image of a subject, and includes a system controller 12, an imaging device body 16, and an interchangeable lens 18. The imaging device 10 is an example of an "imaging device" according to the present disclosure, and the system controller 12 is an example of a "control device" and a "computer" according to the present disclosure. The system controller 12 is built into the imaging device body 16 and controls the entire imaging device 10. The interchangeable lens 18 is interchangeably attached to the imaging device body 16. The interchangeable lens 18 is provided with a focus ring 18A. The focus ring 18A is operated by a user of the imaging device 10 (hereinafter simply referred to as "user") when the user manually adjusts the focus of the imaging device 10 on a subject.

[0039] 1 shows an interchangeable-lens digital camera as an example of the imaging device 10, but this is merely an example and a fixed-lens digital camera may also be used. The present disclosure is also applicable to smart devices, wearable terminals, cinema cameras, television broadcasting video cameras, surveillance video cameras, endoscopes, cell observation devices, ophthalmic observation devices, surgical microscopes, etc. Smart devices, wearable terminals, cinema cameras, television broadcasting video cameras, surveillance video cameras, endoscopes, cell observation devices, ophthalmic observation devices, surgical microscopes, etc. are examples of the "imaging device" according to the present disclosure.

[0040] The imaging device body 16 is provided with an image sensor 20. The image sensor 20 is an example of an "image sensor" according to the present disclosure. The image sensor 20 is a CMOS image sensor. The image sensor 20 captures an image of a subject, which is the imaging target. When an interchangeable lens 18 is attached to the imaging device body 16, subject light, which is light representing the subject, passes through the interchangeable lens 18 and is focused on the image sensor 20, and image data representing the image of the subject is generated by the image sensor 20.

[0041] In the first embodiment, a CMOS image sensor is exemplified as the image sensor 20, but the present disclosure is not limited to this, and the present disclosure also applies when the image sensor 20 is another type of image sensor, such as a CCD image sensor.

[0042] A release button 22 and a dial 24 are provided on the top surface of the imaging device body 16. The dial 24 is operated when setting the operation mode of the imaging system and the operation mode of the playback system, and by operating the dial 24, the imaging device 10 is selectively set as an operation mode among the imaging mode, playback mode, and setting mode. The imaging mode is an operation mode that causes the imaging device 10 to capture an image. The image is captured by operating a mechanical shutter (not shown) and / or an electronic shutter (not shown). The playback mode is an operation mode that plays back images (e.g., still images and / or moving images) obtained by capturing an image for recording in the imaging mode. The setting mode is an operation mode that is set for the imaging device 10 when, for example, setting various setting values ​​used in image capture-related controls.

[0043] The release button 22 functions as an imaging preparation instruction section and an imaging instruction section, and is capable of detecting two stages of pressing operation: an imaging preparation instruction state and an imaging instruction state. The imaging preparation instruction state refers to a state in which the button is pressed from a standby position to an intermediate position (e.g., a half-pressed position), for example, and the imaging instruction state refers to a state in which the button is pressed beyond the intermediate position to a final pressed position (e.g., a fully pressed position). Depending on the configuration of the imaging device 10, the imaging preparation instruction state may be a state in which the user's finger is in contact with the release button 22, and the imaging instruction state may be a state in which the operating user's finger has moved from a state in which it is in contact with the release button 22 to a state in which it is released.

[0044] On the rear surface of the imaging device main body 16, instruction keys 26 and a touch panel display 32 are provided.

[0045] The touch panel display 32 includes a display 28 and a touch panel 30 (see also FIG. 2). An example of the display 28 is an EL display (e.g., an organic EL display or an inorganic EL display). The display 28 may be a different type of display, such as a liquid crystal display, instead of an EL display.

[0046] The display 28 displays images and / or text information, etc. When the imaging device 10 is in imaging mode, the display 28 is used to capture images for live view images, i.e., to display live view images obtained by continuous imaging. Here, a "live view image" refers to a moving image for display based on image data obtained by imaging by the image sensor 20. The imaging performed to obtain a live view image (hereinafter also referred to as "image capture for live view images") is performed based on a frame rate of, for example, 60 fps. 60 fps is merely an example, and a frame rate less than 60 fps (e.g., 30 fps) or greater than 60 fps (e.g., 180 fps) may also be used.

[0047] The display 28 is also used to display a still image obtained by capturing a still image when an instruction to capture a still image is given to the imaging device 10 via the release button 22. The display 28 is also used to display a playback image when the imaging device 10 is in playback mode. Furthermore, the display 28 is also used to display a menu screen on which various menus can be selected when the imaging device 10 is in setting mode, and a setting screen for setting various setting values ​​used in imaging-related controls.

[0048] The touch panel 30 is a transmissive touch panel that is overlaid on the surface of the display area of ​​the display 28. The touch panel 30 receives instructions from the user (for example, an instruction to prepare for imaging and / or an instruction to capture an image, etc.) by detecting contact with a pointer such as a finger or a stylus pen.

[0049] In the first embodiment, an out-cell type touch panel display in which the touch panel 30 is overlaid on the surface of the display area of ​​the display 28 is given as an example of the touch panel display 32, but this is merely an example. For example, an on-cell type or an in-cell type touch panel display can also be used as the touch panel display 32.

[0050] The instruction keys 26 accept various instructions. Here, "various instructions" refers to, for example, an instruction to display a menu screen, an instruction to select one or more menus, an instruction to confirm a selection, an instruction to erase a selection, an instruction to zoom in, zoom out, and frame-by-frame advance. These instructions may also be given via the touch panel 30.

[0051] As an example, as shown in FIG. 2, the image sensor 20 includes a photoelectric conversion element 72. The photoelectric conversion element 72 has a light-receiving surface 72A. The photoelectric conversion element 72 is disposed within the imaging device body 16 so that the center of the light-receiving surface 72A coincides with the optical axis OA (see also FIG. 1). The photoelectric conversion element 72 has a plurality of photosensitive pixels arranged in a matrix, and the light-receiving surface 72A is formed by the plurality of photosensitive pixels. Each photosensitive pixel has a microlens (not shown). Each photosensitive pixel is a physical pixel having a photodiode (not shown), which photoelectrically converts received light and outputs an electrical signal according to the amount of received light.

[0052] In addition, the multiple photosensitive pixels have red (R), green (G), or blue (B) color filters (not shown) arranged in a matrix in a predetermined pattern arrangement (e.g., Bayer arrangement, G-stripe R / G complete checkerboard, X-Trans (registered trademark) arrangement, honeycomb arrangement, etc.).

[0053] The interchangeable lens 18 includes an imaging lens 40. The imaging lens 40 has an objective lens 40A, a variable magnification lens 40B, and a movable diaphragm 40C. Here, the movable diaphragm 40C is an example of the "movable diaphragm" according to the present disclosure.

[0054] The objective lens 40A, the variable magnification lens 40B, and the aperture 40C are arranged in this order along the optical axis OA from the subject side (object side) to the imaging device body 16 side (image side).

[0055] The interchangeable lens 18 also includes a control device 36, a first actuator 37, and a second actuator 38. The control device 36 controls the entire interchangeable lens 18 in accordance with instructions from the imaging device body 16. The control device 36 is a device having a computer including, for example, a CPU, NVM, RAM, etc. The RAM of the control device 36 temporarily stores various types of information and is used as work memory. In the control device 36, the CPU reads necessary programs from the NVM and executes the various read programs on the RAM to control the entire imaging lens 40.

[0056] Although a device having a computer is given here as an example of the control device 36, this is merely an example, and devices including ASIC, FPGA, and / or PLD may also be applied. Furthermore, the control device 36 may be, for example, a device realized by a combination of hardware and software configurations.

[0057] The first actuator 37 includes a magnification change slide mechanism (not shown) and a magnification change motor (not shown). A magnification change lens 40B is attached to the magnification change slide mechanism so as to be slidable along the optical axis OA. A magnification change motor is also connected to the magnification change slide mechanism, and the magnification change slide mechanism operates by receiving power from the magnification change motor to move the magnification change lens 40B along the optical axis OA.

[0058] The second actuator 38 includes a power transmission mechanism (not shown) and an aperture motor (not shown). The aperture 40C has an opening 40C1, the size of which is variable. The opening 40C1 is formed, for example, by a plurality of aperture blades 40C2. The plurality of aperture blades 40C2 are connected to the power transmission mechanism. The power transmission mechanism is also connected to an aperture motor, which transmits the power of the aperture motor to the plurality of aperture blades 40C2. The plurality of aperture blades 40C2 operate in response to the power transmitted from the power transmission mechanism, thereby changing the size of the aperture 40C1. The aperture 40C adjusts the exposure by changing the size of the aperture 40C1.

[0059] The magnification motor and the aperture motor are connected to the control device 36, and the control device 36 controls the driving of each of the magnification motor and the aperture motor. In the first embodiment, a stepping motor is used as an example of the magnification motor and the aperture motor. Therefore, the magnification motor and the aperture motor operate in synchronization with pulse signals in response to commands from the control device 36. Also, while an example is shown here in which the magnification motor and the aperture motor are provided in the interchangeable lens 18, this is merely an example, and at least one of the magnification motor and the aperture motor may be provided in the imaging device body 16. The components and / or operation method of the interchangeable lens 18 can be changed as necessary.

[0060] In the imaging mode, the imaging device 10 selectively sets MF mode and AF mode in accordance with instructions given to the imaging device body 16. MF mode is an operating mode in which the focus is adjusted manually. In MF mode, for example, when the user operates the focus ring 18A or the like, the variable magnification lens 40B moves along the optical axis OA by an amount corresponding to the amount of operation of the focus ring 18A or the like, thereby adjusting the focus.

[0061] In AF mode, the imaging device body 16 calculates the in-focus position according to the subject distance, and adjusts the focus by moving the variable magnification lens 40B toward the calculated in-focus position. Here, the in-focus position refers to the position on the optical axis OA of the variable magnification lens 40B when the subject is in focus.

[0062] In the imaging mode, the imaging device 10 selectively sets either the manual exposure mode or the AE mode in accordance with instructions given to the imaging device body 16. The manual exposure mode is an operating mode in which exposure is adjusted manually, while the AE mode is an operating mode in which exposure is set automatically.

[0063] The imaging device main body 16 includes an image sensor 20, a system controller 12, an image memory 46, a UI device 48, an external I / F 50, a photoelectric conversion element driver 54, an ND filter driver 55, a motor driver 56, and an input / output interface 70. The image sensor 20 also includes a photoelectric conversion element 72 and an A / D converter 74.

[0064] The input / output interface 70 is connected to the system controller 12, image memory 46, UI device 48, external I / F 50, photoelectric conversion element driver 54, ND filter driver 55, motor driver 56, and A / D converter 74. The input / output interface 70 is also connected to the control device 36 of the interchangeable lens 18.

[0065] The system controller 12 includes a processor 64, storage 66, and memory 68. Here, the processor 64 is an example of a "processor" according to the present disclosure.

[0066] The processor 64, storage 66, and memory 68 are connected via a bus 75, which is connected to an input / output interface 70. Although the example shown in Fig. 2 shows a single bus as the bus 75 for convenience of illustration, multiple buses may be used. The bus 75 may be a serial bus or a parallel bus including a data bus, an address bus, a control bus, etc.

[0067] The storage 66 is a computer-readable non-transitory storage medium that stores various parameters and various programs. The various programs include an exposure control processing program PG (see FIG. 5), which will be described later. An example of the storage 66 is an EEPROM. The memory 68 temporarily stores various information and is used as a work memory. An example of the memory 68 is a RAM.

[0068] The processor 64 reads out a necessary program from the storage 66 and executes the read program in the memory 68. The processor 64 controls the entire imaging device 10 in accordance with the program executed on the memory 68. That is, in the example shown in Fig. 2, the image memory 46, the UI device 48, the external I / F 50, the photoelectric conversion element driver 54, the ND filter driver 55, the motor driver 56, the control device 36, etc. are controlled by the system controller 12.

[0069] The photoelectric conversion element 72 is connected to a photoelectric conversion element driver 54. The photoelectric conversion element driver 54 supplies an imaging timing signal that defines the timing of imaging performed by the photoelectric conversion element 72 to the photoelectric conversion element 72 in accordance with instructions from the processor 64. The photoelectric conversion element 72 performs resetting, exposure, and output of an electrical signal in accordance with the imaging timing signal supplied from the photoelectric conversion element driver 54. Examples of imaging timing signals include a vertical synchronization signal and a horizontal synchronization signal.

[0070] When the interchangeable lens 18 is attached to the imaging device body 16, subject light incident on the imaging lens 40 is imaged on the light-receiving surface 72A by the imaging lens 40. Under the control of the photoelectric conversion element driver 54, the photoelectric conversion element 72 photoelectrically converts the subject light received by the light-receiving surface 72A and outputs an electrical signal corresponding to the amount of subject light to the A / D converter 74 as analog image data indicating the subject light. Specifically, the A / D converter 74 reads out the analog image data from the photoelectric conversion element 72 in units of one frame and for each horizontal line using an exposure sequential readout method.

[0071] The A / D converter 74 digitizes the analog image data to generate a RAW image 79. The RAW image 79 is an image in which R pixels, G pixels, and B pixels are arranged in a mosaic pattern.

[0072] The processor 64 acquires the RAW image 79 from the A / D converter 74 and performs image processing on the acquired RAW image 79 .

[0073] The image memory 46 stores a frame 80. The frame 80 is an image obtained by the processor 64 performing image processing on the RAW image 79.

[0074] The UI device 48 includes a display 28, and the processor 64 displays various types of information on the display 28. The UI device 48 also includes a reception device 76. The reception device 76 includes a touch panel 30 and a hard key unit 78. The hard key unit 78 is a plurality of hard keys including the instruction keys 26 (see FIG. 1). The processor 64 operates in accordance with various instructions received by the touch panel 30.

[0075] The external I / F 50 controls the exchange of various information with devices external to the imaging device 10 (hereinafter also referred to as "external devices"). External devices (not shown), such as a smart device, a personal computer, a server, a USB memory, a memory card, and / or a printer, are directly or indirectly connected to the external I / F 50. The external I / F 50 is also connected to a network (not shown). The external I / F 50 controls the exchange of information between the system controller 12 and a communication device (not shown), such as a server on the network. For example, the external I / F 50 transmits information in response to a request from the system controller 12 to the communication device via the network. The external I / F 50 also receives information transmitted from the communication device and outputs the received information to the system controller 12 via the input / output interface 70.

[0076] The imaging device 10 includes an electronic ND filter 58 and a clear glass 60. Here, the electronic ND filter 58 is an example of an "electronic neutral density filter" according to the present disclosure. The electronic ND filter 58 and the clear glass 60 are mounted on the imaging device body 16. The electronic ND filter 58 and the clear glass 60 are disposed on the subject side of the light receiving surface 72A. The electronic ND filter 58 and the clear glass 60 are disposed in this order from the subject side to the image side. Note that, while an example in which the electronic ND filter 58 and the clear glass 60 are mounted on the imaging device body 16 has been given here, this is merely an example, and at least the electronic ND filter 58 of the electronic ND filter 58 and the clear glass 60 may be mounted on the interchangeable lens 18.

[0077] The electronic ND filter 58 is an electronic variable neutral density filter made of a material containing liquid crystal molecules whose orientation changes when a voltage is applied. The electronic ND filter 58 adjusts the amount of light passing through the electronic ND filter 58 by changing its transmittance depending on the applied voltage. The transmittance of the electronic ND filter 58 can be changed seamlessly. Therefore, for example, when the aperture value is maintained, the transmittance of the electronic ND filter 58 is changed to achieve a target exposure (e.g., appropriate exposure for the brightness of the subject captured by the image capture device 10) while maintaining the depth of field. Furthermore, when the aperture value is changed, the transmittance of the electronic ND filter 58 is changed to compensate for the increase or decrease in exposure that accompanies the change in aperture value, making it possible to maintain a constant exposure even while the aperture value is changing.

[0078] An ND filter driver 55 is connected to the electronic ND filter 58. The ND filter driver 55 controls the transmittance of the electronic ND filter 58 by applying a voltage to the electronic ND filter 58 in accordance with instructions from the system controller 12.

[0079] The clear glass 60 is a glass plate having light-transmitting properties. An example of a glass plate having light-transmitting properties is a transparent glass plate. The optical path length of the clear glass 60 is the same as the optical path length of the electronic ND filter 58.

[0080] The imaging device 10 includes a shift mechanism 62. The shift mechanism 62 is mounted on the imaging device body 16. The shift mechanism 62 has a motor 62A. An example of the motor 62A is a stepping motor. The shift mechanism 62 transmits power generated by the motor 62A to the electronic ND filter 58 and the clear glass 60, thereby shifting the electronic ND filter 58 and the clear glass 60 in a direction transverse to the optical axis OA.

[0081] A motor driver 56 is connected to the motor 62A, and the motor 62A operates under the control of the motor driver 56 in accordance with instructions from the system controller 12. The motor 62A is mechanically connected to the electronic ND filter 58 and the clear glass 60 via a plurality of gears. The motor 62A applies power to the electronic ND filter 58 and the clear glass 60 under the control of the motor driver 56 in accordance with instructions from the system controller 12, thereby selectively inserting the electronic ND filter 58 and the clear glass 60 into or removing them from the optical path.

[0082] A plurality of gears mechanically connecting the motor 62A to the electronic ND filter 58 and the clear glass 60 imparts power in the rotational direction of the motor 62A to the electronic ND filter 58, and power in the opposite direction to the rotational direction of the motor 62A to the clear glass 60. For example, when forward rotation power is generated by the motor 62A, forward rotation power is imparted to the electronic ND filter 58, and reverse rotation power is imparted to the clear glass 60. When reverse rotation power is generated by the motor 62A, forward rotation power is imparted to the clear glass 60, and reverse rotation power is imparted to the electronic ND filter 58. In this way, by applying power from the motor 62A to the electronic ND filter 58 and the clear glass 60, one of the electronic ND filter 58 and the clear glass 60 is inserted into the optical path, and the other is removed from the optical path. Since the optical path length of the electronic ND filter 58 and the optical path length of the clear glass 60 are the same, even if the electronic ND filter 58 is removed from the optical path, the clear glass 60 is inserted into the optical path, so the same optical path length as when the electronic ND filter 58 is inserted into the optical path is maintained.

[0083] 3, when multiple frames 80 are obtained by capturing live view images in AE mode, it is preferable to change the brightness of the frames 80 by a monotonous amount of brightness change rather than suddenly changing the brightness between the multiple frames 80 in the process of changing from the current frame 80 to the frame 80 that is the target number of frames A later. To do this, it is necessary to appropriately set the exposure applied to each of the multiple frames 80.

[0084] In the first embodiment, the imaging device 10 is equipped with the electronic ND filter 58, and therefore the exposure applied to the frame 80 is determined according to the transmittance of the electronic ND filter 58, the aperture value (i.e., F-number) of the aperture 40C, the shutter speed (for example, the shutter speed of the mechanical shutter when a mechanical shutter is used, or the shutter speed of the electronic shutter when an electronic shutter is used), and the sensitivity (for example, ISO sensitivity) of the photoelectric conversion element 72. Here, for example, in order to control the exposure of the frame 80 with the aperture value (hereinafter simply referred to as "aperture value") of the aperture 40C, the shutter speed, and the sensitivity (hereinafter simply referred to as "sensitivity") of the photoelectric conversion element 72 fixed, the transmittance of the electronic ND filter 58 is controlled.

[0085] The transmittance of the electronic ND filter 58 is set to the current transmittance TR, which is the transmittance of the electronic ND filter 58 at the timing when the image capture device 10 starts the exposure calculation. current Target exposure EX to make the brightness of frame 80 the target brightness target Achievable target transmittance TR target When changing to the current transmittance TR current and target transmittance TR target Depending on the relationship between current to target transmittance TR target The time required for the transmittance of the electronic ND filter 58 to change from the current transmittance TR to the current transmittance TR is different. current to target transmittance TR target, the difference in brightness between frames 80 also changes monotonically. If the target number of frames A and the required number of frames B (=(frame rate FR used in capturing live view images)×(change time T)), which is the number of frames required during the change time T, match, when frames 80 of the target number of frames A are obtained, the transmittance of the electronic ND filter 58 will reach the target transmittance TR target and accordingly, the target exposure EX target is also achieved.

[0086] However, as shown in Figure 4, the current transmittance TR current and target transmittance TR target Depending on the relationship between the number of required frames B and the target number of frames A, the required number of frames B may exceed the target number of frames A. In this case, the transmittance of the electronic ND filter 58 may reach the target transmittance TR by the time the frame 80 of the target number of frames A is obtained. target does not reach the target exposure EX target In the example shown in Figure 4, the target transmittance TR target Achieving and target exposure EX target The achievement of this is two frames behind the target frame number A.

[0087] Therefore, in the first embodiment, the target exposure EX target In order to achieve this and change the brightness of frames 80 with a monotonous brightness change amount until the target frame number A is reached, the processor 64 performs exposure control processing as shown in FIG. 5 as an example. An exposure control processing program PG is stored in the storage 66. The exposure control processing program PG is an example of a "program" according to the present disclosure. The processor 64 reads the exposure control processing program PG from the storage 66 and executes the read exposure control processing program PG in the memory 68. The exposure control processing is realized by the processor 64 executing the exposure control processing program PG. An example of the exposure control processing will be described below.

[0088] 6 to 10 show an example of the contents of the exposure control process performed by the processor 64. First, as shown in Fig. 6 as an example, when the timing to start exposure calculation arrives, the processor 64 calculates a photometric value 90 indicating the brightness of the subject based on a frame 80 obtained by capturing an image for a live view image. Note that the photometric value 90 may be measured by an exposure meter (not shown).

[0089] Based on the photometric value 90, the processor 64 calculates a target exposure EX as an exposure for adjusting the brightness of the frame 80 used to calculate the photometric value 90 to a target brightness. target The processor 64 also calculates the target exposure EX target Target transmittance TR corresponding to target , i.e., target exposure EX target Achievable target transmittance TR target For example, the target transmittance TR target is the shutter speed, aperture value, sensitivity, and target exposure EX currently set for the image capture device 10. target The target transmittance TR is calculated based on the target The calculation of is performed using a target transmittance calculation formula 91. The target transmittance calculation formula 91 is calculated based on the shutter speed, the aperture value, the sensitivity, and the target exposure EX target is the independent variable, and the target transmittance TR target is an arithmetic expression with as the dependent variable.

[0090] The processor 64 determines the transmittance currently set for the electronic ND filter 58, i.e., the current transmittance TR current Then, the processor 64 obtains the obtained current transmittance TR current The calculated target transmittance TR target The change time T1, which is the time required for the target transmittance TR to change to is calculated using a change time calculation formula 92. target and current transmittance TR current In the first embodiment, the target exposure EX target is an example of a "target exposure" according to the present disclosure, and the current transmittance TRcurrent is an example of the “first transmittance” according to the present disclosure, and the target transmittance TR target is an example of the "second transmittance" according to the present disclosure.

[0091] 7, the processor 64 determines whether the change time T1 exceeds a threshold value TH1. In the first embodiment, the threshold value TH1 is an example of a "first threshold value" according to the present disclosure. The threshold value TH1 is a value obtained by multiplying the transmittance of the electronic ND filter 58 by the current transmittance TR current to target transmittance TR target The ideal waiting time from the start of exposure calculation until the target exposure EX is reached under the condition that the aperture value, shutter speed, and sensitivity are fixed. target The threshold value TH1 may be a fixed value or a variable value that is changed according to given instructions or various conditions. An example of the threshold value TH1 is when the transmittance of the electronic ND filter 58 is equal to the current transmittance TR current to target transmittance TR target The ideal upper limit of the waiting time until the transmittance of the electronic ND filter 58 changes to the current transmittance TR current to target transmittance TR target The upper limit of the ideal waiting time until the transmittance of the electronic ND filter 58 changes to is merely an example, and may be a value that is below the upper limit within an allowable range. Furthermore, threshold value TH1 may be a time determined by the user, a time determined according to the type of imaging mode, or a time specified within a range of several percent to several tens of percent of the maximum time obtained from a table that defines the time it takes for the transmittance of the electronic ND filter 58 to change (for example, a time that corresponds to 50% of the maximum time obtained from a table that defines the time it takes for the transmittance of the electronic ND filter 58 to change).

[0092] If the change time T1 does not exceed the threshold value TH1 (in other words, if the magnitude relationship "change time T1≦threshold value TH1" holds), that is, if the transmittance of the electronic ND filter 58 is equal to or greater than the current transmittance TR current Target Exposure EX targetIf the time required for the image to change to the current image falls within an ideal time, processor 64 calculates a required number of frames B1, which is the number of frames required during the change time T1, based on the change time T1 and the frame rate FR (for example, a frame rate equivalent to the frame rate described above). For example, the required number of frames B1 is calculated by "(change time T1) x (frame rate FR)".

[0093] The processor 64 determines the target exposure EX target and the change time T1, a plurality of split exposures EX div Get multiple split exposures EX div Get the target exposure EX target and the number of frames required B1, multiple split exposures EX div This is achieved by calculating the multiple split exposures EX div The calculation of is performed using the divided exposure calculation formula 93. The divided exposure calculation formula 93 calculates the current transmittance TR current and Target Exposure EX target and the number of frames required B1 are used as independent variables, and multiple split exposure EX div is a calculation formula with the dependent variable as follows: div is the number of split exposures EX equivalent to the number of frames required B1. div is.

[0094] Multiple Split Exposure EX div is the current transmittance TR current Split Exposure EX div Target Exposure EX target For example, multiple split exposure EX div is the current transmittance TR current Split Exposure EX div Target Exposure EX target Although a linear change is illustrated here, an exponential change or a monotonous change is also acceptable.

[0095] Multiple Split Exposure EX div is the current transmittance TR current to target transmittance TRtarget The ideal process of change to (for example, current transmittance TR current to target transmittance TR target The current transmittance TR is determined by the process of changing the transmittance at a constant rate. current , multiple ideal transmittances TR ideal , and target transmittance TR target In the example shown in FIG. 7, the current transmittance TR current The ideal transmittance TR corresponds to "1", "2", "3", and "4" of the required number of frames B1. ideal corresponds to the required number of frames B1 of "5", and the target transmittance TR target The transmittance of the electronic ND filter 58 is currently TR current , multiple ideal transmittances TR ideal , and target transmittance TR target The current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target is the current transmittance TR current to target transmittance TR target In the example shown in Figure 7, the current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target However, the required number of frames B1 changes monotonically from "0" to "5".

[0096] Current transmittance TR current Split Exposure EX div Target Exposure EX target The monotonous change in exposure of frame 80 over the period is a change in the current transmittance TR with the shutter speed, sensitivity, and aperture value fixed. current , multiple ideal transmittances TR ideal , and target transmittance TR target , the current transmittance TR current to target transmittance TR target This is achieved by monotonically varying the current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target, the current transmittance TR current to target transmittance TR target As an example of monotonically changing the transmittance over current , multiple ideal transmittances TR ideal , and target transmittance TR target , the current transmittance TR current to target transmittance TR target For example, the image may be changed by a constant amount (for example, a linear or exponential amount) between frames 80 over a period of time.

[0097] The processor 64 outputs a plurality of split exposures EX for the exposure of a plurality of frames 80 obtained by capturing images for live view images within the change time T1. div For example, the processor 64 controls the application of the corresponding split exposure EX for each frame. div After setting the above, the camera controls the image capture. div The setting is, for example, a split exposure EX for the electronic ND filter 58 while maintaining the shutter speed, aperture value, and sensitivity. div In other words, the divided exposure EX calculated for each frame 80 div The transmittance of the electronic ND filter 58 is controlled while maintaining the shutter speed, aperture value, and sensitivity so that live view image capturing is performed.

[0098] On the other hand, as shown in FIG. 8, when the change time T1 exceeds the threshold value TH1, that is, when the current transmittance TR current Target Exposure EX target If the time required for the electronic ND filter 58 to change to is not within the ideal time, the processor 64 sets the transmittance of the electronic ND filter 58 to a time-varying transmittance TR, which is a transmittance for which the change time T1 falls within a range equal to or less than the threshold TH1. InTime is calculated using a transmittance calculation formula 94. The transmittance calculation formula 94 is calculated using a change time T1, a threshold value TH1, a current transmittance TR current , and target transmittance TR target is used as an independent variable, and the time-varying transmittance TR InTimeIn the first embodiment, the transmittance within the change time TR InTime is an example of the "third transmittance" according to the present disclosure.

[0099] The processor 64 sets the transmittance of the electronic ND filter 58 to the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target The change time T2, which is the time required to change the current transmittance TR to current , the change in transmittance over time TR InTime , and target transmittance TR target is an arithmetic expression with the independent variable and the change time T2 as the dependent variable.

[0100] Based on the change time T2 and the frame rate FR, the processor 64 calculates the required number of frames B2, which is the number of frames required for the change time T2 to pass. For example, the required number of frames B2 is calculated by "(change time T2) x (frame rate FR)".

[0101] The processor 64 determines the number of frames required, B2, and the target exposure, EX. target , and current transmittance TR current Based on multiple split exposure EX div Calculate multiple split exposures EX div The calculation of is performed using the divided exposure calculation formula 98. The divided exposure calculation formula 98 is based on the number of required frames B2, the target exposure EX target , and current transmittance TR current is used as an independent variable, and multiple split exposures EX div is a calculation formula with the dependent variable as follows: div The number of frames required is equivalent to the number of split exposures in B2. div is.

[0102] The processor 64 generates a plurality of split exposures EX div and multiple ideal transmittances TR based on known transmittances ideal and multiple real transmittance TR realHere, the known transmittance is the current transmittance TR current , target transmittance TR target , and the time-varying transmittance TR InTime Refers to multiple ideal transmittances TR ideal and multiple real transmittance TR real The transmittance calculation formula 100 is used to calculate the transmittance of a plurality of divided exposures EX div , current transmittance TR current , target transmittance TR target , and the time-varying transmittance TR InTime is used as an independent variable, and multiple ideal transmittances TR ideal and multiple real transmittance TR real is an arithmetic expression with as the dependent variable.

[0103] Multiple Reality Transmittance TR real indicates that the change time T2 is equal to or less than the threshold value TH1 and the transmittance of the electronic ND filter 58 is equal to the current transmittance TR current to target transmittance TR target Here, the realistic change is defined as the process of the current transmittance TR of the electronic ND filter 58. current to target transmittance TR target This refers to a change in transmittance that can be achieved within a time period that is equal to or shorter than the threshold value TH1. When the transmittance of the electronic ND filter 58 is actually changed, the current transmittance TR of the electronic ND filter 58 is changed to the current to target transmittance TR target Since priority is given to completing the change to the current transmittance TR within the time period equal to or shorter than the threshold value TH1, the transmittance of the electronic ND filter 58 is set to the current transmittance TR current to target transmittance TR target It does not change monotonically at a constant rate over time.

[0104] When the change time T1 exceeds the threshold TH1 and imaging for a live view image is performed, a plurality of actual transmittances TR real is set for the electronic ND filter 58. This is because, when imaging for a live view image is performed, even if the change time T1 exceeds the threshold TH1, multiple ideal transmittances TRideal When set, the current transmittance TR current to target transmittance TR target This is because the change to the threshold value TH1 is not completed within a time period equal to or shorter than the threshold value TH1.

[0105] In the example shown in FIG. 8, when the change time T2 is equal to or less than the threshold value TH1, the transmittance of the electronic ND filter 58 is equal to the current transmittance TR current to target transmittance TR target Multiple transmittances that realistically change from one to another, i.e., multiple real transmittances TR real As an example, when the change time T2 is equal to or less than the threshold value TH1 and the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target In the example shown in FIG. 8, the current transmittance TR current and target transmittance TR target Between these, the transmittance TR within the change time that makes the change time T2 equal to or less than the threshold value TH1 is InTime is defined. Multiple real transmittances TR real is the current transmittance TR current and the change in transmittance TR InTime That is, in the example shown in FIG. current Change in transmittance TR within time InTime A plurality of transmittances that change monotonically over time (for example, a plurality of transmittances that change linearly) are expressed as the transmittance within the change time TR InTime Multiple real transmittance TRs, including real It is defined as follows.

[0106] Current transmittance TR current and multiple real transmittance TR real is the current transmittance TR current Change in transmittance TR within time InTime In the example shown in Figure 8, the current transmittance TR current and multiple real transmittance TR real is the current transmittance TR current Change in transmittance TR within time InTime It changes linearly over

[0107] The processor 64 sets the transmittance of the electronic ND filter 58 to the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target However, if the transmittance of the electronic ND filter 58 is changed to the current transmittance TR while maintaining the shutter speed, aperture value, and sensitivity, current , multiple real transmittance TR real , and target transmittance TR target , the transmittance of the electronic ND filter 58 changes to the current transmittance TR while maintaining the shutter speed, aperture value, and sensitivity. current , multiple ideal transmittances TR ideal , and target transmittance TR target The change in brightness between frames 80 will be larger than if the brightness were to change according to the

[0108] Therefore, in the first embodiment, the transmittance of the electronic ND filter 58 is set to the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target , the transmittance of the electronic ND filter 58 is changed to the current transmittance TR while maintaining the shutter speed, aperture value, and sensitivity. current , multiple ideal transmittances TR ideal , and target transmittance TR target In order to change the brightness between frames 80 at the same level as when it changes according to real and multiple ideal transmittances TR ideal The difference δ1 in exposure between the frames 80 is calculated. The difference δ1 is an index showing the magnitude of the change in brightness between the frames 80. In other words, the difference δ1 is the degree of deviation from the ideal brightness of the frame 80 (i.e., the actual transmittance TR real The exposure and ideal transmittance TR achieved by ideal This represents the degree to which the exposure achieved by the

[0109] Since exposure is defined by the shutter speed, aperture value, and sensitivity in addition to the transmittance of the electronic ND filter 58, the difference δ1 can be made zero by adjusting the shutter speed, aperture value, and / or sensitivity. current , multiple real transmittance TR real , and target transmittance TR target Supports multiple split exposures EX div (i.e., current transmittance TR current to target transmittance TR target Each split exposure EX div ) based on the difference δ1. In other words, the processor 64 adjusts the current transmittance TR by complementing the difference δ1 with the shutter speed, the aperture value, and / or the sensitivity. current , multiple real transmittance TR real , and target transmittance TR target Supports multiple split exposures EX div , the current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target Supports multiple split exposures EX div In other words, for each frame 80 included in the required number of frames B2, the shutter speed, the aperture value, and / or the sensitivity are adjusted to match the actual transmittance TR real Split exposure achieved by EX div , the ideal transmittance TR ideal Split exposure achieved by EX div The difference δ1 is adjusted using an adjustment value corresponding to the difference δ1 (for example, an adjustment value determined according to the difference δ1) so as to achieve the above.

[0110] The transmittance of the electronic ND filter 58 is expressed as a number of actual transmittances TR. real When live view image capture is performed using the above, the difference δ1 is compensated for by adjusting the sensitivity with adjustment values ​​α1 to α4 for adjusting the sensitivity, as shown in Fig. 10. In this way, by adjusting the sensitivity with adjustment values ​​α1 to α4 according to the difference δ1, the transmittance of the electronic ND filter 58 is adjusted to the current transmittance TR current , multiple real transmittance TR real, and target transmittance TR target , the shutter speed, aperture value, and sensitivity are maintained, and the transmittance of the electronic ND filter 58 is changed according to real Split exposure EX at the same level as when using div is realized.

[0111] Each of the adjustment values ​​α1 to α4 is uniquely determined according to the difference δ1 calculated for each frame 80. For example, the adjustment values ​​α1 to α4 are calculated using an adjustment value calculation formula 102 in which the difference δ1 is an independent variable and an adjustment value for adjusting the sensitivity is a dependent variable. Note that while an example in which the sensitivity is adjusted according to the difference δ1 has been given here, this is merely an example, and the shutter speed and / or aperture value may also be adjusted according to the difference δ1. In this case, too, the adjustment values ​​for the shutter speed and / or aperture value may be calculated using a calculation formula similar to the adjustment value calculation formula 102.

[0112] When live view image capturing is performed within the change time T2, the processor 64 sets, for the image capturing device 10, the sensitivity adjusted in accordance with the difference δ1 calculated for each frame 80 as described above, the shutter speed determined for each frame 80, and the aperture value determined for each frame 80. The processor 64 also sets the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target is set as the transmittance of the electronic ND filter 58. In this way, in the imaging for the live view image within the change time T2, the sensitivity adjusted according to the difference δ1 calculated for each frame 80 as described above, the shutter speed determined for each frame 80, the aperture value determined for each frame 80, the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target By setting the exposure of the plurality of frames 80, a plurality of monotonically changing split exposures EX div applies.

[0113] In the first embodiment, imaging for live view images is an example of "imaging by an imaging device" according to the present disclosure. In the first embodiment, the change times T1 and T2 are an example of "change times" according to the present disclosure. In the first embodiment, the frame rate FR is an example of "default frame rate" according to the present disclosure. In the first embodiment, a plurality of ideal transmittances TR ideal is an example of the "plurality of ideal transmittances" according to the present disclosure. In the first embodiment, the plural actual transmittances TR real is an example of a "plurality of first actual transmittances" according to the present disclosure. In the first embodiment, the shutter speed, the aperture value, the sensitivity, and the transmittance of the electronic ND filter 58 are examples of a "plurality of exposure factors" according to the present disclosure. In the first embodiment, the difference δ1 is an example of a "degree of difference between the ideal transmittance and the first actual transmittance" according to the present disclosure.

[0114] Next, the operation of the image pickup device 10 will be described with reference to Figures 11A and 11B. Figures 11A and 11B show the current transmittance TR as the transmittance of the electronic ND filter 58. current 11A and 11B show an example of the flow of exposure control processing that is executed by processor 64 on the condition that exposure calculation start timing has arrived when image capturing for a live view image is performed in AF mode (in other words, the timing that has been specified in advance as the timing for adjusting the exposure of frame 80 obtained by image capturing for a live view image has arrived). The flow of exposure control processing shown in FIGS. 11A and 11B is an example of a "control method" according to the present disclosure.

[0115] 11A, first, in step ST10, processor 64 acquires frame 80 generated by capturing an image for a live view image. After the processing of step ST10 is executed, the exposure control processing proceeds to step ST12.

[0116] In step ST12, the processor 64 calculates a photometric value 90 based on the frame 80 acquired in step ST10. After the processing of step ST12 is executed, the exposure control processing proceeds to step ST14.

[0117] In step ST14, the processor 64 calculates the target exposure EX based on the photometric value 90 as the exposure for adjusting the brightness of the frame 80 used to calculate the photometric value 90 to the target brightness. target After the process of step ST14 is executed, the exposure control process proceeds to step ST16.

[0118] In step ST16, processor 64 calculates the target exposure EX target Target transmittance TR corresponding to target After the process of step ST16 is executed, the exposure control process proceeds to step ST18.

[0119] In step ST18, the processor 64 calculates the current transmittance TR currently set in the electronic ND filter 58. current After the process of step ST18 is executed, the exposure control process proceeds to step ST20.

[0120] In step ST20, the processor 64 sets the transmittance of the electronic ND filter 58 to the current transmittance TR current to target transmittance TR target After the process of step ST20 is executed, the exposure control process proceeds to step ST22.

[0121] In step ST22, processor 64 determines whether or not change time T1 exceeds threshold value TH1. If change time T1 does not exceed threshold value TH1 in step ST22, the determination is negative, and the exposure control process proceeds to step ST24. If change time T1 exceeds threshold value TH1 in step ST22, the determination is positive, and the exposure control process proceeds to step ST28 shown in FIG. 11B.

[0122] In step ST24, the processor 64 calculates the required number of frames B1 based on the change time T1 and the frame rate FR. After the processing of step ST24 is executed, the exposure control processing proceeds to step ST26.

[0123] In step ST26, the processor 64 calculates the number of frames required B1, the target exposure EX target , and current transmittance TR current Based on multiple split exposure EX div After the process of step ST26 is executed, the exposure control process proceeds to step ST42 shown in FIG.

[0124] In step ST28 shown in FIG. 11B, the processor 64 determines the transmittance of the electronic ND filter 58 as a transmittance within the change time TR, which is a transmittance within the change time T1 that falls within a range equal to or less than the threshold TH1. InTime The change time T1, the threshold TH1, and the current transmittance TR current , and target transmittance TR target After the process of step ST28 is executed, the exposure control process proceeds to step ST30.

[0125] In step ST30, the processor 64 sets the transmittance of the electronic ND filter 58 to the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target The time required to change the transmittance to the current transmittance TR, i.e., the change time T2, is current , the change in transmittance over time TR InTime , and target transmittance TR target After the process of step ST30 is executed, the exposure control process proceeds to step ST32.

[0126] In step ST32, the processor 64 calculates the required number of frames B2 based on the change time T2 and the frame rate FR. After the processing of step ST32 is executed, the exposure control processing proceeds to step ST34.

[0127] In step ST34, the processor 64 calculates the number of frames required B2, the target exposure EX target , and current transmittance TR current Based on multiple split exposure EX div After the process of step ST34 is executed, the exposure control process proceeds to step ST36.

[0128] In step ST36, processor 64 generates a plurality of split exposures EX div , current transmittance TR current , target transmittance TR target , and the time-varying transmittance TR InTime Based on multiple real-world transmittance TR real and multiple ideal transmittances TR ideal After the processing of step ST36 is executed, the exposure control processing proceeds to step ST38.

[0129] In step ST38, the processor 64 calculates a plurality of actual transmittances TR real and multiple ideal transmittances TR ideal That is, in step ST38, the difference Δ1 in exposure between the actual transmittance TR real and ideal transmittance TR ideal After the process of step ST38 is executed, the exposure control process proceeds to step ST40.

[0130] In step ST40, processor 64 performs split exposure EX for each frame 80 included in required number of frames B2. div The sensitivity, which is one of the exposure factors that define the difference Δ1, is adjusted by an adjustment value according to the difference Δ1. After the process of step ST40 is executed, the exposure control process proceeds to step ST42.

[0131] Here, if N is a natural number with an initial value of "1", in step ST42, the processor 64 calculates the divided exposure EX for the Nth frame. divFor example, when the exposure control process proceeds from step ST26 to step ST42, the processor 64 controls the image capturing device 10 to capture an image. div Split exposure EX for the Nth frame div On the other hand, when the exposure control process proceeds from step ST40 to step ST42, the processor 64 sets the sensitivity adjusted in accordance with the difference δ1 calculated for the Nth frame, the shutter speed determined for the Nth frame, and the aperture value determined for the Nth frame for the imaging device 10, and also sets the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target The electronic ND filter 58 is set to the transmittance for the N-th frame, and then the image capturing device 10 is caused to capture an image. After the processing of step ST42 is executed, the exposure control processing proceeds to step ST44.

[0132] In step ST44, the processor 64 determines whether the exposure of the Nth frame is the target exposure EX target In step ST44, it is determined whether the exposure of the Nth frame reaches the target exposure EX target If the exposure of the Nth frame does not reach the target exposure EX, the determination is negative, and the exposure control process proceeds to step ST46. In step ST46, the processor 64 adds "1" to N. After the process of step ST46 is executed, the exposure control process proceeds to step ST42. In step ST44, the exposure of the Nth frame is set to the target exposure EX. target If the value reaches , the determination is affirmative and the exposure control process ends.

[0133] As described above, in the imaging device 10 according to the first embodiment, live view image capturing is performed based on the frame rate FR, thereby obtaining a plurality of frames 80. current to target transmittance TR targetThe time required for the transmittance to change to the threshold TH1 (i.e., the current transmittance TR current to target transmittance TR target If the target exposure EX does not exceed the target exposure EX (a value determined based on the ideal waiting time until the target exposure EX changes to the target exposure EX), the required number of frames B1 (i.e., the number of frames required during the change time T1) is calculated based on the change time T1 and the frame rate FR. target and the number of frames required B1. div is applied to the exposures of the multiple frames 80 obtained by capturing images for live view images within the change time T1.

[0134] On the other hand, if the change time T1 exceeds the threshold TH1, the change time T2 (i.e., the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target The required number of frames B2 (i.e., the number of frames required for the change time T2 to elapse) is calculated based on the target exposure EX target and the number of frames required B2. div is applied to the exposures of the multiple frames 80 obtained by capturing images for live view images within the change time T2.

[0135] Therefore, according to the imaging device 10 of this first embodiment, it is possible to prevent the brightness between multiple frames 80 obtained by capturing images for live view images from suddenly changing due to switching of the transmittance of the electronic ND filter 58.

[0136] Furthermore, in the image capturing apparatus 10 according to the first embodiment, when the change time T1 exceeds the threshold value TH1, the transmittance of the electronic ND filter 58 is set to the current transmittance TR with the shutter speed, aperture value, and sensitivity fixed. current Change in transmittance TR within time InTime Target transmittance TR target A plurality of split exposures EX corresponding to a plurality of frames 80 when changing todiv is the number of ideal transmittances TR ideal (i.e., current transmittance TR current to target transmittance TR target Multiple transmittances that define the ideal process of change from real (That is, when the change time T2 is equal to or less than the threshold value TH1 and the transmittance of the electronic ND filter 58 is equal to the current transmittance TR current to target transmittance TR target Therefore, the current transmittance TR of the electronic ND filter 58 is adjusted based on the transmittance TR. current to target transmittance TR target realistic change to (i.e., current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR after target The exposure of multiple frames 80 can be tracked to the change in the image quality (change to ).

[0137] In the imaging device 10 according to the first embodiment, when the change time T1 exceeds the threshold value TH1, the current transmittance TR current and the transmittance within the change time TR InTime (i.e., the transmittance that makes the change time T1 equal to or less than the threshold TH1) real are defined. real is the time when the change time T2 is less than the threshold TH1 and the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target Current transmittance TR when changing to current to target transmittance TR target Then, when the shutter speed, aperture value, and sensitivity are fixed, the transmittance of the electronic ND filter 58 is set to the current transmittance TR current Change in transmittance TR within time InTime Target transmittance TR target A plurality of split exposures EX corresponding to a plurality of frames 80 when changing to div is the transmittance during the change time TR InTime Multiple real-world transmittances, including TR realand multiple ideal transmittances TR ideal Therefore, even if the change time T1 exceeds the threshold value TH1, the exposure of the plurality of frames 80 obtained by performing imaging for live view images is adjusted based on the plurality of divided exposures EX div can be applied.

[0138] In addition, in the image capturing apparatus 10 according to the first embodiment, the transmittance of the electronic ND filter 58 is set to the current transmittance TR when the shutter speed, aperture value, and sensitivity are fixed. current Change in transmittance TR within time InTime Target transmittance TR target A plurality of split exposures EX corresponding to a plurality of frames 80 when changing to div The adjustment is based on the difference δ1 (i.e., the actual transmittance TR real and ideal transmittance TR ideal This is achieved by adjusting the sensitivity with an adjustment value determined according to the actual transmittance TR real and ideal transmittance TR ideal Even if there is a gap between multiple ideal transmittances TR ideal Here, an example in which the sensitivity is adjusted is given, but this is merely an example, and it is sufficient if the adjustment value, sensitivity, shutter speed, and / or aperture value determined according to the difference δ1 are adjusted.

[0139] Furthermore, in the image capturing apparatus 10 according to the first embodiment, when the change time T1 is equal to or less than the threshold value TH1, the transmittance of the electronic ND filter 58 is changed to one of a plurality of ideal transmittances TR while the shutter speed, sensitivity, and aperture value are maintained. ideal Therefore, the current transmittance TR of the electronic ND filter 58 when the change time T1 is equal to or less than the threshold TH1 current to target transmittance TR target The exposure of multiple frames 80 can be easily tracked to changes in the image quality.

[0140] In addition, in the imaging device 10 according to the first embodiment, when the change time T1 is equal to or less than the threshold value TH1, the plurality of divided exposures EX div is the number of ideal transmittances TR ideal Therefore, the current transmittance TR of the electronic ND filter 58 when the change time T1 is equal to or less than the threshold TH1 is current to target transmittance TR target The exposure of multiple frames 80 can be easily tracked to changes in the image quality.

[0141] In addition, in the imaging device 10 according to the first embodiment, when the change time T1 is equal to or less than the threshold value TH1, a plurality of ideal transmittances TR ideal is the current transmittance TR current and target transmittance TR target Therefore, it is possible to suppress abrupt changes in brightness between a plurality of frames 80 obtained by capturing images for live view images.

[0142] In addition, in the imaging device 10 according to the first embodiment, when the change time T1 is equal to or less than the threshold value TH1, the plurality of divided exposures EX div However, the current transmittance TR current Split Exposure EX div Target Exposure EX target The current transmittance TR current Split Exposure EX div Target Exposure EX target The monotonous change in exposure of frame 80 over the period is a change in the current transmittance TR with the shutter speed, sensitivity, and aperture value fixed. current , multiple ideal transmittances TR ideal , and target transmittance TR target , the current transmittance TR current to target transmittance TR target This is achieved by monotonically changing the brightness over a period of time, thereby making it possible to suppress sudden changes in brightness between multiple frames 80 obtained by capturing images for live view images.

[0143] [Second embodiment] In the first embodiment described above, an example was given in which the threshold value TH1 is fixed regardless of the change time T1, but in this second embodiment, an example will be described in which the threshold value TH1 is changed depending on the change time T1.

[0144] In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In addition, in the second embodiment, the differences from the first embodiment will be mainly described.

[0145] In the second embodiment, an example of exposure control processing according to the second embodiment will be described with reference to the flowcharts shown in Figures 12A to 12C. However, since the flowcharts shown in Figures 12A to 12C include multiple steps that overlap with the flowcharts shown in Figures 11A and 11B described in the first embodiment, hereinafter, the same steps as those in the flowcharts shown in Figures 11A and 11B described in the first embodiment will be assigned the same step numbers, and descriptions thereof will be omitted.

[0146] The flowcharts shown in FIGS. 12A to 12C differ from the flowcharts shown in FIGS. 11A and 11B in that they include steps ST100 to ST132 instead of step ST22.

[0147] 12A, the processor 64 stores the change time T1 calculated in step ST20 in the memory 68 using the FIFO method. As a result, a plurality of change times T1 are stored in chronological order in the memory 68. After the processing of step ST100 is executed, the exposure control processing proceeds to step ST102.

[0148] In step ST102, the processor 64 determines whether the latest change time T1 stored in the memory 68 exceeds the threshold value TH1. If the latest change time T1 stored in the memory 68 does not exceed the threshold value TH1 in step ST102, the determination is negative, and the exposure control process proceeds to step ST118 shown in Fig. 12C. If the latest change time T1 stored in the memory 68 exceeds the threshold value TH1 in step ST102, the determination is positive, and the exposure control process proceeds to step ST104 shown in Fig. 12B.

[0149] In step ST104 shown in FIG. 12B, the processor 64 calculates the current transmittance TR under the condition that the shutter speed, the aperture value, and the sensitivity are fixed. current and target transmittance TR target The absolute value of the difference in exposure between the current transmittance TR and the current exposure current Exposure and target transmittance TR achieved by target The difference δ2, which is the absolute value of the difference from the actual exposure, is calculated. current and target transmittance TR target corresponds to the absolute value of the difference between

[0150] Although the absolute value of the difference is calculated in this example, a ratio may be applied instead of the absolute value of the difference. current and target transmittance TR target Since it corresponds to the absolute value of the difference between current and target transmittance TR target A measure of dissimilarity (for example, absolute value or percentage of difference) may be applied.

[0151] In the next step ST106, the processor 64 determines whether the difference δ2 is less than the threshold value TH2. The threshold value TH2 is a value indicating an exposure difference that realizes a change in brightness between frames 80 that exceeds a reference level. An example of an exposure difference that realizes a change in brightness between frames 80 that exceeds a reference level is an exposure difference when the change in brightness between frames 80 causes visual discomfort to the user. An example of the threshold value TH2 is a value that is determined in advance through tests using an actual device and / or computer simulation as a lower limit of the exposure difference when the change in brightness between frames 80 causes visual discomfort to the user. The lower limit of the exposure difference when the change in brightness between frames 80 causes visual discomfort to the user is merely an example and may be a value that exceeds the lower limit within an acceptable range. Furthermore, the threshold value TH2 may be a fixed value or a variable value that is changed in accordance with given instructions or various conditions. The threshold value TH2 may be a value determined by the user or a value determined according to the type of imaging mode.

[0152] In step ST106, if the difference δ2 is less than the threshold value TH, the determination is affirmative, and the exposure control process proceeds to step ST108. In step ST106, if the difference δ2 is not less than the threshold value TH2, the determination is negative, and the exposure control process proceeds to step ST110.

[0153] The small difference counter is used in the process of step ST108 and the process of step ST110. The small difference counter is used to calculate the current transmittance TR under the condition that the shutter speed, the aperture value, and the sensitivity are fixed. current Exposure and target transmittance TR achieved by target This counter counts the number of times that the state in which the difference from the exposure achieved by this method is small continues (i.e., the number of times that the determination result in step ST106 that "difference δ2<threshold TH2" continues). The initial count value of the small difference counter is "0".

[0154] In step ST108, the processor 64 adds 1 to the count value of the small difference counter. After the processing of step ST108 is executed, the exposure control processing proceeds to step ST112.

[0155] In step ST110, the processor 64 resets the count value of the small difference counter to the initial count value. After the process of step ST110 is executed, the exposure control process proceeds to step ST112.

[0156] In step ST112, the processor 64 determines whether the count value of the small difference counter exceeds the threshold value TH3. The threshold value TH3 is a value determined based on the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is likely to continue due to factors other than the subject brightness (e.g., noise) rather than the subject brightness. An example of the threshold value TH3 is a value determined in advance through testing using an actual device and / or computer simulation as an upper limit of the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is likely to continue due to factors other than the subject brightness rather than the subject brightness. The upper limit of the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is merely an example, and may be a value that is lower than the upper limit of the number of times that the determination is likely to continue due to factors other than the subject brightness rather than the subject brightness, within an acceptable range. The threshold value TH3 may be a fixed value or a variable value that is changed according to given instructions or various conditions. The threshold value TH3 may be a value determined by the user, or may be a value determined according to the type of imaging mode.

[0157] In step ST112, if the count value of the small dissimilarity counter does not exceed the threshold value TH3, the determination is negative, and the exposure control process proceeds to step ST28 shown in Fig. 11B. In step ST112, if the count value of the small dissimilarity counter exceeds the threshold value TH3, the determination is positive, and the exposure control process proceeds to step ST114.

[0158] In step ST114, the processor 64 changes the threshold value TH1 to a value greater than the currently set value. An example of a value greater than the currently set value is the longest change time. The longest change time refers to the longest change time T1 among the multiple change times T1 currently stored in the memory 68. Note that the longest change time is merely an example, and any change time T1 greater than the current threshold value TH1 among the multiple change times T1 currently stored in the memory 68 may be used. Alternatively, the threshold value TH1 may be changed to a value greater than the currently set value based on a rule (e.g., a rule that multiplies the threshold value TH1 by a coefficient that increases the threshold value TH1) that is determined independently of the multiple change times T1 currently stored in the memory 68. The degree to which the threshold value TH1 is increased may be determined based on a user instruction or various conditions. After the processing of step ST14 is executed, the exposure control processing proceeds to step ST116.

[0159] In step ST116, processor 64 turns on a threshold change flag, which is a flag indicating that threshold TH1 has been changed. After the process of step ST116 is executed, the exposure control process proceeds to step ST28 shown in FIG.

[0160] 12C, the processor 64 resets the count value of the small difference counter to the initial count value. After the process of step ST118 is executed, the exposure control process proceeds to step ST120.

[0161] In step ST120, processor 64 determines whether the threshold change flag is on. If the threshold change flag is not on in step ST120, the determination is negative, and the exposure control process proceeds to step ST24. If the threshold change flag is on in step ST120, the determination is positive, and the exposure control process proceeds to step ST122.

[0162] In step ST122, the processor 64 determines whether the latest change time T1 stored in the memory 68 is equal to or less than a default threshold value TH1. The default threshold value TH1 is a value that is determined in advance as a value smaller than the currently set threshold value TH1. In step ST122, if the latest change time T1 stored in the memory 68 is not equal to or less than the default threshold value TH1, the determination is negative, and the exposure control process proceeds to step ST24. In step ST122, if the latest change time T1 stored in the memory 68 is equal to or less than the default threshold value TH1, the determination is positive, and the exposure control process proceeds to step ST124.

[0163] In the process of step ST124, a short change time counter is used. The short change time counter is a counter that measures the number of times that the determination result in step ST122 that "change time T1≦default threshold TH1" continues. The initial count value of the short change time counter is "0".

[0164] In step ST124, the processor 64 adds 1 to the count value of the short change time counter. After the processing of step ST124 is executed, the exposure control processing proceeds to step ST126.

[0165] In step ST126, the processor 64 determines whether the count value of the short change time counter exceeds a threshold value TH4. The threshold value TH4 is a value determined based on the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is likely to continue due to factors other than the brightness of the subject (e.g., noise) rather than the brightness of the subject. An example of the threshold value TH4 is a value determined in advance through testing using an actual device and / or computer simulation as an upper limit of the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is likely to continue due to factors other than the brightness of the subject rather than the brightness of the subject. The upper limit of the number of times that the determination in step ST106 that "difference δ2 < threshold value TH2" is made is merely an example, and may be a value that is lower than the upper limit of the number of times that the determination in step ST106 is likely to continue due to factors other than the brightness of the subject, but within an acceptable range. The threshold value TH4 may be a fixed value or a variable value that is changed according to given instructions or various conditions. The threshold value TH4 may be a value determined by the user, or may be a value determined according to the type of imaging mode.

[0166] In step ST126, if the count value of the short change time counter does not exceed the threshold value TH4, the determination is negative, and the exposure control process proceeds to step ST24. In step ST126, if the count value of the short change time counter exceeds the threshold value TH4, the determination is positive, and the exposure control process proceeds to step ST128. The fact that the count value of the short change time counter has exceeded the threshold value TH4 means that there is a high possibility that there is almost no change in the brightness of the subject. In such a case, it is preferable to perform the processes of step ST24 and step ST26 shown in FIG. 12C rather than the processes of steps ST28 to ST40 shown in FIG. 11B. This is because the processes of step ST24 and step ST26 shown in FIG. 12C involve fewer steps and have a smaller processing load than the processes of steps ST28 to ST40 shown in FIG. 11B.

[0167] Therefore, in order to make it easier for the exposure control process to proceed to the processes of steps ST24 and ST26 shown in Fig. 11A rather than the processes of steps ST28 to ST40 shown in Fig. 11B, in step ST128, processor 64 changes the currently set threshold value TH1 to a default threshold value TH1. After the process of step ST128 is executed, the exposure control process proceeds to step ST130.

[0168] In step ST130, the processor 64 turns off the threshold change flag. After the processing of step ST130 is executed, the exposure control processing proceeds to step ST132.

[0169] In step ST132, the processor 64 resets the count value of the short change time counter to the initial count value. After the process of step ST132 is executed, the exposure control process proceeds to step ST24.

[0170] In the second embodiment, the difference δ2 is an example of the "difference between the first transmittance and the second transmittance" according to the present disclosure. Also, in the second embodiment, the count value of the small difference counter (see step ST112) is an example of the "number of times the difference between the first transmittance and the second transmittance falls within a predetermined range" according to the present disclosure. Also, in the second embodiment, the threshold value TH3 is an example of the "predetermined number of times" according to the present disclosure.

[0171] As described above, in the imaging device 10 according to the second embodiment, when the change time T1 exceeds the threshold value TH1 and the current transmittance TR current and target transmittance TR targetWhen the number of times that the degree of difference (difference δ2 in the second embodiment) between the threshold value TH1 and the actual value TH1 falls within a predetermined range (less than or equal to threshold value TH2 in the second embodiment) continues for a predetermined number of times (when the count value of the small difference counter exceeds threshold value TH3 in the second embodiment), threshold value TH1 is changed to a value greater than the currently set value. As a result, it becomes more difficult for the change time T1 to exceed threshold value TH1 than before threshold value TH1 was changed, and therefore the processing of steps ST24 and ST26 shown in FIG. 12C is more easily performed than the processing of steps ST28 to ST40 shown in FIG. 11B. The processing of steps ST24 and ST26 shown in FIG. 12C involves fewer steps than the processing of steps ST28 to ST40 shown in FIG. 11B, and therefore the processing load can be reduced.

[0172] In addition, if the change time T1 exceeds the threshold value TH1 and the current transmittance TR current and target transmittance TR target When the number of times that the degree of difference with the threshold value TH1 falls within the predetermined range continues a predetermined number of times (when the count value of the small difference counter exceeds the threshold value TH3 in the second embodiment), the threshold value TH1 is changed to a value (for example, the longest change time) determined based on the change time T1 obtained before the count value of the small difference counter exceeds the threshold value TH3. Therefore, compared to when the user determines the value of the threshold value TH1 after the change (i.e., when the threshold value TH1 is changed according to an instruction given by the user), the threshold value TH1 can be easily changed to a value that is difficult for the change time T1 to exceed.

[0173] [Third embodiment] In the second embodiment, when the change time T1 exceeds the threshold value TH1 and the current transmittance TR current and target transmittance TR target When the number of times that the degree of difference with the current transmittance falls within the predetermined range continues for a predetermined number of times, the processes of steps ST28 to ST40 shown in FIG. 11B are executed, and the transmittance of the electronic ND filter 58 is set to the current transmittance TR with the shutter speed, aperture value, and sensitivity fixed. current Change in transmittance TR within time InTime Target transmittance TRtarget A plurality of split exposures EX corresponding to a plurality of frames 80 when changing to div However, in the third embodiment, the sensitivity is adjusted by an adjustment value determined according to the difference δ1. current and target transmittance TR target If the difference between the two images falls within a predetermined range for a specified number of consecutive times, multiple split exposure EX div An example in which the above is maintained will be described.

[0174] In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be omitted. In the third embodiment, the differences from the second embodiment will be mainly described.

[0175] In this third embodiment, an example of exposure control processing according to this third embodiment will be described with reference to the flowcharts shown in Figures 13A and 13B. However, since the flowcharts shown in Figures 13A and 13B include multiple steps that overlap with the flowcharts shown in Figures 12A to 12C described in the second embodiment, hereinafter, of the multiple steps included in the flowcharts shown in Figures 13A and 13B, the same steps as those in the flowcharts shown in Figures 12A to 12C described in the second embodiment will be assigned the same step numbers, and descriptions thereof will be omitted.

[0176] The flowcharts shown in Figures 13A and 13B differ from the flowcharts shown in Figures 12A to 12C in that they have step ST200 instead of step ST102, that they have eliminated steps ST114 and ST116, and that they have eliminated steps ST120 to ST132.

[0177] In step ST200 shown in Fig. 13A, the processor 64 determines whether or not the latest change time T1 stored in the memory 68 exceeds the threshold value TH1. If the latest change time T1 stored in the memory 68 does not exceed the threshold value TH1 in step ST200, the determination is negative, and the exposure control process proceeds to step ST118 shown in Fig. 13B. If the latest change time T1 stored in the memory 68 exceeds the threshold value TH1 in step ST200, the determination is positive, and the exposure control process proceeds to step ST104.

[0178] If the determination in step ST112 shown in FIG. 13A is positive, the exposure control process proceeds to step ST202 shown in FIG. 13B.

[0179] In step ST202, the processor 64 calculates the currently calculated split exposures EX div (That is, the multiple split exposures EX34 calculated in step ST34 shown in FIG. 11B) div ) is stored in a divided exposure storage area, which is a predetermined storage area in the memory 68, so that the currently calculated divided exposures EX div After the process of step ST202 is executed, the exposure control process proceeds to step ST42 shown in FIG.

[0180] When the exposure control process proceeds from step ST202 to step ST42 shown in FIG. 11B, in step ST42 shown in FIG. 11B, processor 64 stores the divided exposure EXs stored in the divided exposure storage area. div Split exposure EX for the Nth frame div As a result, the image capturing device 10 is caused to capture an image. As a result, the divided exposure EX 100 stored in the divided exposure storage area is used for the exposure of the multiple frames 80 obtained by capturing an image for a live view image. div is applied to the multiple split exposures EX stored in the split exposure storage area. div is the currently calculated multiple split exposure EX div (That is, the multiple split exposures EX34 calculated in step ST34 shown in FIG. 11B)div ), and the processes of steps ST36 to ST40 shown in FIG. 11B do not need to be performed. This is because the divided exposure EX by the processes of steps ST36 to ST40 shown in FIG. div This means that frequent adjustments of the

[0181] [Fourth embodiment] In the first embodiment, regardless of the magnitude of the difference δ1, the sensitivity for each frame 80 is adjusted by an adjustment value determined according to the difference δ1, so that the divided exposure EX div Split Exposure EX is ideal div However, for example, the larger the difference δ1, the larger the sensitivity adjustment value, and therefore the noise that occurs with the sensitivity adjustment may also increase. Also, even if the shutter speed and aperture value, in addition to the sensitivity, are adjusted according to adjustment values ​​determined in accordance with the difference δ1, the larger the difference δ1, the larger the adjustment value, so the operation of the shutter and the operation of the aperture 40C imposes a large physical load on the shutter and the aperture 40C, which may be a factor in shortening the life of the shutter and the aperture 40C. Therefore, in the fourth embodiment, a divided exposure EX calculated as a realistic exposure is used. div Ideal for split exposure EX div An example of a configuration for suppressing the adjustment amount of the sensitivity and the like to achieve this will be described.

[0182] In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In the fourth embodiment, the differences from the first embodiment will be mainly described.

[0183] In the present fourth embodiment, an example of exposure control processing according to the present fourth embodiment will be described with reference to the flowcharts shown in Figures 14A to 14D. However, since the flowcharts shown in Figures 14A to 14D include multiple steps that overlap with the flowcharts shown in Figures 11A and 11B described in the first embodiment, hereinafter, of the multiple steps included in the flowcharts shown in Figures 14A to 14D, the same steps as those in the flowcharts shown in Figures 11A and 11B described in the first embodiment will be assigned the same step numbers, and descriptions thereof will be omitted.

[0184] The flowcharts shown in FIGS. 14A to 14D differ from the flowcharts shown in FIGS. 11A and 11B in that they include steps ST300 to ST316 instead of step ST40.

[0185] In the flowchart shown in Fig. 14A, after the process of step ST22 is executed, the exposure control process proceeds to step ST28 shown in Fig. 14B. In the flowchart shown in Fig. 14B, after the process of step ST38 is executed, the exposure control process proceeds to step ST300.

[0186] In step ST300, processor 64 determines whether the maximum value of difference δ1 calculated in step ST38 exceeds threshold value TH5. Here, the maximum value of difference δ1 is an example of the "first maximum dissimilarity" according to the present disclosure, and threshold value TH5 is an example of the "predetermined dissimilarity" according to the present disclosure.

[0187] The threshold value TH5 may be an upper limit value of the difference δ1 used to obtain an adjustment value that prevents the user from visually perceiving deterioration in image quality due to noise or the like that occurs when the sensitivity is adjusted using an adjustment value corresponding to the difference δ1. Note that the upper limit value is merely an example, and a value below the upper limit value within an acceptable range may also be used. Also, while an example of a form in which the sensitivity is adjusted is given here, this is merely an example, and the threshold value TH5 is determined in a similar manner even when the shutter speed and / or aperture value are adjusted.

[0188] The threshold value TH5 may be determined in advance through testing using an actual device and / or computer simulation as an upper limit value of the difference δ1 used to obtain an adjustment value that prevents the user from visually perceiving deterioration in image quality due to noise, etc., caused by adjusting the sensitivity. The upper limit value of the difference δ1 used to obtain an adjustment value that prevents the user from visually perceiving deterioration in image quality due to noise, etc., caused by adjusting the sensitivity is merely an example, and may be a value that is lower than the upper limit value of the difference δ1 used to obtain an adjustment value that prevents the user from visually perceiving deterioration in image quality due to noise, etc., caused by adjusting the sensitivity, within an acceptable range. Furthermore, the threshold value TH5 may be a fixed value or a variable value that is changed in accordance with given instructions or various conditions. The threshold value TH5 may be a value determined by the user or a value determined according to the type of imaging mode.

[0189] In step ST300, if the maximum value of the difference δ1 calculated in step ST38 does not exceed the threshold value TH5, the determination is negative, and the exposure control process proceeds to step ST24 shown in Fig. 14D. In step ST300, if the maximum value of the difference δ1 calculated in step ST38 exceeds the threshold value TH5, the determination is positive, and the exposure control process proceeds to step ST302.

[0190] In step ST302, the processor 64 calculates the current transmittance TR current Change in transmittance TR within time InTime The calculation of the change time T3 is performed in the same manner as the calculation of the change time T1 and the change time T2 described in the first embodiment. That is, the change time T3 is calculated by multiplying the current transmittance TR current and the transmittance within the change time TR InTime The exposure control process is performed using an arithmetic expression in which the independent variable is the change time T3 and the change time T4 is the dependent variable. After the process of step ST302 is performed, the exposure control process proceeds to step ST304.

[0191] In step ST304, the processor 64 determines whether the change time T3 is less than the threshold value TH6. Here, the change time T3 is an example of the "transmittance change time" according to the present disclosure, and the threshold value TH6 is an example of the "second threshold value" according to the present disclosure.

[0192] The threshold TH6 is the current transmittance TR current The transmittance TR is calculated by the time it changes from exposure to light. InTime This is the lower limit of the change time T3 at which noise generated by the sensitivity adjustment when the sensitivity is adjusted to change the exposure to that realized by (1) does not affect the image quality of the frame 80 at a visually perceptible level. The lower limit is merely an example, and a value above the lower limit may be used within an acceptable range. Furthermore, although an example in which the sensitivity is adjusted is given here, this is merely an example, and the threshold value TH6 is determined in a similar manner even when the shutter speed and / or aperture value is adjusted.

[0193] The threshold TH6 is the current transmittance TR current The transmittance TR is calculated by the time it changes from exposure to light. InTime The current transmittance TR may be determined in advance by testing an actual device and / or computer simulation as the lower limit of the change time T3 at which noise generated by the sensitivity adjustment does not affect the image quality of the frame 80 at a visually perceptible level when the sensitivity is adjusted to change the exposure to that realized by the current transmittance TR. current The transmittance TR is calculated by the time it changes from exposure to light. InTime The lower limit of the time at which noise caused by the sensitivity adjustment may affect the image quality of the frame 80 at a visually perceptible level when the sensitivity is adjusted to change the exposure to that realized by the current transmittance TR current The transmittance TR is calculated by the time it changes from exposure to light. InTimeThe threshold value TH6 may be a value that exceeds, within an acceptable range, the lower limit of the time during which noise caused by the sensitivity adjustment may have a visually perceptible effect on the image quality of the frame 80 when the sensitivity is adjusted to change the exposure to that achieved by the sensitivity adjustment. The threshold value TH6 may be a fixed value or a variable value that is changed in accordance with given instructions or various conditions. The threshold value TH6 may be a value determined by the user or a value determined according to the type of imaging mode.

[0194] In step ST304, if the change time T3 is not less than the threshold value TH6 (i.e., if the change time T3 is equal to or greater than the threshold value TH6), the determination is negative, and the exposure control process proceeds to step ST24 shown in Fig. 14D. As a result, the processes of step ST24 and step ST26 shown in Fig. 14D are executed in the same manner as in the first embodiment, and after the process of step ST26 is executed, the processes of steps ST42 to ST46 are executed. In step ST304, if the change time T3 is less than the threshold value TH6, the determination is negative, and the exposure control process proceeds to step ST306 shown in Fig. 14C.

[0195] In step ST306 shown in FIG. 14C, the processor 64 calculates a plurality of intermediate transmittances TR mid By calculating multiple real transmittances TR real (See Figure 15) The multiple intermediate transmittances TR mid The transmittance of the electronic ND filter 58 is currently TR current From multiple intermediate transmittance TR mid Target transmittance TR target The time required for the change to the ideal transmittance TR is equal to or less than the threshold value TH1, and ideal The maximum value of the difference δ3 between the transmittances 1 and 2 is smaller than the maximum value of the difference δ1. real (see FIG. 15) is an example of the "plurality of second actual transmittances" according to the present disclosure, and includes a plurality of intermediate transmittances TR midare an example of a "plurality of intermediate transmittances" according to the present disclosure, the maximum value of difference δ1 is an example of a "first maximum difference" according to the present disclosure, and the maximum value of difference δ3 is an example of a "second maximum difference" according to the present disclosure. After the processing of step ST306 is executed, the exposure control processing proceeds to step ST308.

[0196] In step ST308, the processor 64 sets the transmittance of the electronic ND filter 58 to the current transmittance TR current , multiple real transmittance TR real (See Figure 15), and the target transmittance TR target The change time T4 is calculated in the same manner as the calculation of the change time T1 and the change time T2 described in the first embodiment. The change time T4 is calculated based on the current transmittance TR current , multiple real transmittance TR real (See Figure 15), and the target transmittance TR target is calculated using an arithmetic expression with T2 as an independent variable and the change time T4 as a dependent variable. After the process of step ST308 is executed, the exposure control process proceeds to step ST310.

[0197] In step ST310, the processor 64 calculates a required number of frames B3, which is the number of frames required for the change time T4 to pass, based on the change time T4 and the frame rate FR, in the same manner as in the first embodiment. For example, the required number of frames B3 is calculated by "(change time T4) x (frame rate FR)". After the processing of step ST310 is executed, the exposure control processing proceeds to step ST312.

[0198] In step ST312, the processor 64 calculates the required frame count B3, the target exposure EX, and the like in the same manner as in the first embodiment. target , and current transmittance TR current Based on multiple split exposure EX div Calculate multiple split exposures EX div The calculation of EX is performed in the same manner as in the first embodiment. div Requires B3 frames, target exposure EXtarget , and current transmittance TR current is used as an independent variable, and multiple split exposures EX div After the process of step ST312 is executed, the exposure control process proceeds to step ST314.

[0199] In step ST314, the processor 64 calculates a plurality of actual transmittances TR for each frame 80 within the required number of frames B3 in the same manner as in the first embodiment. real and multiple ideal transmittances TR ideal That is, in step ST314, the actual transmittance TR real and ideal transmittance TR ideal After the process of step ST314 is executed, the exposure control process proceeds to step ST316.

[0200] In step ST316, the processor 64 performs split exposure EX316 for each frame 80 included in the required number of frames B3 in the same manner as in the first embodiment. div The sensitivity, which is one of the exposure factors that defines the difference Δ4, is adjusted by an adjustment value according to the difference Δ4 (see FIG. 15). After the process of step ST316 is executed, the exposure control process proceeds to step ST42 shown in FIG. 14D.

[0201] In step ST42 shown in FIG. 14D, the processor 64 executes the split exposure EX42 for the Nth frame. div For example, when the exposure control process proceeds from step ST26 to step ST42, the processor 64 controls the image capturing device 10 to capture an image. div Split exposure EX for the Nth frame div14C, the processor 64 sets the sensitivity adjusted in accordance with the difference Δ4 calculated for the Nth frame, the shutter speed determined for the Nth frame, and the aperture value determined for the Nth frame for the imaging device 10, and also sets the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target The transmittance for the N-th frame is set in the electronic ND filter 58, and then the imaging device 10 is caused to capture an image. That is, in the first embodiment, the difference δ1 is complemented by the sensitivity or the like, so that the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target Supports multiple split exposures EX div , the current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target Supports multiple split exposures EX div In contrast, in the fourth embodiment, the difference δ4 is compensated for by the sensitivity or the like, so that the current transmittance TR current , multiple real transmittance TR real , and target transmittance TR target Supports multiple split exposures EX div , the current transmittance TR current , multiple ideal transmittances TR ideal , and target transmittance TR target Supports multiple split exposures EX div (See Figure 15.)

[0202] As described above, in the imaging device 10 according to the fourth embodiment, the time-varying transmittance TR InTime Multiple real-world transmittances, including TR real Multiple real transmittances TR with smaller fluctuation range than real (i.e., the multiple intermediate transmittances TR shown in FIG. 15 mid Multiple real-world transmittances, including TR real ) and multiple ideal transmittances TR ideal(See FIG. 15) and the difference δ4 is calculated based on the difference δ4. Then, the sensitivity and other parameters are adjusted using an adjustment value determined according to the difference δ4, and the resulting multiple divided exposures EX div Ideal for multiple split exposures EX div Therefore, the exposure is adjusted so that the multiple split exposures EX div This allows for the reduction of the amount of adjustment required for adjustments using the sensitivity to the div This makes it possible to suppress the occurrence of problems that occur due to a large amount of adjustment required for adjustment using sensitivity to the signal.

[0203] In the fourth embodiment, when the change time T3 is less than the threshold value TH6, the transmittance within the change time TR InTime Multiple real-world transmittances, including TR real Multiple real transmittances TR with smaller fluctuation range than real (i.e., the multiple intermediate transmittances TR shown in FIG. 15 mid Multiple real-world transmittances, including TR real ) and multiple ideal transmittances TR ideal (See FIG. 15) and the difference δ4 is calculated based on the difference δ4. Then, the sensitivity and other parameters are adjusted using an adjustment value determined according to the difference δ4, and the resulting multiple divided exposures EX div Ideal for multiple split exposures EX div Therefore, the change time T3 is too short, so the split exposure EX div This can prevent the occurrence of a situation in which the amount of adjustment required for adjustment using sensitivity to the signal increases.

[0204] [Fifth embodiment] In the first embodiment, an example was given on the assumption that the aperture value is fixed. targetWhen the aperture value changes to achieve this (i.e., when the aperture 40C is driven), it is possible that the change time T1 does not fall within the drive time of the aperture 40C (i.e., the time required from when the drive of the aperture 40C starts to when the drive ends). Therefore, in the fifth embodiment, an example will be described in which the threshold value TH1 is set to the drive time of the aperture 40C when the change time T1 does not fall within the drive time of the aperture 40C.

[0205] In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In addition, in the fourth embodiment, the differences from the first embodiment will be mainly described.

[0206] In the fifth embodiment, an example of exposure control processing according to the fifth embodiment will be described with reference to the flowchart shown in Fig. 16. However, since the flowchart shown in Fig. 15 includes multiple steps that overlap with the flowcharts shown in Fig. 11A and 11B described in the first embodiment, hereinafter, of the multiple steps included in the flowchart shown in Fig. 15, the same steps as those in the flowcharts shown in Fig. 11A and 11B described in the first embodiment will be assigned the same step numbers, and descriptions thereof will be omitted.

[0207] The flowchart shown in FIG. 15 differs from the flowcharts shown in FIGS. 11A and 11B in that it includes steps ST400 to ST406 instead of steps ST16 and ST18.

[0208] In step ST400 shown in FIG. 15, processor 64 calculates the target exposure EX target Target transmittance TR corresponding to target and Target Exposure EX target and the target aperture value corresponding to the target transmittance TR target and target aperture, shutter speed, sensitivity, and target exposure EX target is the independent variable, and the target transmittance TR targetand the target aperture value as dependent variables. After the process of step ST400 is executed, the exposure control process proceeds to step ST402.

[0209] In step ST402, the processor 64 calculates the current transmittance TR current After the process of step ST402 is executed, the exposure control process proceeds to step ST404.

[0210] In step ST404, processor 64 determines whether aperture drive time T5 exceeds threshold value TH1. Here, aperture drive time T5 is the time it takes for aperture 40C to drive to achieve the target aperture value (in other words, the time it takes for aperture 40C to change from the current aperture value to the target aperture value). Aperture drive time T5 is calculated based on the current aperture value acquired in step ST402 and the target aperture value calculated in step ST400. For example, aperture drive time T5 is calculated using an arithmetic expression in which the current aperture value and the target aperture value are independent variables and aperture drive time T5 is a dependent variable.

[0211] In step ST404, if the aperture drive time T5 does not exceed the threshold value TH1, the exposure control process proceeds to step ST20. In step ST404, if the aperture drive time T5 exceeds the threshold value TH1, the exposure control process proceeds to step ST406.

[0212] In step ST406, the processor 64 sets the aperture drive time T5 as the threshold value TH1. That is, the current value of the threshold value TH1 is changed to the aperture drive time T5. Here, an example is given in which the current value of the threshold value TH1 is changed to the aperture drive time T5, but the current value of the threshold value TH1 may also be changed to a value that exceeds the aperture drive time T5 within an allowable range. The value that exceeds the aperture drive time T5 within an allowable range may be a fixed value or a variable value that is changed according to given instructions and / or various conditions. After the processing of step ST406 is executed, the exposure control processing proceeds to step ST20.

[0213] By doing so, the change time T1 falls within the aperture drive time T5, and therefore it is possible to suppress problems that arise due to the change time T1 not falling within the aperture drive time T5.

[0214] [Variations] In the above embodiments, various differences (e.g., differences δ1, δ2, δ3, and δ4) are calculated, but a ratio may be used instead of a difference, and any degree of dissimilarity between two comparison targets may be used. Also, in the above embodiments, an example is given in which a difference is compared with a threshold value, but when a ratio is compared with a threshold value instead of a difference, a threshold value corresponding to the ratio may be used instead of a threshold value corresponding to the difference.

[0215] In the above embodiments, the time required for the transmittance of the electronic ND filter 58 to change, that is, the change time (for example, change times T1, T2, T3, and T4), has been exemplified, but the number of frames may also be used as the change time. That is, the concept of change time may include the number of frames.

[0216] In the above embodiments, various maximum values ​​(such as the maximum value of the difference δ1 and the maximum value of the difference δ3) have been exemplified, but all of the above maximum values ​​mean maximum values ​​within a predetermined range.

[0217] In the above embodiments, monotonic changes have been exemplified, but monotonic changes refer to, for example, linear changes or exponential changes, etc. Furthermore, examples of monotonic changes include monotonic increases and decreases.

[0218] In each of the above embodiments, an example of exposure control processing when capturing images for live view images has been given, but the present disclosure is not limited to this, and the above-described exposure control processing can be applied when continuous image capturing is performed, such as when capturing images for recording moving images, when continuous image capturing is performed with a fixed image capturing interval, or when continuous image capturing is performed with a variable image capturing interval.

[0219] In the above embodiment, an example has been described in which the exposure control processing program PG is stored in the storage 66, but the present disclosure is not limited to this. For example, the exposure control processing program PG may be stored in a portable, computer-readable, non-transitory storage medium such as an SSD or a USB memory. The exposure control processing program PG stored in the non-transitory storage medium is installed in the system controller 12 of the imaging device 10. The processor 64 executes exposure control processing in accordance with the exposure control processing program PG.

[0220] Alternatively, the exposure control processing program PG may be stored in a storage device such as another computer or server device connected to the imaging device 10 via a network, and the exposure control processing program PG may be downloaded in response to a request from the imaging device 10 and installed in the system controller 12.

[0221] It is not necessary to store the entire exposure control processing program PG in a storage device such as another computer or server device connected to the imaging device 10, or in the storage 66; only a part of the exposure control processing program PG may be stored therein.

[0222] Furthermore, although the imaging device 10 shown in FIGS. 1 and 2 has a built-in system controller 12, the present disclosure is not limited to this. For example, the system controller 12 may be provided outside the imaging device 10.

[0223] In the above embodiment, the system controller 12 is exemplified, but the present disclosure is not limited to this, and a device including an ASIC, an FPGA, and / or a PLD may be applied instead of the system controller 12. Furthermore, instead of the system controller 12, a combination of a hardware configuration and a software configuration may be used.

[0224] The hardware resources for executing the exposure control process described in the above embodiments can be various processors, as listed below. Examples of processors include a CPU, which is a general-purpose processor that functions as a hardware resource for executing exposure control processes by executing software, i.e., a program. Examples of processors include dedicated electrical circuits, such as FPGAs, PLDs, or ASICs, which are processors with circuit configurations designed specifically for executing specific processes. Each processor has built-in or connected memory, and each processor uses the memory to execute the exposure control process.

[0225] The hardware resource that executes the exposure control process may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resource that executes the exposure control process may be a single processor.

[0226] As an example of a system configured with a single processor, first, one processor is configured by combining one or more CPUs and software, and this processor functions as a hardware resource that executes exposure control processing. Second, there is a system that uses a processor that realizes the functions of the entire system, including multiple hardware resources that execute exposure control processing, on a single IC chip, as typified by SoCs. In this way, the exposure control processing is realized using one or more of the above-mentioned various processors as hardware resources.

[0227] Furthermore, the hardware structure of these various processors can be, more specifically, an electric circuit that combines circuit elements such as semiconductor devices. The above exposure control process is merely an example. Therefore, it goes without saying that unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged, without departing from the spirit of the process.

[0228] The above-described description and illustrations are a detailed explanation of the parts related to the present disclosure and are merely an example of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or elements may be replaced with other parts from the above-described description and illustrations, as long as they do not deviate from the gist of the present disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the parts related to the present disclosure, the above-described description and illustrations omit explanations of common general technical knowledge that do not require particular explanation to enable the implementation of the present disclosure.

[0229] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

[0230] The following additional notes are provided regarding the above-described embodiments.

[0231] (Appendix 1) a processor; The processor is acquiring a plurality of divided exposures determined based on a change time required for a transmittance of an electronic neutral density filter mounted on an imaging device to change from a first transmittance to a second transmittance that can achieve a target exposure of the imaging device, and the target exposure; The divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures are adjusted based on a plurality of ideal transmittances that define a process of ideally changing from the first transmittance to the second transmittance in a time period that is equal to or less than the first threshold value, and a plurality of first actual transmittances that define a process of actually changing from the first transmittance to the second transmittance in a time period that is equal to or less than the first threshold value. Control device.

[0232] (Appendix 2) The divided exposures adjusted based on the ideal transmittances and the first actual transmittances are applied to exposures of a plurality of frames obtained by capturing images by the imaging device at least within the change time. 10. The control device of claim 1.

[0233] (Appendix 3) The adjustment of the divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures is realized by adjusting at least one of a plurality of exposure factors defining the divided exposures on a frame-by-frame basis based on a difference between the ideal transmittance and the first actual transmittance. 3. The control device according to claim 2.

[0234] (Appendix 4) The adjustment of the divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures is realized by adjusting at least one of a plurality of exposure factors defining the divided exposures on a frame-by-frame basis based on the degree of difference so that the exposure realized by the first actual transmittance becomes the exposure realized by the ideal transmittance. 4. The control device according to claim 3.

[0235] (Appendix 5) If the change time exceeds a first threshold, The processor adjusts the divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures based on the plurality of ideal transmittances and the plurality of first actual transmittances. 5. The control device according to any one of claims 1 to 4.

[0236] (Appendix 6) If the change time exceeds a first threshold, a third transmittance is defined between the first transmittance and the second transmittance, the third transmittance being such that the change time is equal to or shorter than the first threshold value; the plurality of first actual transmittances are determined based on the first transmittance and the third transmittance; When the number of times that the change time exceeds the first threshold value and the difference between the first transmittance and the second transmittance falls within a predetermined range continues a predetermined number of times, The processor changes the first threshold to a value greater than the currently set value. 6. The control device according to claim 5.

[0237] (Appendix 7) When the number of times that the change time exceeds the first threshold value and the difference between the first transmittance and the second transmittance falls within a predetermined range continues a predetermined number of times, The processor changes the first threshold to the maximum value of the change time obtained within the predetermined number of times. 7. The control device according to claim 6.

[0238] (Appendix 8) When the number of times that the change time exceeds a first threshold value and the difference between the first transmittance and the second transmittance falls within a predetermined range continues a predetermined number of times, The multiple split exposures are maintained, When the number of times that the change time exceeds the first threshold value and the difference between the first transmittance and the second transmittance is within a predetermined range is less than a predetermined number of times, a third transmittance is determined between the first transmittance and the second transmittance, the third transmittance being such that the change time is equal to or shorter than the first threshold value, and the plurality of first actual transmittances are determined based on the first transmittance and the third transmittance; 5. The control device according to any one of claims 1 to 4.

[0239] (Appendix 9) If the change time is equal to or less than the first threshold value, The processor varies the transmittance based on the plurality of ideal transmittances. 9. The control device according to any one of claims 1 to 8.

[0240] (Appendix 10) If the change time is equal to or less than the first threshold value, The processor monotonically varies the plurality of ideal transmittances between the first transmittance and the second transmittance to monotonically vary the plurality of split exposures. 10. The control device according to any one of claims 1 to 9.

[0241] (Appendix 11) The imaging device includes a movable diaphragm, If the drive time of the diaphragm when the diaphragm is driven to achieve the target exposure exceeds the first threshold value, The processor changes the first threshold to a value equal to or greater than the drive time. 11. The control device according to any one of claims 1 to 10. [Explanation of symbols]

[0242] 10. Imaging device 12 System Controller 16. Imaging device body 18 Interchangeable Lenses 18A Focus Ring 20 Image Sensor 22 Release button 24 Dial 26 Instruction keys 28 Display 30 Touch Panel 32 Touch Panel Display 36 Control device 37 First Actuator 38 Second Actuator 39 Third Actuator 40 Imaging lens 40A objective lens 40B variable magnification lens 40C aperture 40C1 opening 40C2 aperture blades 46 Image Memory 48 UI devices 50 External I / F 54 Photoelectric conversion element driver 55 ND filter driver 56 Motor Driver 58 Electronic ND Filter 60 Clear Glass 62 Shift mechanism 62A motor 64 processors 66 Storage 68 memory 70 Input / Output Interface 72 Photoelectric conversion element 72A Photosensitive surface 74 A / D converter 76 Reception Device 78 Hard key section 79 RAW images 80 frames 90 photometric values 91 Target transmittance calculation formula 92,96 Change time calculation formula 93 Split exposure calculation formula 94,100 Transmittance calculation formula 102 Adjustment value calculation formula A. Target frame count B, B1, B2, B3 Number of frames required EX div split exposure EX target target exposure FR Frame Rate OA optical axis PG Program T1, T2, T3, T4 change time T5 aperture drive time TH1, TH2, TH3, TH4, TH5, TH6 thresholds TR current Current transmittance TR ideal Ideal transmittance TR InTime Time transmittance TR mid intermediate transmittance TR real Reality Transmittance TR target Target transmission rate δ1, δ2, δ3, δ4 difference

Claims

1. a processor; The processor: acquiring a plurality of divided exposures determined based on a change time required for a transmittance of an electronic neutral density filter mounted on an imaging device to change from a first transmittance to a second transmittance that can achieve a target exposure of the imaging device, and the target exposure; Control is performed to apply the plurality of split exposures to exposures of a plurality of frames obtained by capturing images by the imaging device at least within the change time. Control device.

2. the plurality of frames are obtained by performing the imaging based on a default frame rate; the number of the plurality of frames is determined based on the change time and the predetermined frame rate; The plurality of split exposures are determined based on the target exposure and the number of shots. The control device according to claim 1 .

3. If the change time exceeds a first threshold, The divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures are adjusted based on a plurality of ideal transmittances that define a process of ideally changing from the first transmittance to the second transmittance with the change time being equal to or less than the first threshold, and a plurality of first actual transmittances that define a process of actually changing from the first transmittance to the second transmittance with the change time being equal to or less than the first threshold. The control device according to claim 1 .

4. The first threshold value is a value determined based on an ideal waiting time until the transmittance changes from the first transmittance to the second transmittance. The control device according to claim 3 .

5. If the change time exceeds the first threshold, a third transmittance is defined between the first transmittance and the second transmittance, which makes the change time equal to or shorter than the first threshold value; The plurality of first actual transmittances are determined based on the first transmittance and the third transmittance. The control device according to claim 3 .

6. When the number of times that the change time exceeds the first threshold and the difference between the first transmittance and the second transmittance falls within a predetermined range continues a predetermined number of times, the first threshold is a value greater than the currently set value. The control device according to claim 5 .

7. When the number of times that the change time exceeds the first threshold and the dissimilarity is within the predetermined range continues for the predetermined number of times, the first threshold is a value determined based on a plurality of the change times obtained within the predetermined number of times. The control device according to claim 6.

8. When the number of times that the change time exceeds the first threshold and the difference between the first transmittance and the second transmittance falls within a predetermined range continues a predetermined number of times, the multiple divided exposures are maintained. The control device according to claim 5 .

9. The plurality of first actual transmittances define a process of change from the first transmittance to the second transmittance when the change time is equal to or less than the first threshold and the change occurs from the first transmittance to the second transmittance via the third transmittance. The control device according to claim 5 .

10. When the change time exceeds the first threshold value and a first maximum difference between the plurality of ideal transmittances and the plurality of first actual transmittances exceeds a predetermined difference, The divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures are adjusted based on the plurality of ideal transmittances and a plurality of second actual transmittances that define a process of changing from the first transmittance to the second transmittance via a plurality of intermediate transmittances with the change time being equal to or less than the first threshold value, A second maximum difference between the plurality of intermediate transmittances and the plurality of ideal transmittances is smaller than the first maximum difference. The control device according to claim 5 .

11. When the first maximum difference exceeds the predetermined difference and a transmittance change time, which is a time required for the transmittance to change from the first transmittance to the third transmittance, is less than a second threshold value, The divided exposures in the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures are adjusted based on the plurality of ideal transmittances and the plurality of second actual transmittances. The control device according to claim 10.

12. The adjustment of the divided exposures during the process of changing from the first transmittance to the second transmittance among the plurality of divided exposures is realized by adjusting at least one of a plurality of exposure factors defining the divided exposures based on the degree of difference between the ideal transmittance and the first actual transmittance. The control device according to claim 3 .

13. When the change time is equal to or less than the first threshold, the transmittance changes based on the plurality of ideal transmittances. The control device according to claim 3 .

14. If the change time is equal to or less than the first threshold value, The plurality of split exposures correspond to the plurality of ideal transmittances. The control device according to claim 3 .

15. The plurality of ideal transmittances vary monotonically between the first transmittance and the second transmittance. The control device according to claim 3 .

16. If the change time is equal to or less than the first threshold value, The plurality of divided exposures vary monotonically from the divided exposure corresponding to the first transmittance to the target exposure. The control device according to claim 3 .

17. the imaging device includes a movable diaphragm; When the drive time of the diaphragm when the diaphragm is driven to achieve the target exposure exceeds the first threshold, the first threshold is a value equal to or greater than the drive time. The control device according to claim 3 .

18. A control device according to any one of claims 1 to 17; an image sensor used for the image capture; Imaging device.

19. acquiring a plurality of divided exposures determined based on a change time required for a transmittance of an electronic neutral density filter mounted on an image capture device to change from a first transmittance to a second transmittance that can achieve a target exposure of the image capture device, and the target exposure; and and performing control to apply the plurality of split exposures to exposures of a plurality of frames obtained by capturing images by the imaging device at least within the change time. Control method.

20. acquiring a plurality of divided exposures determined based on a change time required for a transmittance of an electronic neutral density filter mounted on an image capture device to change from a first transmittance to a second transmittance that can achieve a target exposure of the image capture device, and the target exposure; and A program for causing a computer to execute processing including control for applying the plurality of split exposures to exposures of a plurality of frames obtained by capturing images using the imaging device within at least the change time.

Images