Imaging device, exposure control method, and program

Abstract

This invention provides an imaging device, an exposure control method, and a program that enable natural exposure tracking during manual focus (MF) operation in full-time MF mode. [Solution] When full-time MF mode is set on camera 1 and images are being captured periodically, if the focus ring is not being operated by the user, the exposure at the time of shooting is adjusted using a second metering value calculated based on the brightness of a second region corresponding to the focal position at the time of image capture, which is narrower than the first region, and the first metering value. If the focus ring is being operated by the user, the exposure at the time of shooting is adjusted using a first metering value calculated based on the brightness of the first region of the captured image, without calculating a second metering value.

Description

Technical Field

[0001] The present invention relates to an imaging device, an exposure control method, and a program, and particularly to an imaging device, an exposure control method, and a program in which automatic exposure control is performed.

Background Art

[0002] In shooting using a digital camera, a technique for automatically performing exposure control by the function of AE (Auto Exposure) is known. As a function of AE, a function of performing exposure control so that a subject detected by a digital camera, such as a person's face, has an appropriate brightness is known. For example, in Patent Document 1, when there are a plurality of subjects within the angle of view, a method of determining a main subject based on the size of the subjects and adjusting the exposure according to the brightness of the main subject is disclosed. Further, in Patent Document 2, a method of further specifying the amount of change in the imaging area and adjusting the exposure based on the brightness of the main subject and the amount of change in the imaging area is disclosed.

[0003] Regarding focus control, there are an AF (Auto Focus) mode in which a digital camera automatically focuses and a MF (Manual Focus) mode in which a user can arbitrarily move the focus position by MF operation. Further, in recent years, there is also a hybrid method (hereinafter referred to as a full-time MF mode) that accepts MF operation by the user while in the AF mode.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, regardless of which exposure adjustment method is used in Patent Documents 1 or 2, exposure hunting may occur.

[0006] For example, consider the case shown in Figure 1, where manual focus is performed while panning the camera in full-time MF mode, and the focus is shifted from a bright background, mainly the sky, to a person in the foreground. In this case, the prior art described in Patent Documents 1 and 2 performs optimal AE for each state in which the angle of view and focus position change as shown in Figures 1(a), (b), and (c). Therefore, when transitioning from Figure 1(a) to Figure 1(b), the background area occupying the angle of view increases, and the exposure shifts toward becoming darker. On the other hand, in the state of Figure 1(c), the focus position is set to the face area of ​​the person, so a correction is applied to photograph the person brighter, and the exposure shifts toward becoming brighter. Consequently, in such cases, the exposure becomes dark in the state of Figure 1(b) and then brightens in the state of Figure 1(c), causing exposure hunting.

[0007] Therefore, the object of the present invention is to provide an imaging device, an exposure control method, and a program that enable natural exposure tracking during manual focus operation in full-time manual focus mode. [Means for solving the problem]

[0008] To solve the above problems, the imaging device according to claim 1 of the present invention comprises: an imaging means for capturing an image via an optical system; a setting means for setting the device to a mode that accepts user operation to change the focus position during autofocus execution; a calculation means for calculating a first photometric value based on the brightness of a first region of the captured image, and a second photometric value based on the brightness of a second region, which is narrower than the first region and corresponds to the focus position at the time of imaging, and the first photometric value; and an adjustment means for adjusting the exposure at the time of shooting. When the mode is set and the imaging means is periodically capturing an image, the adjustment means, if the user is operating to change the focus position, does not cause the calculation means to calculate the second photometric value, but adjusts the exposure using the first photometric value calculated by the calculation means, and if the user is not operating to change the focus position, adjusts the exposure using the second photometric value. [Effects of the Invention]

[0009] According to the present invention, natural exposure tracking is possible during manual focus operation in full-time MF mode. [Brief explanation of the drawing]

[0010] [Figure 1] This is an illustrative diagram illustrating the problems that this invention aims to solve. [Figure 2] This block diagram shows an overview of the hardware configuration of a camera as an imaging device according to an embodiment of the present invention. [Figure 3] This is a flowchart of the exposure control process according to an embodiment of the present invention. [Figure 4] Figure 3 is a flowchart of the calculation process for the second photometric value in step S308. [Figure 5] This is a schematic diagram illustrating the process in step S306 of Figure 3. [Modes for carrying out the invention]

[0011] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention to the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, the same or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] Figure 2 is a block diagram illustrating the hardware configuration of Camera 1 as an imaging device according to an embodiment of the present invention.

[0014] In Figure 2, camera 1 consists of a camera body 100 and a lens unit 200 that is detachable from the camera body 100. The configuration of camera 1 with the lens unit 200 attached to the camera body 100 will now be described with reference to Figure 2.

[0015] The camera body 100 includes a camera system control unit 101, a memory 102, an image sensor 103, a shutter 104, an A / D conversion unit 105, an image processing unit 106, a memory control unit 107, a D / A conversion unit 108, and a display unit 109. Furthermore, the camera body 100 includes a timing generator (hereinafter referred to as TG) 110, a release button 111, an operation unit 112, a detection unit 113, a photometering unit 114, a distance measuring unit 115, and an acceleration sensor 116.

[0016] The lens unit 200 also includes a lens system control unit 201, a photographic lens group 202, an aperture 203, and a focus ring 204.

[0017] The camera system control unit 101 is a control means for comprehensively controlling each part of the camera body 100. The memory 102 is a memory such as a RAM or a ROM connected to the camera system control unit 101. The imaging device 103 (imaging means) is an imaging device for imaging a charge accumulation type image such as a CMOS, and photoelectrically converts the light beam (optical image of the subject) incident through the lens unit 200 to output analog image data. The shutter 104 is controlled in its driving by a signal from the camera system control unit 101. The shutter 104 is switched and controlled between a light-shielding state in which the imaging device 103 is shielded from the light beam incident through the lens unit 200, and a retracted state in which the optical image of the subject incident through the lens unit 200 is guided to the imaging device 103.

[0018] The A / D conversion unit 105 is a conversion means for converting the analog image data output from the imaging device 103 into digital image data, and the converted digital image data is recorded in the memory 102. The image processing unit 106 performs predetermined image processing such as image interpolation, resizing such as reduction, color conversion processing, and arithmetic processing of the number of inaccurate pixel data such as saturated pixels and blacked-out pixels on the data from the A / D conversion unit 105 or the data from the memory control unit 107. The D / A conversion unit 108 is a conversion means for converting the digital image data recorded in the memory 102 into analog image data for display. The display unit 109 is a display means composed of a TFT type LCD (thin film transistor drive type liquid crystal display) or the like, and can display the analog image data for display. The display unit 109 can also perform live view display by sequentially displaying the analog image data output from the D / A conversion unit 108. Note that various information other than the acquired image data can also be displayed on the display unit 109. [[ID=?]] [[ID=?]]

[0019] [[ID=?]] TG110 is a timing generation means for transmitting the timing related to the operations in the camera 1, such as the exposure timing and frame rate change of the imaging device 103, and the switching timing between the light-shielding state and the retracted state by the shutter 104, to each part of the camera 1.

[0020] There seems to be some incorrect "ID=?" in the original provided content which are left as they are in the translation. If this is a mistake in the original, it might need to be corrected for a more accurate representation.The release button 111 and the operation unit 112 are operation means for inputting various operation instructions to the camera system control unit 101. The release button 111 is an instruction means for instructing the start of the imaging preparation operation and the imaging operation. When the user performs a change operation (e.g., half-press) to set the state of the release button 111 to the SW1 state, the start of the imaging preparation operation is instructed, and distance measurement calculation processing, photometry calculation processing, etc. are started. Also, when the user performs a change operation (e.g., full-press) to set the state of the release button 111 to the SW2 state, the start of the imaging operation is instructed, and a series of processes until the subject is imaged and an image is acquired are started. The operation unit 112 is an input device group composed of operation members for the user to perform various instructions and settings on the camera body 100, such as switches, buttons, dials, etc. For example, the operation unit 112 includes a power switch, a menu button, a direction indicator button, etc. Note that the display unit 109 may be a touch panel display in which a TFT-type LCD and a capacitive touch panel are integrally configured, and a configuration may be adopted such that information input similar to that when the operation unit 112 is operated can be performed by operating the UI displayed on the display unit 109.

[0021] In the detection unit 113, detection processing of a specific subject is performed using the image data obtained from the image processing unit 106. In the photometry unit 114, photometry calculation is performed using the image data obtained from the image processing unit 106. In the distance measurement unit 115, distance measurement calculation is performed using the image data obtained from the image processing unit 106. In the acceleration sensor 116, when the camera 1 is panned, etc., the acceleration is detected to detect the moving speed of the camera 1.

[0022] Note that the above-described detection unit 113 and photometry unit 114 may be configured to be provided integrally with the camera system control unit 101. In this case, the camera system control unit 101 executes various calculations in the above-described detection unit 113 and photometry unit 114.

[0023] The lens system control unit 201 is a control means that comprehensively controls the operation of the lens unit 200. When the lens unit 200 is attached to the camera body 100, the lens system control unit 201 and the camera system control unit 101 can communicate via an interface (not shown). For example, in response to instructions from the camera system control unit 101, information regarding the lens unit 200 attached to the camera body 100 is output to the camera system control unit 101.

[0024] The photographic lens group 202 (optical system) is a lens group consisting of multiple lenses, including optical axis shift lenses, zoom lenses, and focus lenses. The aperture 203 (optical system) is a light intensity adjustment member for adjusting the amount of light beam transmitted through the inside of the photographic lens group 202, and its drive is controlled by the lens system control unit 201. Note that the lens unit 200 may not have a lens system control unit 201. In this configuration, the operation of the photographic lens group 202 and the aperture 203 is controlled by instructions from the camera system control unit 101.

[0025] The focus ring 204 is a ring provided on the outer circumference of the lens unit 200, and is a component that adjusts the position of the photographic lens group 202 and changes the focal position in response to the user's rotation of the focus ring 204. The amount of rotation of the focus ring 204 due to this rotation operation is input to the lens system control unit 201, which then controls the position adjustment of the photographic lens group 202 according to that amount of rotation. Hereinafter, this operation by the user to change the focal position, which is the rotation operation of the focus ring 204, will be referred to as MF (manual focus) operation.

[0026] Camera 1 may also be provided with a recording medium 300, such as a memory card or hard disk, capable of recording image data stored in memory 102. Here, the recording medium 300 is exemplified as a recording medium that can be inserted into and removed from the camera body 100, such as a memory card, but is not limited to this. For example, the recording medium 300 may be an optical disk such as a DVD-RW disc or a magnetic disk such as a hard disk. Furthermore, the recording medium 300 may not be removable but may be pre-built into the camera body 100.

[0027] The above describes the basic configuration of the camera 1 according to this embodiment.

[0028] The exposure control process according to an embodiment of the present invention will be described below with reference to the flowchart in Figure 3. This process is executed by the camera system control unit 101, which expands the program stored in ROM in memory 102 into RAM, which is also located in memory 102.

[0029] First, in step S301, the camera system control unit 101 determines whether the focus mode selected by the user using the operation unit 112 (setting means) is full-time MF. If it is full-time MF mode (YES in step S301), the process proceeds to step S302. In this embodiment, the user can select one of the following as the focus mode: AF (autofocus) mode, MF (manual focus) mode, or full-time MF mode. Full-time MF mode is a hybrid mode that accepts MF operation by the user while AF is being performed.

[0030] In step S302, the camera system control unit 101 acquires the latest frame image based on the subject image captured via the image sensor 103 and displays the live view image on the display unit 109. The camera system control unit 101 controls the camera 1 to periodically capture images and acquire frame images until the release button is pressed in step S309, which will be described later, and the calculations from step S302 onward are performed using this latest frame image.

[0031] In step S303, the camera system control unit 101 determines whether the user is performing an MF operation. Here, if the user has not performed an MF operation for a certain threshold time or longer, it is determined that the user is not performing an MF operation (NO in step S303), and the process proceeds to step S307. Otherwise, it is determined that the user is performing an MF operation (YES in step S303), and the process proceeds to step S304. This is because if the determination of whether the user is performing an MF operation were based on the latest state, the determination result might change frequently, so a certain time interval is set to stabilize the determination result.

[0032] First, we will explain the case where, in step S303, the camera system control unit 101 determines that the user is not currently performing an MF operation, and the system proceeds to step S307.

[0033] In step S307, the detection unit 113 uses autofocus to detect an object region (second region) corresponding to the focal position during imaging (object region detection means). Here, the image processing unit 106 generates a reduced image by reducing the latest frame image acquired in step S302, and the detection unit 113 performs object region detection on the acquired reduced image. Common types of object regions include the face and pupil regions of people and animals, and the regions of important parts of vehicles such as cars and trains. The method for detecting this object region can be a known method, such as using training data from a neural network (see, for example, Japanese Patent Application Publication No. 2006-39666).

[0034] Next, in step S308, the photometric unit 114 performs the calculation process for the second photometric value (calculation means). This detailed process will be explained using the flowchart in Figure 4.

[0035] In step S401, the photometer 114 calculates a first photometric value indicating the brightness of the entire field of view (first area) (calculation means). Here, the photometer 114 divides the entire field of view or a certain range into blocks and calculates the first photometric value based on the brightness (BV value) of each block. For example, the first photometric value is calculated using a simple average of the BV values ​​of each block or a weighted average where the weight increases towards the center of the field of view.

[0036] In step S402, the photometer 114 calculates the brightness of the object region detected in step S307. Here, the average value of the BV values ​​of the blocks corresponding to the object region detected in step S307 is calculated as the brightness of the object region.

[0037] In step S403, the photometer 114 acquires the target brightness of the object. Here, the target brightness is set in advance for each type of detectable object, and the target brightness is acquired according to the type of object detected in step S307. Specifically, if the object is an animal, the first photometric value calculated in step S401 is set as the target brightness, and if the object is a person, the brightness is set to the first photometric value plus 1 stop.

[0038] In step S404, the photometer 114 calculates the final photometric value. Here, it is set by balancing the brightness based on the brightness of the entire field of view (first photometric value), the brightness of the object area, and the brightness of the target, which were calculated and acquired in steps S401 to S403. This final photometric value is designated as the second photometric value. From this second photometric value, the camera system control unit 101 controls each part of the imaging device 1 in step S302 to adjust the exposure during shooting so that the images captured periodically have an appropriate brightness. After this, the process shown in Figure 4 is completed, and the process proceeds to step S309 (adjustment means). Specifically, the exposure can be adjusted by adjusting the exposure time, aperture value, ISO sensitivity, etc., for the shutter 104, aperture 203, and image sensor 103.

[0039] Next, we will describe the case where, in step S303, the camera system control unit 101 determines that the user is performing an MF operation, and the system proceeds to step S304.

[0040] In step S304, the photometer 114 calculates the first photometric value. This can be the same process as in step S401. However, the processes in steps S402 to S404 in Figure 4, namely the calculation and acquisition of the brightness of the object area and the brightness of the target object, and the calculation of the second photometric value from the first photometric value and these calculated and acquired brightness values, are not performed here. This is because, during MF operation, it is not possible to determine the main subject, so performing exposure control based on the second photometric value could lead to the exposure fluctuating.

[0041] In step S305, the camera system control unit 101 detects the angle of view change speed (detection means). Here, the camera system control unit 101 detects the angle of view change speed using information such as the movement speed of the camera 1 detected by the acceleration sensor 116, or the time-series changes of the captured image frames calculated by the image processing unit 106. When using the time-series changes of the captured image frames, it is possible not only to detect the angle of view change speed, but also to detect scene changes such as when a subject crosses the frame or when the light source changes.

[0042] In step S306, the photometer 114 corrects the first photometric value calculated in step S304 and obtains the target photometric value. Based on this target photometric value, the camera system control unit 101 controls each part of the imaging device 1 to adjust the exposure during shooting so that the images periodically captured in step S302 have an appropriate brightness, and then proceeds to step S309 (adjustment means).

[0043] Here, the process in step S306 will be explained using the schematic diagram in Figure 5.

[0044] Figure 5 shows the full-time MF mode, with the horizontal axis representing time progression and the vertical axis representing the photometric value. The period from Ta to Tc represents the time when the scene changes due to panning operations of camera 1, and the period from Tb to Td represents the time when MF operation is in progress. The dotted line Ea shows the change in photometric value when, from Ta to Td, a first photometric value indicating the brightness of the entire field of view is calculated, and after the MF operation ends at Td, steps S307 and S308 are executed to calculate the second photometric value. On the other hand, the solid line Eb shows the change in photometric value when, from Ta to Td, steps S304 to S306 are executed to calculate the target photometric value, and after the MF operation ends at Td, steps S307 and S308 are executed to calculate the second photometric value.

[0045] First, let's explain the dotted line Ea. Between Ta and Tc, the metering value changes in accordance with the change in brightness of the entire field of view due to the scene change. Between Tc and Td, there is no scene change, so the metering value shown by the dotted line Ea maintains the first metering value calculated for the field of view at Tc. However, when the MF operation ends at Td, AF is restarted and converges to the metering value shown by the dotted line Ea. Here, as shown in Figure 5, the metering value may change in opposite directions between Ta and Tc and after Td, which causes a problem of brightness hunting.

[0046] In this embodiment, in consideration of this problem, the first photometric value is corrected so that the change in the photometric value is as shown by the solid line Eb. Specifically, between Ta and Tb, the solid line Eb changes in the same way as the dotted line Ea. However, between Tb and Tc, when MF operation is performed simultaneously with the scene change, steps S304 to S306 are executed. In step S306, the amount or rate of change of the solid line Eb with respect to the photometric value (Etb) at Tb at the start of the MF operation is made smaller than the amount or rate of change of the dotted line Ea. That is, the target photometric value between Tb and Tc is the value obtained by correcting the first photometric value. For example, this can be calculated using the following equation (1). Eb = Etb - α × (Etb - Et) (1)

[0047] In equation (1), Etb is the photometric value at time Tb, Et is the first photometric value calculated at the current angle of view, and Eb is the current photometric value (target photometric value) after this correction. α is a correction coefficient, set to a value between 0 and 1. Here, the value of α may be a fixed coefficient, but it may also be determined so that it becomes larger as the angle of view change speed detected in step S305 increases. This is because when the angle of view change speed is large, the change in photometric value tends to be large as well, and if α is made too small, there is a problem that the tracking performance will be impaired. Alternatively, as an alternative to equation (1), a margin (allowance) may be set so that it does not completely track the target photometric value, or the tracking speed of the photometric value may be made slower compared to when MF operation is not in progress.

[0048] In this way, the amount or rate of change in exposure based on Eb is reduced between Tb and Tc compared to exposure based on Ea. On the other hand, since there is no scene change between Tc and Td, the metering value shown by the solid line Eb is maintained as the target metering value calculated at the angle of view at Tc. After Td, a correction is applied based on the brightness of the object area, and it converges to the same metering value as the dotted line Ea.

[0049] In this way, by suppressing the tracking of the metering value during MF operation, a natural exposure change that is less prone to hunting can be obtained overall. Furthermore, during the period Tb to Tc, the display unit 109 (display means) may notify the user that exposure control is performed using the first metering value without calculating the second metering value, when displaying the live view. For example, this notification may be made by changing the display method (e.g., blinking display) of the frame indicating the focus position, as shown in Figure 1(b), from a solid line display to another display method.

[0050] Returning to Figure 3, in step S309, the camera system control unit 101 determines whether the release button has been pressed. If it has been pressed (YES in step S309), the process proceeds to step S310, where the shooting process is performed, and then the process shown in Figure 3 is terminated. On the other hand, if it has not been pressed (NO in step S309), the process returns to step S302.

[0051] As described above, this embodiment enables natural exposure tracking during manual focus operation in full-time MF mode.

[0052] (Other embodiments) In the above embodiments, the imaging device according to the present invention was described as a personal digital camera, but it is not limited to this. That is, as long as it is equipped with an imaging function and an image synthesis function and has a user interface for setting the exposure time, the imaging device according to the present invention may be a portable device, a smartphone, or a network camera connected to a server. In addition, some of the processing described above may be performed by a portable device, a smartphone, or a network camera connected to a server.

[0053] The present invention can also be realized by supplying a program that implements one or more of the functions of this embodiment to a system or device via a network or recording medium, and by having one or more processors in the computer of that system or device read and operate the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0054] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention.

[0055] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist.

[0056] This embodiment includes the following configurations, methods, and programs. (Configuration 1) An imaging device comprising: an imaging means for capturing an image via an optical system; a setting means for setting the device to a mode that accepts user operation to change the focus position while autofocus is being performed; a calculation means for calculating a first photometric value based on the brightness of a first region of the captured image, and a second photometric value based on the brightness of a second region, which is narrower than the first region and corresponds to the focus position at the time of imaging, and the first photometric value; and an adjustment means for adjusting the exposure at the time of shooting, wherein when the mode is set and the imaging means is periodically capturing an image, the adjustment means, when the user is operating to change the focus position, does not cause the calculation means to calculate the second photometric value, but adjusts the exposure using the first photometric value calculated by the calculation means, and when the user is not operating to change the focus position, adjusts the exposure using the second photometric value. (Configuration 2) The imaging device according to Configuration 1, characterized in that when the first photometric value is used, the target photometric value is calculated by correcting the first photometric value so that the amount or rate of change in exposure adjusted by the adjustment means is smaller than when the second photometric value is used. (Configuration 3) The imaging device according to Configuration 2, characterized in that when the first photometric value is used, it does not track up to the target photometric value. (Configuration 4) An imaging device according to any one of Configurations 1 to 3, further comprising a detection means for detecting the angle of view change speed, wherein when the first photometric value is used, the amount of exposure change or the rate of change is set during the period when the user is operating to change the focal position and the angle of view change speed is detected by the detection means. (Configuration 5) The imaging apparatus according to Configuration 1, further comprising object region detection means for detecting an object region corresponding to the focal position during imaging, wherein the brightness of the second region is the brightness of the object region. (Configuration 6) The imaging device according to Configuration 5, characterized in that the object region detection means detects at least the face region of a person as the object region. (Configuration 7) The imaging apparatus according to any one of Configurations 1 to 6, characterized in that when the mode is set by the setting means and the user has not operated the focal position for a certain threshold time or longer, the adjustment means determines that the user is not operating to change the focal position, and otherwise determines that the user is operating to change the focal position. (Configuration 8) The imaging device according to Configuration 4, further comprising control means for controlling a display unit that displays the captured image in live view, wherein the control means displays a frame indicating the focal position on the display unit, and changes the display method of the frame during the period when the user is operating to change the focal position and the detection means has detected the angle of view change speed. (Method 1) An exposure control method for an imaging device, comprising: an imaging step of capturing an image through an optical system; a setting step of setting the device to a mode that accepts user operation to change the focus position while autofocus is being performed; a calculation step of calculating a first photometric value based on the brightness of a first region of the captured image, and a second photometric value based on the brightness of a second region, which is narrower than the first region and corresponds to the focus position at the time of imaging, and the first photometric value; an adjustment step of adjusting the exposure at the time of shooting; and, when the mode is set and an image is periodically captured in the imaging step, during the adjustment step, if the user is operating to change the focus position, the calculation step does not calculate the second photometric value, and the exposure is adjusted using the first photometric value calculated in the calculation step; and when the user is not operating to change the focus position, the exposure is adjusted using the second photometric value. (Program 1) A program for causing a computer to function as one of the means of an imaging device described in any one of Configurations 1 to 8. [Explanation of Symbols]

[0057] 1 Camera 100 Camera Body 101 Camera System Control Unit 102 memory 103 Image sensor 104 Shutter 105 A / D Conversion Unit 106 Image Processing Unit 107 Memory Control Unit 108 D / A Conversion Section 109 Display section 110 TG 111 Release button 112 Operation section 113 Detection unit 114 Photometry section 115 Ranging section 116 Accelerometer 200 Lens Unit 201 Lens System Control Unit 202 Shooting lens group 203 aperture 204 Focus Ring 300 recording media

Claims

1. An imaging means for capturing an image via an optical system, A setting means for setting the system to a mode that accepts user input to change the focus position while autofocus is running, A calculation means for calculating a first photometric value based on the brightness of a first region of the captured image, and a second photometric value based on the brightness of a second region, which is narrower than the first region and corresponds to the focal position at the time of imaging, and the first photometric value. A means of adjusting the exposure during shooting, It has, When the mode described above is set and images are being captured periodically by the imaging means, the adjustment means: If the user is in the process of changing the focus position, the calculation means will not calculate the second photometric value, and the exposure will be adjusted using the first photometric value calculated by the calculation means. An imaging device characterized by adjusting the exposure using the second photometric value when the user is not performing an operation to change the focal position.

2. The imaging apparatus according to claim 1, characterized in that, when using the first photometric value, the target photometric value is calculated by correcting the first photometric value such that the amount or rate of change in exposure adjusted by the adjustment means is smaller than when using the second photometric value.

3. The imaging device according to claim 2, characterized in that, when using the first photometric value, it does not track up to the target photometric value.

4. It further includes a detection means for detecting the angle of view change speed, The imaging device according to claim 1, characterized in that, when using the first photometric value, the amount or speed of exposure change is set during the period when the user is operating to change the focal position and the angle of view change speed is detected by the detection means.

5. The imaging apparatus according to claim 1, further comprising object region detection means for detecting an object region corresponding to the focal position during imaging, wherein the brightness of the second region is the brightness of the object region.

6. The imaging apparatus according to claim 5, characterized in that the object region detection means detects at least the face region of a person as the object region.

7. The adjustment means is used when the mode is set by the setting means, If the user has not manipulated the focus position for a certain threshold time or longer, it is determined that the user is not currently performing an operation to change the focus position. The imaging device according to claim 1, characterized in that, in other cases, it is determined that the user is in the process of changing the focal position.

8. The system further includes control means for controlling a display unit that displays the captured image in live view, The control means displays a frame indicating the focal position on the display unit. The imaging apparatus according to claim 4, characterized in that the method of displaying the frame is changed during the period in which the user is performing an operation to change the focal position and the angle of view change speed is detected by the detection means.

9. An imaging step in which an image is captured via an optical system, A setting step to configure the system to accept user input to change the focus position while autofocus is running, A calculation step for calculating a first photometric value based on the brightness of a first region of the captured image, and a second photometric value based on the brightness of a second region, which is narrower than the first region and corresponds to the focal position at the time of imaging, and the first photometric value. Adjustment steps to adjust the exposure during shooting, When the above mode is set and images are periodically captured in the imaging step, in the adjustment step, If the user is in the process of changing the focus position, the calculation step will not calculate the second photometric value, and the exposure will be adjusted using the first photometric value calculated in the calculation step. An exposure control method for an imaging device, characterized in that, when the user is not performing an operation to change the focus position, the exposure is adjusted using the second photometric value.

10. A program for causing a computer to function as each of the means of the imaging apparatus described in claim 1.

Images