Imaging apparatus

Abstract

To solve the problem that a brightness of a subject is changed, and a brightness of a screen of a live view image is changed by a frequent driving of an iris.SOLUTION: An imaging apparatus comprises: an imaging element that images an image of a subject formed by an optical system with an iris and outputs a signal; a display part that displays the image generated on the basis of the signal; an operation part that instructs an imaging by the imaging element by an operation; a calculation part that calculates a first iris value as a value of the iris of a photographing on the basis of the operation of the operation part on the basis of the signal; and a control part that sets the first iris value and a second iris value as an iris value of the photographing for displaying a through image that displays the image on the basis of the signal repeatedly imaged by the imaging element to the display part. The control part sets the second iris value so that a frequency that the second iris value is changed becomes smaller than a frequency that the first iris value is changed in accordance with a change of a brightness of the subject.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an imaging device. [Background technology]

[0002] There is known a camera that displays an image for a monitor called a live view image. When the brightness of the subject changes, the aperture of the photographing lens is frequently driven for exposure correction (see Patent Document 1). Therefore, there is a problem that the brightness of the screen of the live view image changes due to the frequent driving of the aperture. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-33061 Summary of the Invention

[0004] According to one aspect of the present invention, an imaging device includes an imaging element that captures an image of a subject formed by an optical system having an aperture and outputs a signal, a display unit that displays an image generated based on the signal, an operation unit that instructs imaging by the imaging element through operation, a calculation unit that calculates a first aperture value which is the aperture value for shooting based on operation of the operation unit based on the signal, and a control unit that sets the first aperture value and a second aperture value which is the aperture value for shooting for displaying on the display unit the image based on the signal repeatedly captured by the imaging element, wherein the control unit sets the second aperture value so that the second aperture value is changed less frequently than the first aperture value in response to changes in brightness of the subject. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a perspective view illustrating a camera system. [Diagram 2] FIG. 2 is a block diagram illustrating a configuration of a main part of the camera in FIG. [Diagram 3] 3(a) to 3(d) are diagrams illustrating the first aperture value and the second aperture value. [Figure 4] FIGS. 4(a) to 4(d) are diagrams illustrating the first aperture value and the second aperture value. [Diagram 5] 5(a) to 5(c) are diagrams illustrating the first aperture value and the second aperture value. [Figure 6] 11 is a flowchart illustrating an example of processing executed by a body side control unit in a live view mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Hereinafter, an embodiment of the invention will be described with reference to the drawings. 1 is a perspective view of a camera system 1 before an interchangeable lens 3 is attached to a camera body 2 according to an embodiment of the invention. The camera body 2 and interchangeable lens 3 are coupled together by a bayonet structure of a body-side mount 210 and a lens-side mount 310. When the camera body 2 and interchangeable lens 3 are coupled together, terminals provided on each mount come into physical contact with each other, electrically connecting the camera body 2 and the interchangeable lens 3. As will be described later using FIG. 2, the camera body 2 is equipped with an operation member 280 such as a release button, and an image sensor 260. FIG. 1 illustrates an example of a lens-interchangeable camera system 1, but the camera system 1 may also be a camera or video camera in which the camera body and lens are integrated.

[0007] FIG. 2 is a block diagram illustrating the configuration of a main part of the camera system 1 according to the first embodiment. <Interchangeable lenses> The interchangeable lens 3 has a lens mount 310 , a lens control unit 330 , a lens communication unit 340 , a lens storage unit 350 , a photographing lens 360 , a lens driving unit 370 , and an aperture driving unit 380 .

[0008] The annular lens side mount 310 is provided with a lens side terminal holding section 320. The lens side terminal holding section 320 has a plurality of lens side terminals arranged in an arc shape centered on the optical axis O. The plurality of lens side terminals include, for example, an attachment detection terminal that informs the camera body 2 that the interchangeable lens 3 is attached to the camera body 2, a plurality of communication terminals used in communication between the interchangeable lens 3 and the camera body 2, a power supply terminal through which power is supplied from the camera body 2 to the interchangeable lens 3, and a ground terminal.

[0009] The lens side control unit 330 is composed of a microcomputer and its peripheral circuits, etc. The lens side control unit 330 executes a control program stored in the lens side storage unit 350 to control each unit of the interchangeable lens 3. The lens side control unit 330 is connected to the lens side communication unit 340, the lens side storage unit 350, the lens driving unit 370, and the aperture driving unit 380.

[0010] The lens side communication unit 340 performs predetermined communication with the body side communication unit 240 in a state in which the interchangeable lens 3 is attached to the camera body 2. The lens side communication unit 340 is connected to the lens side control unit 330 and the above-mentioned lens side terminal. Through communication between the lens side communication unit 340 and the body side communication unit 240 via the contacting lens side terminal and body side terminal, the lens control unit 330 issues instructions such as movement of a lens 361, which will be described later. In addition, a transmission request is sent from the camera body 2 to the lens control unit 330 of the interchangeable lens 3 to transmit information within the interchangeable lens 3, such as information indicating the state of the lens driving unit 370, to the camera body 2.

[0011] The information indicating the state of the lens driving unit 370 is, for example, information indicating a state in which the lens driving unit 370 is driving the lens 361. Meanwhile, data indicating the position of the lens 361 after movement, the state of the driving unit in the interchangeable lens 3, data read from the lens-side storage unit 350, information relating to the shooting distance and shooting magnification, etc. are transmitted to the camera body 2 as information within the interchangeable lens 3.

[0012] The lens-side storage unit 350 is configured with a non-volatile storage medium. The lens-side storage unit 350 has data recording and reading controlled by the lens-side control unit 330. In addition to storing the control program executed by the lens-side control unit 330, the lens-side storage unit 350 stores data indicating the model name of the interchangeable lens 3 (also referred to as model name information) and data indicating optical characteristics such as the focal length and aberration information of the photographing lens 360. The data stored in the lens storage unit 350 may include an error allowance based on the difference in optical characteristics between the first aperture value and the second aperture value, which will be described in detail later.

[0013] The photographing lens 360 guides subject light to the imaging surface of the image sensor 260 of the camera body 2. The optical axis O of the photographing lens 360 coincides with the center of the lens side mount 310 and the body side mount 210. The photographing lens 360 is composed of multiple lenses 361 including a focusing lens and a zoom lens, and an aperture 362. Note that the lens 361 has multiple lenses, but is illustrated in FIG. 2 as a single lens for simplification. At least a part of the photographing lens 360 is configured to be movable forward and backward along the optical axis O by the lens driving unit 370 or by manual operation. For example, the focusing lens is configured to be movable forward and backward in the direction of the optical axis O by a lens driving unit 370. By moving the focusing lens, the focal position of the photographing lens 360 is adjusted.

[0014] The diaphragm 362 is a so-called aperture diaphragm having multiple diaphragm blades, and adjusts the amount of light incident on the image sensor 260 by changing the aperture diameter (aperture value) of the photographing lens 360 by driving the diaphragm blades. The diaphragm drive unit 380 drives the diaphragm blades to change the aperture diameter (aperture value). The diaphragm drive unit 380 is composed of a stepping motor and an diaphragm drive mechanism. The diaphragm drive unit 380 drives the diaphragm blades of the diaphragm 362 to change the aperture diameter based on instructions from the lens side control unit 330. The diaphragm drive unit 380 also detects the aperture value of the diaphragm 362 by measuring the drive amount of the diaphragm blades using an encoder or a pulse counter provided near the diaphragm blades.

[0015] The lens driving unit 370 is configured with a lens driving mechanism including a stepping motor. The lens driving unit 370 moves the focusing lens constituting the lens 361 along the direction of the optical axis O in response to a driving signal output from the lens side control unit 330. The moving direction, moving amount, moving speed, etc. of the focusing lens are instructed by, for example, the body side control unit 230. The lens driving unit 370 detects the position of the focusing lens by an encoder provided near the lens or the driving steps of the stepping motor, etc.

[0016] <Camera body> The camera body 2 has a body mount 210, a body control unit 230, a body communication unit 240, a power supply unit 250, an image sensor 260, a signal processing unit 270, an operation member 280, and a display unit 290. In addition, the recording unit 100 is configured to be detachable from the camera body 2.

[0017] The annular body-side mount 210 is provided with a body-side terminal holder 220. The body-side terminal holder 220 has a plurality of body-side terminals. The plurality of body-side terminals include, for example, an attachment detection terminal that reports that the interchangeable lens 3 is attached, a plurality of communication terminals used for communication between the camera body 2 and the interchangeable lens 3, a power supply terminal through which power is supplied from the camera body 2 to the interchangeable lens 3, and a ground terminal.

[0018] The body side control unit 230 has a storage unit 235 and is composed of a microcomputer and its peripheral circuits, etc. The body side control unit 230 executes a control program stored in the storage unit 235 to control each unit in the camera body 2. The body side control unit 230 is connected to the body side communication unit 240, the power supply unit 250, the image sensor 260, the signal processing unit 270, the operation member 280, the display unit 290, the recording unit 100, and the above-mentioned attachment detection terminal.

[0019] The recording and reading of data in a storage unit 235 provided in the body side control unit 230 is controlled by the body side control unit 230. The storage unit 235 stores the control programs and the like executed by the body side control unit 230, and can also store model name information of the interchangeable lens 3 received by the body side communication unit 240, data indicating the optical characteristics of the interchangeable lens 3, and the like.

[0020] The body side communication unit 240 performs the above-mentioned communication with the lens side communication unit 340 in a state in which the interchangeable lens 3 is attached to the camera body 2. The body side communication unit 240 is connected to the body side control unit 230 and the above-mentioned communication terminal. The power supply unit 250 converts the voltage of a battery (not shown) into a voltage used by each part of the camera system 1, and supplies it to each part of the camera body 2 and the interchangeable lens 3. The power supply unit 250 can switch power supply on and off for each power supply destination according to instructions from the body side control unit 230. The power supply unit 250 is connected to the body side control unit 230 and the above-mentioned power supply terminal.

[0021] The image sensor 260 is a solid-state image sensor, such as a CMOS image sensor or a CCD image sensor, in which pixels are arranged two-dimensionally in the row and column directions. The image sensor 260 captures a subject image on an imaging surface and outputs an image signal in response to a control signal from the body side control unit 230. The image sensor 260 is connected to the body side control unit 230 and the signal processing unit 270.

[0022] The image sensor 260 has pixels for generating an image (referred to as imaging pixels) and pixels for focus detection (referred to as focus detection pixels) arranged on an imaging surface. Signals generated by the imaging pixels (hereinafter referred to as imaging pixel signals) are used to generate image data by a signal processing unit 270, which will be described later. Signals generated by the focus detection pixels (hereinafter referred to as focus detection pixel signals) are used by the signal processing unit 270, which will be described later, for focus detection processing that detects the imaging state of an image formed by the interchangeable lens 3 on the imaging surface of the image sensor 260, in other words, the defocus amount, which will be described later. Note that the image sensor 260 may be configured to include pixels that have a plurality of photoelectric conversion units and output signals that can be used for both imaging and focus detection.

[0023] The signal processing unit 270 generates image data by performing a predetermined image processing on the imaging pixel signals output from the imaging pixels of the imaging element 260. The generated image data is recorded in a predetermined file format in the recording unit 100, or is used for image display by the display unit 290. The signal processing unit 270 is connected to the body side control unit 230, the imaging element 260, and the display unit 290.

[0024] Furthermore, the signal processing unit 270 calculates the defocus amount of the interchangeable lens 3 by a phase difference detection method using focus detection pixel signals output from focus detection pixels of the image sensor 260. The defocus amount is the amount of deviation between the position (imaging plane) of the image of the subject formed by the interchangeable lens 3 and the imaging plane position of the image sensor 260. Based on the calculated defocus amount, the signal processing unit 270 calculates the movement amount of the focusing lens to a focused position, which is the position of the focusing lens when an image of a specific subject is formed on the imaging plane of the image sensor 260 by the interchangeable lens 3.

[0025] The body side control unit 230 also functions as a photometry calculation unit. The body side control unit 230 detects brightness information (Bv value) of the subject based on the imaging pixel signal input from the imaging element 260 to the signal processing unit 270. The body side control unit 230 determines the aperture value (Av value), shutter speed (Tv value), and shooting sensitivity (Sv value) based on the Bv value and information on the program diagram stored in the storage unit 235. The shooting sensitivity is also called ISO sensitivity, and is the gain at the time of photoelectric conversion in the imaging element 260. The Av value, Tv value, and Sv value are values ​​calculated by APEX calculation according to the shooting mode.

[0026] The recording unit 100 is a memory card, which is a non-volatile storage medium. The recording unit 100 is attached to an insertion section (not shown) provided on the inside of the exterior surface of the camera body 2. The recording and reading of image data in the recording unit 100 is controlled by a body side control section 230.

[0027] An operation member 280 including a release button and various operation switches is provided on the exterior surface of the camera body 2. A user operates the operation member 280 to set the shooting mode and the like, as well as to set a live view mode, which will be described later. The shooting mode setting refers to settings such as whether the image to be captured is a still image or a video image, whether the above-mentioned Av, Tv and Sv values ​​are all automatically determined by the camera, or whether some or all of the above-mentioned Av, Tv and Sv values ​​are determined by the user. The release button has two pressing operations: a half press and a full press. When the button is fully pressed, an instruction to capture an image is given to the body side control unit 230, and an image captured by the image sensor 260 and generated by the signal processing unit 270 is stored in the recording unit 100. A half press is a press down operation to about half the amount of depression when the button is fully pressed, and a shooting preparation operation is performed.

[0028] The display unit 290 includes, for example, an organic EL or liquid crystal display panel. The display unit 290 displays an image based on image data processed by the signal processing unit 270, an operation menu screen, and the like, in response to an instruction from the body side control unit 230. The display unit 290 is connected to the body side control unit 230 and the signal processing unit 270. The display unit 290 can also dynamically and sequentially display image data based on signals captured repeatedly by the image sensor 260, a so-called live view image display. This live view image display may have a lower image quality than an image generated by capturing an image by fully pressing the release button. The live view image display is performed when the camera system 1 is powered on in a shooting mode other than the playback mode or the setting mode. In this embodiment, there are three live view modes for displaying live view images, as shown below, and any one of the live view modes can be selected.

[0029] The first live view mode is a mode in which a live view image is displayed with an emphasis on visibility of the displayed image without reflecting various settings set by the user at the time of shooting. The first live view mode is a mode in which a live view image is generated and an exposure calculation is performed based on the image capture pixel signal, and a focus detection process is performed based on the focus detection pixel signal. The various settings during shooting by the user are settings such as shutter speed, aperture value, and exposure to obtain the image effect desired by the user. When the aperture value is set large (the aperture opening is narrowed), the first live view mode displays a bright image in order to emphasize the visibility of the live view image without narrowing the aperture to the set aperture value. In other words, in the first live view mode, the aperture is narrowed only to a predetermined value (a live view aperture value, which is a second aperture value described later) that allows accurate distance measurement calculation from the imaging signal that generates the live view image. This first live view mode is a mode in which the live view image is displayed as close as possible to an optical finder (so-called OVF). Therefore, in the first live view mode, even if the user sets exposure compensation, the live view image is displayed without considering the exposure compensation set by the user. More specifically, even if the user sets exposure compensation of -1 / 3 stops, the image displayed in the live view mode will not be a dark image.

[0030] The second live view mode is a display of a live view image that reflects various settings at the time of actual shooting set by the user. As with the first live view mode, this mode performs generation of a live view image and exposure calculation based on the image capture pixel signal, and performs focus detection processing based on the focus detection pixel signal. In the second live view mode, the exposure at the time of actual shooting is simulated based on the settings at the time of actual shooting, and an image is displayed on the display unit 290. However, in order to enable distance measurement calculation from the image capture signal that generated the live view image, the aperture value is narrowed down to a predetermined value at which distance measurement is possible (a live view aperture value that is a second aperture value that will be described later). The image displayed as the live view image is made dark by image processing. As described above, the first live view mode does not necessarily reflect the user's settings, but in the second live view mode, for example, if the user sets exposure compensation, the live view image is displayed reflecting the exposure compensation set by the user. More specifically, if the user sets exposure compensation of -1 / 3 stops, the image displayed as live view is 1 / 3 stops darker.

[0031] The third live view mode is a mode in which all user-specified shooting settings are reflected in the displayed live view image. In the third live view mode, various calculations for actual shooting are not performed. In the third live view mode, if a large aperture value is set for actual shooting, the aperture value is narrowed down to the set aperture value for shooting. Therefore, the image displayed in live view becomes dark, but the depth of field of the set aperture value can be confirmed, and the actual shooting can be previewed.

[0032] In this embodiment, when the live view mode is either the first or second live view mode in the above-mentioned camera system 1, a live view image is displayed on the display unit 290, and the body side control unit 230 performs exposure calculation and defocus amount calculation based on the image pickup pixel signal and the focus detection pixel signal. This exposure calculation and defocus amount calculation are repeatedly performed during the live view display. The calculated exposure calculation result is used for various settings for subsequent image pickup for the live view image and shooting by pressing the release button. The defocus amount calculated during the display of the live view image is used to instruct the driving of the focusing lens when the release button is half-pressed. The following describes a case where the aperture value at the time of shooting is automatically determined by the body side control unit 230 from the exposure calculation result by the setting of the operation unit. That is, the program automatic exposure calculation mode, the shutter speed priority exposure calculation mode, or the full auto mode in which the sensitivity setting is also calculated is set as the shooting mode.

[0033] <Two aperture values> The body side control unit 230 sets two aperture values. The first aperture value is the first aperture value (also called the aperture value for shooting) that is applied when the release button constituting the operation member 280 is pressed (fully pressed) and image capturing (main shooting) is performed, and is a value based on the APEX exposure calculation described above.

[0034] The second aperture value, which will be described in detail later using Figures 3 to 5, is a second aperture value (also called a live view aperture value) that is applied when capturing an image to display a live view image on the display unit 290, that is, for exposure calculation and calculation of the defocus amount. It is better that the second aperture value is smaller (more open) than the first aperture value. This is because the focal depth (permissible range of distance measurement) of the subject image changes when the aperture value of the aperture 362 of the photographing lens 360 changes. When the aperture value of the aperture 362 is small (open), the focal depth is shallow, and when the aperture value is large (narrowed), the focal depth is deep. For this reason, if the defocus amount is calculated with an aperture value (narrowed) larger than the aperture value set for the actual photographing, an accurate value cannot be calculated. Also, since the best image plane caused by the aberration of the photographing lens 360 changes depending on the aperture value, it is better that the aperture value (second aperture value) when calculating the defocus amount is the same as the aperture value (first aperture value) when photographing. The first aperture value changes through exposure calculation in accordance with changes in the brightness of the subject. However, if the brightness of the subject changes frequently, and the second aperture value during live view display is frequently changed in accordance with changes in the first aperture value to drive the aperture blades, the sound (driving sound) emitted by the aperture drive unit 380 can easily become a problem. In addition, flickering of the live view image due to a sudden change in the brightness of the image displayed on the display unit 290 can also easily become a problem.

[0035] In the live view mode, the body side control unit 230 according to this embodiment calculates control values ​​including the first aperture value based on the photometry value, and stores the calculated values ​​in the storage unit 235. When the release button is fully pressed, the body side control unit 230 instructs the aperture drive unit 380 to drive the aperture 362 to the first aperture value stored in the storage unit 235, and performs shooting to obtain an image for recording.

[0036] Furthermore, in this embodiment, even if the brightness of the subject changes frequently, the body side control unit 230 calculates a second aperture value that changes less than the first aperture value so that the aperture 362 is not driven frequently when capturing a live view image. During live view display, the aperture 362 is driven to the second aperture value to capture a live view image.

[0037] When the body side control unit 230 acquires a live view image, it recalculates control values ​​including the first aperture value based on the new photometric value, and updates and stores the calculated values ​​in the storage unit 235. The body side control unit 230 also recalculates the second aperture value, and updates and stores the calculated value in the storage unit 235. If the release button is not pressed (fully pressed), the body side control unit 230 drives the aperture 362 so that the aperture value of the aperture 362 becomes the second aperture value stored in the storage unit 235, and acquires a live view image.

[0038] <Calculation of the first and second aperture values> The calculation of the first and second aperture values ​​in the live view mode will now be described in further detail. 3(a) to (d) are diagrams for explaining the first aperture value and the second aperture value. The upper line indicates the first aperture value (apex aperture value), and the lower line indicates the second aperture value (live view aperture value). The units of the first aperture value and the second aperture value are exposure calculation values ​​(apex calculation values), with the maximum aperture value being Av1 and the minimum aperture value being Av6. The maximum aperture value and minimum value of the aperture 362 may be changed as appropriate for each model of the interchangeable lens 3, for example. The first aperture value and the second aperture value calculated by the body side control unit 230 are represented by the position of a triangle (▽) on each line. In the example of FIG. 3(a), the calculated first aperture value (aperture value for shooting) is Av4, and the calculated second aperture value (aperture value for live view) is Av3.5.

[0039] The body side control unit 230 controls the accumulation of the image sensor 260 in synchronization with, for example, the frame rate of the live view display. Then, as described above, the Bv value is calculated based on the signal value (also called the photometric value) of the image sensor pixel signal generated by the image sensor pixel of the image sensor 260 through accumulation. Then, based on the Bv value and the information of the program diagram stored in the storage unit 235, the first aperture value (Av value), shutter speed (Tv value), and sensitivity (Sv value) are determined. The first aperture value (Av value), shutter speed (Tv value), and sensitivity (Sv value) are stored in the storage unit 235 as control values. The body side control unit 230 calculates control values ​​including this first aperture value (Av value) each time an imaging pixel signal of the image sensor 260 is input to the signal processing unit 270, and updates and records the calculated control values ​​in the memory unit 235.

[0040] When the body side control unit 230 calculates the initial first aperture value (Av value) in the live view mode, it sets, for example, an allowable range of one step of APEX value (shown by a dashed rectangle) on the open side of the first aperture value (Av value). As described above, the control unit 230 calculates the defocus amount based on the focus detection pixel signal of the live view image, and therefore sets an aperture value with a shallower focal depth of the subject image than the first aperture value set for shooting as the second aperture value. In this embodiment, the range between the first aperture value itself and one step opener than the first aperture value is set as the range for setting the second aperture value, and this is called the allowable range. Then, the initial second aperture value (Av value) is determined to be the intermediate value of the allowable range (1 / 2 stop from the open side). In the example of FIG. 3(a), the first aperture value (aperture value for shooting) is Av4, so the second aperture value (aperture value for live view) is determined to be Av3.5, which is the intermediate value between Av4 and Av3, which is one stop more open. Although the allowable range is exemplified as one step on the open side in the apex value, it is not limited to one step, and may be two steps or 0.5 steps on the open side. Alternatively, the upper limit (smaller diameter side) and lower limit (open side) of the allowable range may be made different depending on the information of the interchangeable lens 3 (focal length, open aperture value, etc.). In addition, an example will be described in which the midpoint of the allowable range is determined as the second aperture value (Av value); however, a value that is not exactly the midpoint of the range (for example, 1 / 3 stop or 5 / 6 stop from the maximum aperture) may also be used as the second aperture value (Av value).

[0041] Fig. 3(b) is a diagram for explaining the first aperture value and the second aperture value when the brightness of the subject becomes brighter than in the state of Fig. 3(a). As explained in Fig. 3(a), the body side control unit 230 determines the first aperture value (Av value).

[0042] In the state of FIG. 3(b), the first aperture value (aperture value for shooting) is changed to the smaller diameter side (larger Av value) than in the state of FIG. 3(a), and the first aperture value is Av4.4, and accordingly, the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the smaller diameter side. The body side control unit 230 determines whether the second aperture value (Av value) determined last time in the state of FIG. 3(a) is included in the allowable range based on the first aperture value calculated this time (shown by the dashed rectangle in FIG. 3(b)). Since Av3.5 set last time (FIG. 3(a)) is within the allowable range (Av3.4 to 4.4) of one step this time, the second aperture value (Av value) in FIG. 3(a) is not changed and is maintained as Av3.5. By maintaining the second aperture value (Av value), the frequency of driving the aperture 362 in live view mode can be reduced.

[0043] Fig. 3(c) is a diagram for explaining the first aperture value and the second aperture value when the brightness of the subject becomes brighter than in the state of Fig. 3(b). The body side control unit 230 determines the first aperture value (Av value).

[0044] In the state of FIG. 3(c), the first aperture value (Av value) is changed to the smaller diameter side than in the state of FIG. 3(b), the first aperture value is Av4.8, and the allowable range of the second aperture value based on the first aperture value (shown by a dashed rectangle) also moves to the smaller diameter side. The body side control unit 230 changes the second aperture value (Av value) to the smaller diameter side because the second aperture value (Av3.5 shown by a dashed triangle in FIG. 3(a)) that is being maintained is out of the allowable range of the second aperture value based on the currently calculated first aperture value (Av4.8) (Av3.8 to 4.8 shown by a dashed rectangle in FIG. 3(c)). The second aperture value (Av value) is determined to be Av4.3 (shown by a solid triangle), which is the intermediate value of the allowable range (Av3.8 to 4.8) of the currently calculated second aperture value.

[0045] Fig. 3(d) is a diagram for explaining the first aperture value and the second aperture value when the brightness of the subject becomes even brighter than in the state of Fig. 3(c). The body side control unit 230 determines the first aperture value (Av value).

[0046] In the state of Fig. 3(d), the first aperture value (Av value) is changed to the smaller diameter side than in the state of Fig. 3(c), the first aperture value is Av5.8, and the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the smaller diameter side. Since the second aperture value (Av value) of Fig. 3(c) determined in the previous calculation falls outside the allowable range of the second aperture value based on the currently calculated first aperture value (Av4.8) (shown by the dashed rectangle in Fig. 3(d)) Av4.8 to 5.8, the body side control unit 230 changes the second aperture value (Av value) to the smaller diameter side and tries to determine the intermediate value of the newly hypothetical range as the second aperture value (Av value).

[0047] However, in this embodiment, the smaller diameter side of the second aperture value (Av value) is limited to Av5. The reason why a limit value is set on the smaller diameter side of the second aperture value (Av value) is that the smaller the opening diameter of the aperture 362, the lower the detection accuracy of the above-mentioned image shift amount (phase difference). Since a decrease in the detection accuracy of the phase difference leads to a decrease in the focus detection accuracy, in this embodiment, a limit value (Av value) is set on the smaller diameter side of the second aperture value (Av value) (Av5 in this example), thereby suppressing a decrease in the focus detection accuracy in live view mode. Therefore, in Figure 3(d), where the subject is even brighter than in Figure 3(c), the permissible range of the second aperture value is Av4.8 to 5.8, as shown in the dashed rectangle, with the midpoint Av5.3, but the second aperture value actually set will be the smaller limit value Av5, as shown by the black triangle (▼). The limit value on the small diameter side of the second aperture value (Av value) may be changed as appropriate for each model of the interchangeable lens 3, for example.

[0048] Fig. 4(a) is a diagram for explaining the first aperture value and the second aperture value when the brightness of the subject becomes brighter than in the state of Fig. 3(d). The body side control unit 230 determines the first aperture value (Av value).

[0049] In the state of FIG. 4(a), the first aperture value (Av value) is changed to the smaller diameter side than in the state of FIG. 3(d), the first aperture value is Av6.8, and the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the smaller diameter side. The body side control unit 230 maintains the second aperture value (Av5) at the smaller diameter limit value Av5, even though the second aperture value (Av value) is out of the allowable range of the second aperture value based on the currently calculated first aperture value (shown by the dashed rectangle in FIG. 4(a)) Av5.8 to 6.8. Even if the brightness of the subject becomes brighter than in the state of FIG. 3(d), the second aperture value in FIG. 4(a) remains at the smaller diameter limit value Av5 shown by the black triangle (▼).

[0050] However, if the small diameter side of the second aperture value (Av value) is restricted, there is a risk that the live view image displayed on the display unit 290 will become bright (overexposed state). In the above-mentioned first live view mode, in order to suppress such a change in brightness of the display screen, the body side control unit 230 may shorten the exposure time (accumulation time, Tv value) of the image sensor 260 or lower the sensitivity (Sv value). By such control, it is possible to suppress a change in brightness of the live view image displayed on the display unit 290. As described above, in the first live view mode, the process of suppressing such a change in brightness of the display screen does not reflect the user's settings (exposure compensation, etc.), but in the second live view mode, the exposure time (accumulation time, Tv value) and the sensitivity (Sv value) are determined taking into account the user's settings (exposure compensation, etc.).

[0051] FIG. 4(b) is a diagram illustrating the first aperture value and the second aperture value when the brightness of the subject is darker than in the state of FIG. 4(a).

[0052] In the state of FIG. 4(b), the first aperture value (Av value) is changed to the open side from the state of FIG. 4(a), and the first aperture value is Av6. Accordingly, the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the open side. The body side control unit 230 maintains the second aperture value (Av value) at the limit value Av5 because Av5, which was set and maintained last time in FIG. 4(a), is within the allowable range of the second aperture value based on the first aperture value calculated this time (shown by the dashed rectangle in FIG. 4(b) Av5-6), and the intermediate value Av5.5 of the allowable range is on the smaller diameter side than the limit value (Av5). In FIG. 4(b), the fact that the second aperture value is maintained at the smaller diameter side limit value Av5 is indicated by a filled triangle (▼).

[0053] FIG. 4(c) is a diagram illustrating the first aperture value and the second aperture value when the brightness of the subject becomes darker than in the state of FIG. 4(b).

[0054] In the state of FIG. 4(c), the first aperture value (Av value) is changed to the more open side than in the state of FIG. 4(b), and the first aperture value is Av4.8. Since the first aperture value (Av value) has been changed to the more open side, the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the more open side. When the second aperture value (Av value) in FIG. 4(a) and FIG. 4(b) maintained at the small diameter limit value Av5 shown by the dotted triangle falls outside the allowable range of the second aperture value based on the currently calculated first aperture value (shown by the dashed rectangle in FIG. 4(c)) Av3.8 to 4.8, the body side control unit 230 changes the second aperture value (Av value) to the more open side. In the state of Figure 4(c), the intermediate value Av4.3 (solid triangle in Figure 4(c)) of the allowable range (Av3.8 to 4.8) of the second aperture value based on the currently calculated first aperture value Av5 is determined as the second aperture value (Av value).

[0055] FIG. 4(d) is a diagram illustrating the first aperture value and the second aperture value when the brightness of the subject becomes darker than in the state of FIG. 4(c).

[0056] In the state of FIG. 4(d), the first aperture value (Av value) is changed to Av4.5, which is more open than the state of FIG. 4(c), and the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle in FIG. 4(d)) also moves to the open side. The body side control unit 230 maintains the second aperture value Av4.3 in FIG. 4(c) determined in the previous calculation without changing it, since the second aperture value Av4.3 in FIG. 4(c) determined in the previous calculation is included in the allowable range of the second aperture value based on the currently calculated first aperture value (shown by the dashed rectangle in FIG. 4(d)) Av3.5 to 4.5. By maintaining the second aperture value (Av value), it is possible to reduce the frequency of driving the aperture 362 in the live view mode.

[0057] FIG. 5(a) is a diagram illustrating the first aperture value and the second aperture value when the brightness of the subject becomes darker than in the state of FIG. 4(d).

[0058] In the state of FIG. 5(a), the first aperture value (Av value) is changed to the more open side than in the state of FIG. 4(b), and the first aperture value is Av2.5. If the current second aperture value (Av4.3 indicated by a dashed triangle in FIG. 5(a)) is greater than the calculated first aperture value (Av2.5 in FIG. 5(a)), the body side control unit 230 sets the second aperture value to be smaller than the first aperture value without comparing the current second aperture value (Av value) with the allowable range of the second aperture value based on the first aperture value. As a repetition of the above, in order for the control unit 230 to calculate the defocus amount based on the focus detection pixel signals of the live view image, an aperture value that provides a shallower focal depth of the subject image than the first aperture value set for shooting is set as the second aperture value. Therefore, since the newly calculated first aperture value Av2.5 is located on the more open side than the maintained second aperture value Av4.3, the intermediate value (Av2) of the allowable range (Av1.5 to 2.5) of the second aperture value based on the currently calculated first aperture value is determined as the second aperture value (Av value).

[0059] FIG. 5(b) is a diagram illustrating the first aperture value and the second aperture value when the brightness of the subject becomes darker than in the state of FIG. 5(a).

[0060] In the state of FIG. 5(b), the first aperture value (Av value) is changed to the open side from the state of FIG. 5(a), and the first aperture value is Av2.2. Accordingly, the allowable range of the second aperture value based on the first aperture value (shown by the dashed rectangle) also moves to the open side. Since the second aperture value Av2 in FIG. 5(a) determined in the previous calculation is included in the allowable range Av1.2 to 2.2 of the second aperture value based on the currently calculated first aperture value (shown by the dashed rectangle in FIG. 5(b)), the body side control unit 230 maintains the second aperture value Av2 in FIG. 5(a) determined in the previous calculation without changing it. By maintaining the second aperture value (Av value), it is possible to reduce the frequency of driving the aperture 362 in the live view mode.

[0061] Fig. 5(c) is a diagram for explaining the first and second aperture values ​​when the brightness of the subject becomes darker than in Fig. 5(b). In the state of Fig. 5(c), the first aperture value (Av value) is changed to Av2, which is more open than in the state of Fig. 5(b), and the virtual range (shown by the dashed rectangle) also moves to the open side, becoming Av1-2.

[0062] In this embodiment, the maximum aperture of the aperture 362 is Av2. That is, the maximum aperture of the interchangeable lens 3 is Av2 (F value is 2). When the first aperture value (Av value) calculated based on the Bv value and the information of the program diagram stored in the storage unit 235 is more open than the maximum aperture, the body side control unit 230 maintains the first aperture value (Av value) at the maximum aperture. When the first aperture value (Av value) is set to the maximum aperture, the second aperture value (Av value) is also set to the same maximum aperture as the first aperture value (Av value). In FIG. 5(c), a filled triangle (▼) indicates the maximum aperture.

[0063] As described above, in this embodiment, in order to reduce the frequency of driving the aperture 362 in live view mode, the second aperture value, which is the aperture value for live view, is always set to be more open than the first aperture value, which is the aperture value for shooting, and control is performed so as to minimize changes to the second aperture value (Av value) even if the brightness of the subject changes.

[0064] <Explanation of the flow chart> An example of the processing executed by the body side control unit 230 when the above-mentioned live view mode is either the first or second live view mode will be described with reference to the flowchart in Fig. 6. The body side control unit 230 starts up, for example, when the main switch is turned on, or goes into sleep mode if no operation is performed for a predetermined time, and when the sleep mode is released by operating the operation member 280, the processing according to the flowchart in Fig. 6 is started. The sleep mode is released (returned to the normal state) when a switch or the like constituting the operation member 280 is operated. The operation may be, for example, a half-press operation of the release button. Fig. 6 describes the processing for displaying a live view by turning on the power or releasing the sleep mode, but the live view display is repeated until the release button is fully pressed.

[0065] In step S10, the body side control unit 230 controls the exposure setting in live view mode to a predetermined value (initial value), and performs accumulation control on the image sensor 260. For example, it instructs the interchangeable lens 3 to drive the aperture 362 to a predetermined initial value (corresponding to the above-mentioned second aperture value), controls the accumulation time and sensitivity of the image sensor 260 in imaging for live view to the predetermined initial values, and causes an accumulation operation to be performed for capturing the first live view image.

[0066] In step S20, the body side control unit 230 reads out a signal from the image sensor 260 to the signal processing unit 270, and the process proceeds to step S30. In step S30, the body side control unit 230 performs exposure calculation to calculate the first aperture value (aperture value for shooting) and the second aperture value (aperture value for live view) as described above. That is, the body side control unit 230 detects brightness information (Bv value) of the subject based on the image pixel signal input to the signal processing unit 270, and determines the aperture value for shooting (first aperture value, Av value), shutter speed (Tv value), and sensitivity (Sv value) based on the Bv value and the information of the program diagram stored in the storage unit 235. Furthermore, the body side control unit 230 calculates the allowable range of the second aperture value separately from the first aperture value. Each control value including the allowable range of the calculated first aperture value and second aperture value is stored in the storage unit 235.

[0067] Furthermore, in step S30, the body side control unit 230 also calculates the defocus amount. The body side control unit 230 causes the signal processing unit 270 to calculate the defocus amount as described above, using signals output from the focus detection pixels of the image sensor 260. In this embodiment, the defocus amount is calculated in step S30, but the focusing lens is not yet driven at this point.

[0068] In step S40, the body side control unit 230 sets the aperture 362 to the second aperture value (aperture value for live view) as described with reference to Figures 3 to 5, and then performs live view display. The body side control unit 230 causes the signal processing unit 270 to generate a live view image using the imaging pixel signals output from the image sensor 260, and causes the display unit 290 to display the generated live view image.

[0069] In step S50, the body side control unit 230 determines whether or not the release button has been pressed halfway. If the release button has been pressed halfway, the body side control unit 230 makes an affirmative judgment in step S50 and proceeds to step S60, and if the release button has not been pressed halfway, the process returns to step S10.

[0070] In step S60, based on the defocus amount calculated by the signal processing unit 270 in step S30, the body side control unit 230 moves the focusing lens that constitutes the lens 361 relative to the interchangeable lens 3 along the direction of the optical axis O. That is, the lens side control unit 330 issues an instruction to the lens driving unit 370 to drive the focusing lens, and a focusing drive operation is performed. Then, the process proceeds to step S70.

[0071] In step S70, the body side control unit 230 determines whether or not the release button has been fully pressed. If the release button has been fully pressed, the body side control unit 230 makes an affirmative decision in step S70 and proceeds to step S80, and if the release button has not been fully pressed, the body side control unit 230 makes a negative decision in step S70 and returns to step S10.

[0072] After returning to step S10, the body side control unit 230 again performs the processes from step S10 onwards. The exposure settings for the second and subsequent frames in live view mode use the second aperture value stored in the storage unit 235, and the shutter speed (Tv value) and sensitivity (Sv value) stored in the storage unit 235. Here, at least one of the shutter speed (Tv value) and sensitivity (Sv value) stored in the storage unit 235 may be corrected. The reason for this is that, as described above, there are cases in which the brightness of the live view image displayed on the display unit 290 changes in accordance with changes in the brightness of the subject, so the brightness of the live view image displayed is adjusted by correcting the shutter speed (Tv value) and / or sensitivity (Sv value).

[0073] In step S80, which is the step to be taken if the release button is fully pressed (YES in step S70), the body side control unit 230 performs a storage operation for capturing an image for recording. At that time, the aperture 362 stored in the storage unit 235 is set to a first aperture value (aperture value for shooting, Av value), storage control of the image sensor 260 is performed at the shutter speed (Tv value) calculated by APEX calculation and stored in the storage unit 235, and sensitivity (Sv value) processing is performed, which is also calculated by APEX calculation and stored in the storage unit 235.

[0074] In step S90, the body side control unit 230 reads out signals from the image sensor 260 to the signal processing unit 270, and proceeds to step S100. In step S100, the body side control unit 230 causes the signal processing unit 270 to perform predetermined image processing on the imaging pixel signals output from the image sensor 260, and generate an image for recording. As a result, the signal processing unit 270 performs the predetermined image processing to generate an image for recording.

[0075] In step S110, the body side control unit 230 performs image display. That is, the body side control unit 230 causes the display unit 290 to display the image processed by the signal processing unit 270 in step S100. In step S120, the body side control unit 230 causes the recording unit 100 to record the file of the image processed by the signal processing unit 270.

[0076] In step S130, the body side control unit 230 determines whether or not the live view mode has ended. If the live view mode has ended, the body side control unit 230 makes an affirmative decision in step S130 and ends the processing in Fig. 6. If the live view mode has not ended, the body side control unit 230 makes a negative decision in step S130 and returns to step S10. Here, the live view mode ends when the power is turned off, a menu is displayed on the display unit 290 by user operation, or the device goes into sleep mode and there is no need to display the live view.

[0077] The display process (S100) and the recording process (S110) in FIG. 6 may be switched in order, or may be performed in parallel. In addition, in this embodiment, the defocus amount is calculated in step S30, and after a half-press operation is performed in step S50, the focusing lens is driven in step S60. However, it is also possible to calculate the defocus amount in step S30 and drive the focusing lens at the same time.

[0078] In either the first or second live view mode of the above-described embodiment, the following advantageous effects can be obtained. (1) A camera system (camera system 1) consisting of a camera body 2 and an interchangeable lens 3 equipped with an aperture 362 includes a body side control unit 230 that calculates a first aperture value, which is an aperture value for shooting, based on a photometric value, and a body side control unit 230 that sets a second aperture value, which is an aperture value for live view, within an aperture value allowable range, based on the first aperture value. With this configuration, even if the brightness of the subject changes and the first aperture value changes, if the second aperture value is set within the aperture value allowable range, the second aperture value that has been set is maintained without immediately changing in conjunction with the changed first aperture value. This prevents the aperture 362 from being frequently driven in live view mode, and reduces the drive noise. In addition, since the frequency of aperture change is reduced, the durability of the lens aperture mechanism can be improved (durable wear can be reduced). Suppressing the drive of the aperture 362 in live view mode is also advantageous in that it suppresses flickering of the screen of the display unit 290 that displays the live view image. Furthermore, this is also suitable for avoiding the hunting phenomenon that occurs during photometry due to repeated driving of the aperture 362.

[0079] (2) The allowable aperture value range of the second aperture value is set based on the first aperture value, so that the aperture value limit range can be set within an appropriate range corresponding to the brightness of the subject.

[0080] (3) The aperture value tolerance range of the above-mentioned second aperture value (aperture value for live view) is always set to the open side more than the first aperture value (aperture value for shooting). In general, the larger the aperture diameter of the aperture 362 (the larger diameter side), the shallower the focal depth of the subject image as described above, and therefore the detection accuracy of the amount of image shift (phase difference) improves. In this embodiment, by setting the aperture value limit range on the side where the aperture diameter of the aperture 362 is larger than the first aperture value (the open side), it is possible to suppress a decrease in the accuracy of phase difference detection and, in turn, the accuracy of focus detection.

[0081] (4) When the brightness of the subject changes and the first aperture value is updated (newly calculated), the body side control unit 230 updates the allowable aperture value range of the second aperture value. Also, if the set (previously calculated) second aperture value is within the updated aperture limit range, the body side control unit 230 does not change the second aperture value. This configuration makes it possible to reduce the frequency of driving the aperture 362 in live view mode.

[0082] (5) When the brightness of the subject changes and the newly calculated first aperture value (aperture value for shooting) is more open than the second aperture value set by the previous calculation result, the body side control unit 230 sets the second aperture value (aperture value for live view) to a value more open than the calculated first aperture value. Then, the aperture allowable range of the second aperture value is updated, and the second aperture value is reset (updated) within the updated aperture limit range. With this configuration, the aperture value limit range is set to a value more open than the first aperture value, and driving of the aperture 362 in live view mode can be suppressed without reducing the accuracy of focus detection accuracy.

[0083] (6) The allowable aperture value range for the second aperture value (aperture value for live view) is set to be more open than the first aperture value (one step more open than the first aperture value in this embodiment). The body side control unit 230 then sets the newly set second aperture value to approximately the center of the allowable aperture value range. Therefore, in this embodiment, unless the brightness information of the subject increases or decreases by 0.5 steps or more in the APEX value, it is not necessary to reset (update) the second aperture value. This configuration makes it possible to appropriately suppress the frequency with which the aperture 362 is driven.

[0084] (7) The body side control unit 230 is configured to change the upper and lower limits of the permissible aperture value range of the second aperture value based on information about the interchangeable lens 3. With this configuration, it is possible to set an appropriate value in accordance with the optical characteristics of the lens 361, for example.

[0085] (8) The information on the interchangeable lens 3 is at least one of the error allowance based on the difference in optical characteristics between the first and second aperture values, the shooting distance, and the shooting magnification. With this configuration, the upper and lower limits of the aperture value limit range can be appropriately set.

[0086] (9) The camera body 2 of the camera system 1 includes a body-side control unit 230 that calculates a first aperture value (aperture value for shooting) and a second aperture value (aperture value for live view) and instructs the interchangeable lens 3 to drive the aperture 362 to the second aperture value. With this configuration, the camera body 2 can perform calculations and send an instruction to the interchangeable lens 3 to drive the aperture 362 to the second aperture value. (10) The body-side control unit 230 may change the aperture value tolerance range of the second aperture value depending on the autofocus mode (for example, a mode in which the focal position is fixed while the shutter button is half-pressed to focus once, or a mode in which the focusing operation is repeated while the shutter button is half-pressed). Note that the aperture may be controlled within the aperture value tolerance range of the second aperture value even in manual mode.

[0087] The following modifications are also within the scope of the present invention, and one or more of the modifications may be combined with the above-described embodiment. (Variation 1) The processing executed by the camera system (camera system 1) of the above-described embodiment may be appropriately shared between a body side control unit 230 on the camera body 2 side and a lens side control unit 330 on the interchangeable lens 3 side. For example, the first and second aperture values ​​may be calculated on the camera body side, and a driving force for driving the aperture 362 on the interchangeable lens side may be transmitted from the camera body to the interchangeable lens. That is, the camera body 2A includes a body side control unit 230 that calculates the first and second aperture values, an actuator that generates power for a drive mechanism of the aperture 362 provided in the interchangeable lens 3A to drive the aperture 362 to the second aperture value, and a transmission member that transmits the power to the interchangeable lens 3A. With this configuration, it is possible to suppress driving of the aperture 362 in live view mode in the camera system.

[0088] (Variation 2) Also, the first and second aperture values ​​may be calculated on the camera body side, and the second aperture value may be transmitted from the camera body to the interchangeable lens. When the interchangeable lens receives the second aperture value, the aperture drive unit 380 drives the aperture 362 to the second aperture value. That is, the interchangeable lens 3B includes a lens side communication unit 340 that receives the second aperture value set by the body side control unit 230 of the camera body 2, an aperture drive unit 380 that drives the aperture 362, and a lens side control unit 330 that instructs the aperture drive unit 380 to drive the aperture 362 to the second aperture value received by the lens side communication unit 340. By configuring in this way, the frequency with which the aperture 362 is driven in live view mode can be appropriately reduced in the camera system.

[0089] In the above, an example has been described in which the lens control unit 330 controls the aperture 362 using an aperture value (Av value) based on the APEX calculation, but the lens control unit 330 may also control the aperture value using a value of the number of stops from the maximum aperture of the interchangeable lens 3.

[0090] (Variation 3) In the camera system (camera system 1) of the embodiment described above, the body side control unit 230 of the camera body 2 calculates two aperture values, the first aperture value and the second aperture value, and transmits the two aperture values, the first aperture value and the second aperture value, to the lens side control unit 330 of the interchangeable lens 3 via the communication unit. However, this is not limiting, and only the first aperture value may be calculated in the body side control unit 230 and only the first aperture value may be transmitted to the lens side control unit 330 via the communication unit. In that case, the lens side control unit 330 autonomously sets the second aperture value. That is, the lens side control unit 330 of the interchangeable lens 3 sets the second aperture value, which is the aperture value for live view, within the permissible aperture value range based on the first aperture value received from the camera body 2. As in the above embodiment, the allowable aperture value range of the second aperture value (aperture value for live view) set by the lens side control unit 330 is always set to be more open than the first aperture value (aperture value for shooting). The lens side control unit 330 of the interchangeable lens 3 then compares the first aperture value transmitted from the camera body 2 with the currently set second aperture value. As in the above embodiment, the lens side control unit 330 is configured to maintain the set second aperture value without immediately changing in conjunction with the received first aperture value, even if the first aperture value received from the camera body 2 has changed, as long as the second aperture value is set within the allowable aperture value range. As in the above-described embodiment, the lens side control unit 330 of the interchangeable lens 3 sets the allowable aperture value range of the second aperture value (aperture value for live view) one stop more open than the first aperture value (aperture value for shooting) and sets the newly set second aperture value approximately in the center of the allowable aperture value range, so that the second aperture value does not need to be reset (updated) unless the brightness information of the subject increases or decreases by 0.5 stops or more in the APEX value. With this configuration, the frequency with which the aperture 362 is driven can be appropriately reduced. Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0091] The disclosures of the following priority applications are incorporated herein by reference: Japan Patent Application No. 2018-135197 (filed July 18, 2018) [Explanation of symbols]

[0092] 1... camera system, 2... camera body, 3... interchangeable lens, 230... body side control unit, 235... storage unit, 240... body side communication unit, 270... signal processing unit, 290... display unit, 330... lens side control unit, 340... lens side communication unit, 350... lens side storage unit, 360... photographing lens, 362... aperture, 370... lens driving unit, 380... aperture driving unit

Claims

1. an image sensor that captures an image of a subject formed by an optical system having an aperture and outputs a signal; a display unit that displays an image generated based on the signal; an operation unit for instructing the imaging device to capture an image by an operation; a calculation unit that calculates a first aperture value, which is an aperture value for photographing based on an operation of the operation unit, based on the signal; a control unit that sets the first aperture value and a second aperture value that is an aperture value for shooting a through image display that displays the image based on the signal repeatedly captured by the image sensor on the display unit; Equipped with the control unit sets the second aperture value such that the second aperture value is changed less frequently than the first aperture value in response to a change in brightness of the subject. Imaging device.

2. when the first aperture value is changed, if the second aperture value is within an allowable range based on the changed first aperture value, the control unit does not change the second aperture value; The imaging device according to claim 1 .

3. the control unit changes the second aperture value when the second aperture value is not within the allowable range when the first aperture value is changed. The imaging device according to claim 2 .

4. The control unit sets the permissible range to a value more open than the first aperture value. The imaging device according to claim 2 or 3.

5. The control unit determines the acceptable range based on information received from the optical system. The imaging device according to claim 2 or 3.

6. the control unit is capable of selectively setting a first through-image display mode and a second through-image display mode, setting the second aperture value so that the second aperture value is changed less frequently than the first aperture value in response to a change in brightness of the subject when the first through-image display mode is set; when the second through-image display mode is set, the second aperture value is set so that a change in the first aperture value is reflected in the second aperture value; The imaging device according to claim 1 .

7. the control unit performs control to change the second aperture value based on the first aperture value and control to not change the second aperture value based on a difference between the first aperture value and the second aperture value. The imaging device according to claim 1 .

8. the control unit performs control to change the second aperture value based on the first aperture value when the first aperture value is larger than the second aperture value and a difference between the first aperture value and the second aperture value is larger than a first value. The imaging device according to claim 7.

9. the control unit performs control not to change the second aperture value when the first aperture value is greater than the second aperture value and a difference between the first aperture value and the second aperture value is equal to or less than a first value. The imaging device according to claim 8.

10. When the first aperture value becomes smaller than the second aperture value, the control unit changes the second aperture value based on the first aperture value. The imaging device according to claim 1 .

11. When the control unit changes the second aperture value based on the first aperture value, the control unit changes the second aperture value to a value smaller than the first aperture value. The imaging device according to claim 10.

12. a detection unit that detects a deviation between a position of the image of the subject and the imaging element based on the signal; having the control unit repeatedly performs the imaging by the imaging element, the calculation of the first aperture value, the display on the display unit, and the detection of the deviation, and when the operation unit is operated, changes the aperture of the optical system to the first aperture value and performs imaging. The imaging device according to claim 1 .

Images