JP2008203428A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a focusing time while preventing defocusing upon photographing. <P>SOLUTION: In the case of detecting the focusing state of a photographing optical system, based on an image signal outputted from an imaging element, and then, focusing the photographing optical system, based on the focus detection result (S9), a diaphragm value upon detecting the focus is set (S5 to S7) in accordance with the diaphragm value (S2) set upon photographing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus.

  An imaging apparatus configured to drive a focusing lens based on a focus detection result when the aperture is in an open state and then re-drive the focusing lens based on a focus detection result in a state where the aperture is reduced to an aperture value for shooting. It is known (see, for example, Patent Document 1).

Prior art documents related to the invention of this application include the following.
JP 2004-109691 A

  In the conventional imaging apparatus described above, since focus adjustment is performed again with the shooting aperture value before shooting, the focus position at the time of focus adjustment matches the focus position at the time of shooting, and the focus shift at the time of shooting is eliminated. However, there is a problem in that it takes time to detect the focus twice and to adjust the focus based on each result every time shooting is performed.

  When detecting the focus adjustment state of the photographic optical system based on the image signal output from the image sensor and performing the focus adjustment of the photographic optical system based on the focus detection result, according to the set aperture value at the time of shooting Set the aperture value for focus detection.

  According to the present invention, it is possible to shorten the focus adjustment time while preventing a focus shift during photographing.

<< First Embodiment of the Invention >>
A first embodiment in which the present invention is applied to a digital single-lens reflex camera equipped with a hybrid AF device of phase difference detection type automatic focus adjustment (hereinafter referred to as AF) and contrast detection type AF will be described. Note that the present invention is not limited to the hybrid AF apparatus of the phase difference detection AF and the contrast detection AF, and can also be applied to a hybrid AF apparatus in which the contrast detection AF and other AFs are combined.

  FIG. 1 shows a configuration of a digital single-lens reflex camera according to the first embodiment. The focus adjustment device of this camera is a hybrid AF device of phase difference detection AF and contrast detection AF. In the camera according to the first embodiment, the lens barrel 20 is attached to the camera body 1. In the first embodiment, an interchangeable lens camera will be described as an example. However, the present invention is not limited to the interchangeable lens camera, and is applicable to a fixed lens camera (lens integrated camera). it can.

  The camera body 1 includes an image sensor 2, a shutter 3, a focus detection optical system 4, an image sensor 5, a focus detection calculation circuit 6, a camera control circuit 7, a drive circuit 8, a quick return mirror 9, a sub mirror 10, a viewfinder screen 11, and a penta. A prism 12, a photometric lens 13, a photometric sensor 14, an eyepiece lens 15, an operation member 16, and the like are provided.

  The imaging device 2 converts the subject image formed by the imaging lens 23 in the lens barrel 20 into an electrical signal and outputs it. When the shutter button (not shown) is fully pressed (during shutter release), the shutter 3 is opened only for the time of the exposure calculation result or the shutter speed manually set by the photographer to expose the image sensor 2 and the shutter button. When it is half-pressed, it is opened to perform contrast detection AF, and the image sensor 2 is exposed. The focus detection optical system 4, the image sensor 5, and the focus detection calculation circuit 6 constitute a phase difference detection type focus detection device, and detect a defocus amount indicating a focus adjustment state of the photographing lens.

  The control circuit 7 includes a microcomputer (not shown) and peripheral components such as a memory, and performs calculation control such as sequence control such as photometry, focus detection, and photographing, exposure calculation, and focus evaluation value calculation in contrast detection AF. The drive circuit 8 controls driving of a lens and an aperture driving actuator 25 provided in the lens barrel 20. The photometric sensor 14 divides the photographing screen into a plurality of areas and outputs a photometric signal corresponding to the luminance of each area.

  The lens barrel 20 includes a focusing lens 21, a zooming lens 22, an aperture 24, a lens and an aperture driving actuator 25, a lens memory 26, and the like. In FIG. 1, the focusing lens 21 and the zooming lens 22 are represented by a single photographing lens 23. The focusing lens 21 is a lens that is driven in the optical axis direction by an actuator 25 to adjust the focus of the photographing lens 23. The zooming lens 22 is a lens that is driven in the optical axis direction by an actuator 25 to change the focal length of the photographing lens 23. The diaphragm 24 is driven by an actuator 25 to change the diaphragm opening diameter. The lens memory 26 stores information related to the photographing optical system, such as the open F value of the photographing lens 23, the focal length, and the aperture threshold value Fk (details will be described later).

  An operation member 16 operated by the photographer is disposed on the camera body 1. The operation member 16 includes a release half-push switch that is turned on when the shutter button is half-pressed, a release full-push switch that is turned on when the shutter button is fully pushed.

  Except during shooting and contrast detection AF, the quick return mirror 9 and the sub mirror 10 are placed in the shooting optical path as shown in FIG. At this time, part of the light from the subject that has passed through the photographing lens 23 is reflected by the quick return mirror 9 and guided to the finder screen 11 to form a subject image on the screen 11. This subject image is guided to the photographer's eyes via the pentaprism 12 and the eyepiece lens 15 and is also guided to the photometric sensor 14 via the pentaprism 12 and the photometric lens 13. The control circuit 7 performs an exposure calculation based on a photometric signal for each photometric area (divided photometric area) output from the photometric sensor 14, and calculates a shutter speed and an aperture value corresponding to the brightness of the shooting screen. . When the manual exposure shooting mode is set, the shutter speed and aperture value set by the photographer operating the operation member 16 are used.

  On the other hand, another part of the light from the subject that has passed through the photographing lens passes through the quick return mirror 9 and is reflected by the sub mirror 10, and is guided to the image sensor 5 through the focus detection optical system 4. In the first embodiment, focus detection areas are set at a plurality of positions in the shooting screen, and the image sensor 5 outputs a focus detection signal indicating the focus adjustment state of the shooting lens 23 for each focus detection area. To do. The focus detection calculation circuit 6 calculates a defocus amount indicating the focus adjustment state of the photographing lens based on the focus detection signal for each focus detection area. The control circuit 7 calculates a lens drive amount based on the defocus amount, and drives the actuator 25 by the drive circuit 8 to drive the focusing lens 21 in focus.

  During photographing and contrast detection AF, the quick return mirror 9 and the sub mirror 10 are retracted from the photographing optical path (mirror up), and the light flux from the subject that has passed through the photographing lens 23 with the shutter 3 opened is guided to the image sensor 2. . During contrast detection AF, the control circuit 7 controls the focus detection area of the image sensor 2 (this area is positioned relative to the focus detection area selected during focus detection using the image sensor 5 (in the imaging frame). The focus position is detected based on the pixel output of the position (corresponding position area), and the driving circuit 8 drives the actuator 25 to drive the focusing lens 21 in focus. Further, at the time of imaging, imaging is performed by the imaging element 2.

  Here, lens driving in contrast detection AF will be described. In the first embodiment, the focusing lens 21 is driven in three stages of initial drive, search drive, and focus drive during contrast detection AF. In the initial driving, the contrast detection method AF is started from the focus position by the phase difference detection method AF. In order to perform the contrast detection method AF within a predetermined range centered on the focus position of the phase difference detection method AF, The focusing lens 21 is moved to a position away from the in-focus position of the phase difference detection AF by a predetermined amount (in the optical axis direction of the lens 21).

  After the initial drive, search drive is started. That is, the focusing lens 21 is moved by a predetermined driving amount (step width), and the focus evaluation value is calculated based on the contrast of the image in the focus detection area focused by the phase difference detection method AF. This operation is repeated until the peak of the focus evaluation value is found. When the peak of the focus evaluation value is found, the peak position is set as the in-focus position. Finally, the focusing lens 21 is moved to the in-focus position and brought into focus in the focus drive.

  In the first embodiment, the same focus detection area is set in the phase difference detection AF and the contrast detection AF, and the photographer can select the focus detection area of the operation member 16 from the plurality of focus detection areas. Either one is selected by the selection switch, or the camera automatically selects one. In the latter automatic selection, for example, a focus detection area showing the closest defocus amount is selected, or a focus detection area showing a defocus amount close to the defocus amount at the previous AF is selected.

  Next, the relationship between the aperture value of the aperture 24 and the focus position of the taking lens 23 will be described. Generally, the focus position changes according to the aperture value due to the influence of spherical aberration of the photographing lens. FIG. 2 is a diagram showing how the focus position changes with respect to the F value of the lens using the zoom lens position as a parameter. Assume that the focus position indicated by A1 is obtained when the contrast detection AF is performed at the zoom lens position A with the aperture opened (F1.4). Next, when the diaphragm is narrowed down to F2 and the contrast detection method AF is performed, the in-focus position indicated by A2 is detected. That is, when the aperture is changed from F1.4 to F2, the in-focus position is shifted by (A2-A1). At the zooming lens position B, when the aperture is changed from F1.4 to F2, the in-focus position is shifted by (B2-B1).

  Normally, the focus of the photographic lens is detected with the aperture open, so that when the focus is adjusted according to the focus detection result of the open aperture, the focus position of the photographic lens matches the light receiving surface (or fill surface) of the image sensor. To do. After performing focus adjustment with the aperture fully open, when shooting with the aperture reduced to the shooting aperture value, the focus position of the photographic lens shifts from the light-receiving surface of the image sensor due to the influence of spherical aberration of the photographic lens, causing focus shift. To do. When the photographic lens is a zoom lens, the image height of the lens changes due to zooming, so the spherical aberration also changes, and the focus position changes depending on the aperture value and the zooming lens position. Similarly, since the image height of the lens also changes due to focusing, the focusing position changes according to the lens position (zooming lens position and focusing lens position) of the stop and the taking lens.

  The relationship between the aperture value and the focus position with respect to the lens position is stored in advance in the camera or in the memory of the lens, and the focus position corresponding to the change in aperture value from the open aperture to the shooting aperture and the lens position at the time of shooting is stored. It is also conceivable to eliminate the focus deviation by reading the change amount and calculating the focus correction amount based on the change amount. However, this is not a good solution because a map must be prepared for each type of photographic lens and a larger memory capacity is required.

  Therefore, in this embodiment, when the aperture value of the exposure calculation result or the aperture value manually set by the photographer, that is, the imaging aperture value F is equal to or smaller than the predetermined threshold value Fk, that is, the imaging aperture value F is opened. When the aperture value is within the range from the aperture value F0 to the threshold value Fk, the contrast detection method AF is not performed with the full aperture value F0, and the contrast detection method AF is performed with the photographing aperture value F as it is. Shooting is performed with the value F. On the other hand, when the photographic aperture value F is larger than the threshold value Fk, that is, when the photographic aperture value F is narrower than the threshold value Fk (when the aperture aperture diameter is small), contrast detection is performed with the open aperture value F0. The system AF is performed, and then the photographing aperture value F is reduced to perform photographing.

  Here, the threshold value Fk is a value that does not cause a focus shift due to the depth of field (depth of focus) of the photographing lens when the aperture value is reduced from the full aperture value F0 to the threshold value Fk. When the contrast detection AF is performed with the aperture stopped down, values that do not cause focus detection failure due to insufficient light amount or abnormally long focus detection time are set for each type of shooting lens. Is obtained by calculation or experiment and is stored in the lens memory 26 or the memory in the camera.

  When the shooting aperture value F is less than or equal to the threshold value Fk, that is, when the shooting aperture value F is within the range from the open aperture value F0 to the threshold value Fk, the contrast detection method AF is performed with the shooting aperture value F. Therefore, the image is taken with the in-focus position at the time of AF, and the problem of in-focus position deviation does not occur. In addition, the photographing aperture is in a fully open state from the full aperture value F0 to the threshold value Fk, and the amount of light used for the contrast detection method AF is large. It is unlikely to be long.

  On the other hand, when the photographing aperture value F is larger than the threshold value Fk, that is, when the photographing aperture value F is narrowed down more than the threshold value Fk, the photographing aperture is performed after performing the contrast detection method AF with the full aperture value F0. Although shooting is performed with the aperture stopped down to the value F, since the shooting aperture value F is relatively large and the depth of field (depth of focus) increases, the in-focus position is reduced by narrowing down from the open aperture value F0 to the shooting aperture value F. Even if is changed, the amount of change in the in-focus position becomes the amount of change within the depth of field, and the out-of-focus state in the photographed image does not appear. In addition, since the contrast detection method AF is performed with the full aperture value F0, it is possible to avoid the focus detection failure and the length of focus detection time due to insufficient light quantity when performing the AF with the large photographing aperture value F narrowed down.

  Note that, when the photographing aperture value F is larger than the threshold value Fk, that is, when the photographing aperture value F is narrower than the threshold value Fk, the contrast detection method AF is performed with the full aperture value F0. The contrast detection method AF may be performed with an aperture value smaller than the photographing aperture value F, or the contrast detection method AF may be performed with an aperture value equal to or less than the threshold value Fk. Even in this way, it is possible to prevent a focus shift in the photographed image even though the photographing aperture value F and the aperture value in the contrast detection method AF are different.

  Further, when determining the aperture value in the contrast detection method AF, the aperture value may be determined based on the subject brightness of the photometric result obtained by the photometric sensor 14. In contrast detection AF, since the object light incident through the aperture opening is received by the image sensor 2 and charges are accumulated, the aperture opening may be any aperture where the charge accumulation time, that is, the focus detection time does not become too long. When the subject brightness is high, the amount of the subject light is sufficiently large for AF detection, so that the aperture opening is made relatively small, that is, focus detection is performed in a short time even if the aperture value is increased during contrast detection AF. On the contrary, when the subject brightness is low, the amount of light of the subject light is small for AF detection, so that the aperture opening is made relatively large, that is, in order to perform focus detection in a short time, contrast detection AF It is necessary to reduce the aperture value at the time. As described above, the optimum aperture value can be determined by determining the aperture value in the contrast detection method AF according to the detected value of the subject brightness.

  FIG. 3 is a flowchart (solid line flow) showing the photographing operation of the first embodiment. This flowchart also describes the operation in the single AF mode (a mode in which once the subject is focused, the driving of the focusing lens 21 is stopped at the focus position). When the control circuit 7 detects that the shutter button is half-pressed by the release half-press switch of the operation member 16 in step 1, the control circuit 7 starts this photographing operation. In step 2, photometry is performed by the photometry sensor 14, and exposure calculation is performed based on the photometry result to determine the shutter speed and the photographing aperture value F. When the manual exposure shooting mode is set, the shutter speed and aperture value F manually set by the photographer are used. In step 3, the defocus amount for each focus detection area is detected by the image sensor 5 and the focus detection calculation circuit 6, and the defocus amount of the focus detection area selected by the photographer or the focus detection area automatically selected by the camera. Accordingly, the focusing lens 21 is driven and focused by the drive circuit 8 and the actuator 25.

  In step 4, the aperture threshold value Fk is read from the lens memory 26, and in the subsequent step 5, the exposure calculation result or the manually set photographing aperture value F by the photographer is compared with the threshold value Fk. When the photographing aperture value F is larger than the threshold value Fk, the routine proceeds to step 6 where the aperture 24 is driven by the drive circuit 8 and the actuator 25 to set the open aperture value F0. Note that, as described above, an aperture value smaller than the photographing aperture value F may be set, or an aperture value not more than the threshold value Fk may be set. On the other hand, if the photographing aperture value F is less than or equal to the threshold value Fk, the process proceeds to step 7 where the diaphragm 24 is driven by the drive circuit 8 and the actuator 25 to set the photographing aperture value F.

  In step 8, the shutter 3 is opened and the mirrors 9 and 10 are retracted from the photographing optical path (mirror up), and in the subsequent step 9, contrast detection AF is performed using the output of the image sensor 2. At this time, the contrast detection method AF is performed using the pixel output of the area of the image sensor 2 corresponding to the focus detection area selected in the phase difference detection method AF. In this flowchart, since the single AF mode is used as described above, the focusing lens 21 is driven by the drive circuit 8 and the actuator 25 and focused by the contrast detection AF, and then the shutter 3 is closed in step 10 and the mirror 9, 10 is returned to the photographing optical path (mirror down).

  In step 11, it is confirmed whether or not the full aperture value F0 is set for the aperture 24. If the full aperture value F0 is set, the process proceeds to step 12, and is set to the photographing aperture value F by the drive circuit 8 and the actuator 25. Try again. Note that even when an aperture value smaller than the shooting aperture value F is set as the aperture value in the contrast detection method AF in step 6 or an aperture value equal to or smaller than the threshold value Fk is set, shooting is performed in step 11. Reset the aperture value to F. On the other hand, when the photographing aperture value F is set for the aperture 24, it is left as it is. In step 13, the shutter button is fully pressed by the release full press switch of the operation member 16. If the shutter button has not been fully pressed, the process proceeds to step 14 to check whether the shutter button remains in the half-pressed state. If the shutter button remains in the half-pressed state, the process returns to step 13 to wait for the full-press operation. . If the shutter button is not half-pressed, the shooting operation is terminated.

  If it is detected in step 13 that the shutter button has been fully pressed, the process proceeds to step 15 where the shutter 3 is opened for the time of the exposure calculation result or the shutter speed set manually by the photographer, and the mirrors 9 and 10 are raised. The imaging device 2 is exposed to perform imaging, the captured image is recorded in a recording device (not shown) such as a memory card, and the imaging operation ends.

  In addition to the single AF mode described above, the focus mode includes a continuous AF mode in which focus detection is continued while the half-press button is pressed. In the operation flow in the case of the continuous AF mode, steps 13 and 14 in the flow of FIG. 3 are deleted, and instead, steps 9-1, 9-2, and 9- 3 should be added. Since the added steps 9-1, 9-2, and 9-3 are the same as the operations of steps 13, 14, and 10, respectively, the description of the operations of those steps is omitted.

<< Second Embodiment of the Invention >>
A second embodiment in which the present invention is applied to a compact digital camera will be described. FIG. 4 shows the configuration of a compact digital camera according to the second embodiment. Note that components similar to those of the digital single-lens reflex camera shown in FIG. The camera according to the second embodiment basically performs photometry and focus detection using an image pickup device 2A for image acquisition, and the image pickup device 2A has a shutter function. Live view function with LCD color monitor. The camera shown in FIG. 4 shows an example in which the camera body 1A and the lens barrel 20A are integrated. However, of course, a camera with a replaceable lens barrel may be used. A viewfinder such as a viewfinder may be provided.

  The focus detection calculation circuit 6A adjusts the focus of the photographic lens 23A by the contrast detection method AF based on the pixel output in the area of the image sensor 2A corresponding to the focus detection area preset in the photographic screen. In the compact camera of the second embodiment, the phase difference detection AF is not performed, and the focus adjustment of the photographing lens 23A is performed only by the contrast detection AF. The control circuit 7A performs an exposure calculation based on the pixel output of the image sensor 2A, and calculates a shutter speed and an aperture value corresponding to the luminance of the shooting screen. When the manual exposure shooting mode is set, the shutter speed and aperture value set by the photographer using the operation member 16A are used. The control circuit 7A performs charge accumulation of the image sensor 2A for the exposure calculation result or the time of the shutter speed manually set by the photographer, thereby realizing the shutter function. The control circuit 7A also reads a through image from the image sensor 2A and displays the image on an LCD color monitor (not shown) on the back of the camera to realize a live view function.

  Also in the compact camera of the second embodiment, when the photographing aperture value F as the exposure calculation result or the photographing diaphragm value F manually set by the photographer is equal to or smaller than a predetermined threshold value Fk, that is, the photographing aperture value F Is within the range from the full aperture value F0 to the threshold value Fk, the contrast detection method AF is not performed with the full aperture value F0, and after the contrast detection method AF is performed with the photographing aperture value F, the photographing is performed. Shooting is performed with an aperture value F.

  On the other hand, when the shooting aperture value F is larger than the threshold value Fk, that is, when the shooting aperture value F is narrowed down below the threshold value Fk, the aperture is smaller than the open aperture value F0 or the shooting aperture value F. The contrast detection method AF is performed with a value or an aperture value equal to or less than the threshold value Fk, and then the image is narrowed down to the photographing aperture value F for photographing. In the second embodiment, the aperture threshold value Fk is stored in advance in a memory built in the control circuit 7.

  FIG. 5 is a flowchart (solid line flow) showing the photographing operation of the second embodiment. This flowchart is an operation flow when the AF mode is the single AF mode. When the control circuit 7A detects that the shutter button is half-pressed by the release half-press switch of the operation member 16A in step 21, this control operation is started. In step 22, the image pickup device 2A takes an image for photometry, performs an exposure calculation based on the image pickup result, and determines the shutter speed and the photographing aperture value F. In the manual exposure shooting mode, the shutter speed and shooting aperture value F manually set by the photographer using the operation member 16 are used.

  In step 23, the exposure calculation result or the manually set photographing aperture value F by the photographer is compared with a threshold value Fk stored in advance in a memory (not shown) of the control circuit 7A. When the photographing aperture value F is larger than the threshold value Fk, the routine proceeds to step 24, where the aperture 24 is driven by the drive circuit 8 and the actuator 25 to set the open aperture value F0. Note that, as described above, an aperture value smaller than the photographing aperture value F may be set, or an aperture value not more than the threshold value Fk may be set. On the other hand, if the photographing aperture value F is less than or equal to the threshold value Fk, the process proceeds to step 25, where the diaphragm 24 is driven by the drive circuit 8 and the actuator 25 to set the photographing aperture value F.

  In step 26, contrast detection AF is performed. At this time, a contrast detection method using the pixel output of the region of the image sensor 2 corresponding to the focus detection area selected by the photographer with the focus detection area selection switch of the operation member 16 or the focus detection area automatically selected by the camera. AF is performed, and the focusing lens 21 is driven and focused by the drive circuit 8 and the actuator 25.

  In step 27 after the contrast detection method AF, it is confirmed whether or not the full aperture value F0 is set for the aperture 24. When the full aperture value F0 is set, the process proceeds to step 28, where the drive circuit 8 and the actuator 25 reset the photographing aperture value F. Note that even when an aperture value smaller than the shooting aperture value F is set as the aperture value in the contrast detection method AF in step 24, or an aperture value less than the threshold value Fk is set in step 28, shooting is performed in step 28. Reset the aperture value to F. On the other hand, when the photographing aperture value F is set for the aperture 24, it is left as it is. In the operation flow in the case of the continuous AF mode, steps 29 and 30 are deleted from FIG. 5, and steps 26-1 and 26-2 may be added at the positions indicated by broken lines instead. The added operations of steps 26-1 and 26-2 are the same as the operations of steps 29 and 30.

  In step 29, the shutter button full-press operation is confirmed by the release full-press switch of the operation member 16. If the shutter button is not fully pressed, the process proceeds to step 30 to check whether or not the shutter button is half-pressed. If the shutter button is half-pressed, the process returns to step 29 to wait for the full-press operation. On the other hand, when the shutter button is not half-pressed, the shooting operation is terminated. If it is detected in step 29 that the shutter button is fully pressed, the process proceeds to step 31 where charge is accumulated for the time of the shutter speed by the image sensor 2 and the photographed image is recorded in a recording device (not shown) such as a memory card. End the shooting operation.

  As described above, according to the embodiment, the focus adjustment state of the photographing lenses 23 and 23A is detected based on the image signals output from the imaging elements 2 and 2A, and the photographing lenses 23 and 23A are detected based on the focus detection result. When the focus adjustment is performed, the aperture value at the time of focus detection is set according to the set aperture value F at the time of shooting, so that the focus adjustment time can be shortened while preventing the focus shift at the time of shooting. Can do.

The figure which shows the structure of 1st Embodiment. The figure which shows the mode of a change of a focus position with respect to F value of the lens which used the zooming lens position as a parameter The flowchart which shows the imaging | photography operation | movement of 1st Embodiment. The figure which shows the structure of 2nd Embodiment. The flowchart which shows the imaging | photography operation | movement of 2nd Embodiment.

Explanation of symbols

1, 1A Digital camera 2, 2A Image sensor 7, 7A Control circuit 8, 8A Drive circuit 16, 16A Operation member 21, 21A Focusing lens 22, 22A Zooming lens 23, 23A Shooting lens 24, 24A Aperture 25, 25A Actuator

Claims (8)

An image sensor that receives light passing through a photographing optical system including an aperture and outputs an image signal; and
A shooting aperture setting means for setting the aperture value at the time of shooting,
A focus adjusting unit that detects a focus adjustment state of the photographing optical system based on an image signal output from the image sensor, and performs focus adjustment of the photographing optical system based on a focus detection result;
An imaging apparatus comprising: a focus detection aperture setting unit that sets the aperture value at the time of focus detection by the focus adjustment unit according to the aperture value at the time of shooting set by the imaging aperture setting unit. . The imaging apparatus according to claim 1,
The focus detection aperture setting means sets the aperture value at the time of shooting to the aperture value at the time of focus detection when the aperture value at the time of shooting is equal to or less than a preset threshold value. apparatus. In the imaging device according to claim 1 or 2,
When the aperture value at the time of shooting is larger than a preset threshold value, the focus detection aperture value setting means sets a value smaller than the aperture value at the time of shooting as the aperture value at the time of focus detection. An imaging apparatus characterized by that. The imaging device according to claim 3.
An imaging apparatus, wherein an aperture value equal to or smaller than the threshold value is set as an aperture value at the time of focus detection. In the imaging device according to claim 3 or 4,
A photometric means for measuring subject brightness;
The aperture value at the time of focus detection is determined based on a photometric result of the photometric means. In the imaging device according to claim 3 or 4,
An imaging apparatus, wherein an open aperture value is set as an aperture value at the time of focus detection. In the imaging device according to any one of claims 2 to 6,
If the aperture value at the time of shooting is equal to or greater than the threshold value, the threshold value causes a focus shift on the imaging screen by the image sensor even when the aperture is reduced from the open aperture value to the shooting aperture value. An image pickup apparatus having an aperture value at a non-crushing boundary. The imaging apparatus according to claim 7,
An imaging apparatus, wherein the threshold value is changed according to a lens position of at least one of a focusing lens and a zooming lens in the photographing optical system.

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