JP2017005495A - Imaging apparatus, method for controlling the same, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of performing flickerless photographing in which a flicker is reduced by detecting the flicker during photographing in a live view photographing mode by an imaging apparatus.SOLUTION: The imaging apparatus includes flicker detection means 110 for measuring the light quantity of a luminous flux which passes through a photographic optical system 115, is reflected by a mirror mechanism 109, and then, is guided to an eyepiece part 105 through finder optical systems 101 and 102 by photometric means 103, to perform flicker detection processing on the basis of a measured light quantity, in a finder photographing mode and for measuring the light quantity of the luminous flux entering from the eyepiece part 105 by the photometric means 103, to perform the flicker detection processing on the basis of the measured light quantity, in the live view photographing mode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an improvement in flicker detection technology in an imaging apparatus such as a digital single-lens reflex camera.

  Some imaging apparatuses such as a digital camera have a live view function of sequentially converting an imaging signal read from an imaging element into a display image signal and outputting the image signal to a display unit. In particular, a digital single-lens reflex camera is provided as a live view shooting mode as distinguished from a finder shooting mode in a mirror down state because it is necessary to maintain a mirror up state during live view display.

  In the live view shooting mode, images that can be taken instead of the viewfinder are sequentially displayed on the display unit for the photographer, and therefore it is necessary to update the images that can be taken at a constant cycle (frame rate).

  By the way, when photographing under a light source (flicker light source) that repeatedly flickers, such as a fluorescent lamp, flickering is reflected in the photographed image, and an unintended photographing result may be obtained. This is because the relationship between the photographing time and the phase of the flicker light source is not uniquely determined.

  Therefore, flickerless imaging is known in which shooting is performed by capturing a specific phase of the flicker light source, and the relationship between the shooting time and the phase of the flicker light source is uniquely determined to minimize the influence of the flicker light source.

  However, in the viewfinder shooting mode, the light reflected by the mirror can be measured periodically to detect the flicker frequency and phase, so flicker shooting is possible. Because there is no flickerless shooting. In the live view shooting mode, the image sensor is driven at the frame rate, so it is difficult to detect flicker using the image sensor in the same manner as in the viewfinder shooting mode.

  Therefore, conventionally, in order to avoid the influence of the flicker light source in the live view shooting mode, for example, a technique for performing high-speed accumulation for flicker detection before starting live view shooting using an image sensor has been proposed (Patent Literature). 1).

JP 2013-42298 A

  However, in Patent Document 1, even if flicker can be detected at the start of live view shooting, it is not possible to cope with a change in flicker state during live view shooting. Even if flicker is not detected at the start of live view shooting, flicker cannot be detected if flicker occurs during live view shooting. For this reason, in the live view shooting mode, an image including the influence of an unintended flicker light source is shot.

  If the frequency of the flicker light source is ideally maintained, flickerless shooting can be continued based on the flicker detection result at the start of live view shooting. There is a time lag in time. For this reason, it is difficult to perform flickerless shooting based on the flicker detection result at the start of live view shooting.

  Therefore, an object of the present invention is to provide a technique that enables flicker-less shooting with reduced flicker by enabling flicker to be detected during shooting in a live view shooting mode by an imaging apparatus.

  In order to achieve the above object, the imaging apparatus of the present invention reflects a light beam that has entered the imaging optical path and passed through the imaging optical system at the time of finder observation and guides it to the eyepiece through the finder optical system. A mirror mechanism that guides the light beam that has been retracted from the imaging optical path and passed through the imaging optical system to the imaging unit, and the electrical signal photoelectrically converted by the imaging unit is converted into an image signal, and the converted image signal is used as a live view image. A flicker detection process is performed on the basis of the light quantity measured by the display means for displaying on the display section, the photometric means disposed between the viewfinder optical system and the eyepiece, and measuring the light quantity of the luminous flux. Flicker detection means, a viewfinder shooting mode for shooting while observing a subject through the eyepiece unit, and a live view image displayed on the display unit according to a user operation Switching means for switching between live view shooting modes in which shooting is performed while viewing, and in the finder shooting mode, the flicker detection means passes through the finder optical system from the shooting optical system measured by the photometry means. The flicker detection processing is performed based on the amount of light flux guided to the eyepiece, and in the live view shooting mode, based on the amount of light incident from the eyepiece measured by the photometry means. The flicker detection process is performed.

  According to the present invention, since flicker can be detected during shooting in the live view shooting mode by the imaging apparatus, flickerless shooting with reduced flicker is possible even in the live view shooting mode.

(A) is a schematic sectional side view in viewfinder imaging | photography mode of the digital camera which is 1st Embodiment of the imaging device of this invention, (b) is a schematic sectional side view in live view imaging | photography mode. It is a side view of a digital camera. It is a block diagram explaining the drive system of a digital camera. (A) is a graph showing an example of detection of a flicker light source by the photometry unit, and (b) is a graph for explaining an example of calculating a phase at which the brightness of the flicker light source is maximized. It is a schematic sectional side view of the camera body in live view shooting mode. It is a flowchart explaining the operation | movement at the time of performing flickerless imaging | photography of a digital camera. (A) is a graph showing the relationship between time, luminance and exposure in normal shooting, and (b) is a graph showing the relationship between time, luminance and exposure in flickerless shooting. FIG. 7 is a flowchart illustrating details of flicker detection setting value / threshold value determination processing corresponding to a live view shooting mode in step S602 of FIG. 6; It is a figure explaining the relationship between the position of the digital camera with respect to a flicker light source, and the light quantity of a finder reverse incident light. It is a schematic sectional side view of the camera main body in the live view imaging | photography mode of the digital camera which is 2nd Embodiment of the imaging device of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1A is a schematic side cross-sectional view in the finder shooting mode of the digital camera which is the first embodiment of the imaging apparatus of the present invention, and FIG. 1B is a schematic side cross-sectional view in the live view shooting mode. . FIG. 2 is a side view of the digital camera.

  In the digital camera of this embodiment, as shown in FIG. 1A, an interchangeable lens barrel 2 is detachably mounted on the front side (subject side) of the camera body 1. The camera body 1 and the lens barrel 2 are electrically connected via a mount contact 112, thereby enabling communication between the camera control unit 110 of the camera body 1 and the lens control unit 113 of the lens barrel 2. It is possible.

  The camera control unit 110 adjusts the position of the lens group 115 constituting the photographing optical system in the optical axis direction and controls the diaphragm 114 via the lens control unit 113. The camera control unit 110 includes a CPU, a ROM, a RAM, and the like (not shown), and controls the operation of the entire camera using the RAM as a work memory in accordance with programs and data stored in the ROM. Similarly, the lens control unit 113 includes a CPU, a ROM, a RAM, and the like (not shown), and controls the operation of the lens barrel 2 using the RAM as a working memory according to programs and data stored in the ROM.

  In the finder photographing mode shown in FIG. 1A, the light beam from the subject is collected through the lens group 115 of the lens barrel 2, and enters the photographing optical path during finder observation to enter a mirror-down state. The light is reflected by the main mirror 109 and applied to the focus plate 101. The focus plate 101 constitutes a finder optical system, and is disposed at a position where a light beam is formed as a shootable image. The main mirror of the mirror mechanism 109 is a half mirror, and the light beam that has passed through the main mirror is reflected by the sub mirror and guided to the autofocus unit 111.

  The pentaprism 102 forms a finder optical system together with the focus plate 101, and guides a shootable image formed on the focus plate 101 to the eyepiece 104. Thus, the photographer can observe the image formed on the focus plate 101 by looking into the eyepiece lens 104 through the eyepiece unit 105. The photometry unit 103 converts the light beam irradiated from the imaging surface of the focus plate 101 into an electrical signal and outputs it to the camera control unit 110. The camera control unit 110 calculates the control amount of the digital camera by measuring the amount of light incident on the lens barrel 2 based on the electrical signal from the photometry unit 103.

  The autofocus unit 111 includes a phase difference detection type autofocus sensor. The camera control unit 110 calculates the amount of movement for adjusting the focusing lens included in the lens group 115 to the in-focus position from the focus detection value from the autofocus unit 111, and based on the calculation result, the lens control unit 113 Adjust the position of the focus lens.

  In the live view photographing mode shown in FIG. 1B, the mirror mechanism 109 is retracted from the photographing optical path to enter the mirror-up state, and the shutter 107 is also retracted from the photographing optical path so that the image sensor 108 is exposed to the photographing optical path. . The image sensor 108 is configured by, for example, a CMOS sensor, and photoelectrically converts a subject image formed through the lens group 115 of the lens barrel 2. In addition, a display unit 106 composed of an LCD or the like is provided on the back side of the camera body 1. The display unit 106 displays setting values of the digital camera in addition to the captured image and the live view image. .

  FIG. 2 is a side view of the digital camera. As shown in FIG. 2, the camera body 1 is provided with a release button 201 and a live view button 202. When the release button 201 is pressed halfway, a first switch (not shown) is turned on, and when the release button 201 is fully pressed, a second switch (not shown) is turned on.

  The camera control unit 110 acquires information from the photometry unit 103 and the autofocus unit 111 based on the ON signal of the first switch, and sets an optimal control amount for an image that can be captured with respect to the camera body 1 and the lens barrel 2. Calculate. If it is necessary to control the camera body 1 and the lens barrel 2 before shooting, the camera control unit 110 changes the states of the camera body 1 and the lens barrel 2 based on the calculated control amount. Further, the camera control unit 110 controls the camera body 1 and the lens barrel 2 to be in an optimal state for photographing based on the ON signal of the second switch, and causes the mirror mechanism 109 to perform a mirror up operation. As a result, the light flux of the subject is exposed by the image sensor 108 and a photographing process is performed.

  When the live view button 202 is pressed, the camera control unit 110 switches between the finder shooting mode shown in FIG. 1A and the live view shooting mode shown in FIG. In the live view shooting mode shown in FIG. 1B, as described above, the subject luminous flux that has passed through the lens group 115 of the lens barrel 2 forms an image on the image sensor 108, and the image sensor 108 displays the formed subject image. Is converted into an electric signal by photoelectric conversion. The camera control unit 110 converts the electrical signal converted by the image sensor 108 into an image signal and displays it on the display unit 106. Thereby, the live view image is displayed on the display unit 106.

  By the way, in the live view shooting mode, since the photographer performs shooting while looking at the live view image displayed on the display unit 106, it is necessary to sequentially update the images at a constant cycle (frame rate). The frame rate is generally determined by a standard such as 50 Hz or 60 Hz, but may be set to a period different from the standard such as 120 Hz.

  FIG. 3 is a block diagram illustrating a drive system of the digital camera. In FIG. 3, the lens driving unit 302 and the aperture driving unit 301 are controlled by the lens control unit 113 in response to a request from the camera control unit 110, thereby adjusting the position of the lens group 115 in the optical axis direction and the aperture 114. Drive.

  The mirror driving unit 303 drives the mirror mechanism 109 to the mirror down position shown in FIG. 1A and the mirror up position shown in FIG. 1B in response to a request from the camera control unit 110. The shutter control unit 304 drives the shutter 107 to the closed position shown in FIG. 1A and the open position shown in FIG. 1B in response to a request from the camera control unit 110.

  The tilt measurement unit 305 detects the tilt amount of the digital camera with respect to the horizontal direction and the vertical direction. The tilt amount detected by the tilt measuring unit 305 is constantly updated, and the camera control unit 110 can acquire the tilt amount of the digital camera from the tilt measuring unit 305 as necessary.

  The signal processing unit 306 converts the electrical signal output from the image sensor 108 into an image signal, and performs image processing such as rotation, expansion, and reduction of the image signal on the converted image signal. Although the processing content of the signal processing unit 306 is set / changed by the camera control unit 110, the processing content may be set / changed by the signal processing unit 306 in accordance with the electrical signal acquired from the image sensor 108. In the finder shooting mode, the image signal processed by the signal processing unit 306 is sent to the display unit 106 after being shot and displayed as a shot image. At the same time, the shot image and shooting information are recorded in the recording unit 307.

  The recording unit 307 records the image signal output from the signal processing unit 306 along with shooting. A rewritable nonvolatile memory can be applied to the recording unit 307. The recording unit 307 can record an image signal that has been compression-encoded by a predetermined method.

  The image sensor 108 accumulates charges in accordance with the control of the camera control unit 110 and outputs a charge or a value obtained by converting the charge into a digital signal. A global shutter method and a rolling shutter method are known as a charge accumulation method and a readout method of the image sensor 108.

  In the global shutter system, since all the pixels of the image sensor 108 start to accumulate charges at the same time, charges are accumulated at the same time, but it takes time to read out the charges. On the other hand, in the rolling shutter method, charge accumulation is started in order from one column of the image sensor 108, and the charge is read out in the order of accumulation, thereby enabling a short readout time.

  In the digital camera having the above-described configuration, when an attempt is made to take an image under a flicker light source such as a fluorescent lamp that repeatedly blinks, an image with unintended brightness is taken with a global shutter CMOS sensor. In addition, in a rolling shutter type CMOS sensor, flickering of a flicker light source may be recorded in an image as a stripe pattern.

  As a method for suppressing the influence of the flicker light source, a method for uniquely determining the relationship between the photographing time and the flicker phase is known. By shooting at a specific phase of flicker, the shooting result always has the same brightness, and the influence of the flicker light source can be reduced. Such a photographing method is generally called flickerless photographing. In order to perform flickerless photographing, it is necessary to detect the frequency and phase of a flicker light source.

  In the finder photographing mode, as shown in FIG. 1A, the ambient light enters the photometry unit 103, so that the frequency and phase of the flicker light source can be sequentially detected by the photometry unit 103.

  FIG. 4A is a graph showing an example of detection of a 50 Hz flicker light source by the photometry unit 103, and FIG. 4B is a graph for explaining an example of calculating the phase at which the brightness of the flicker light source is maximized.

  As shown in FIG. 4A, the camera control unit 110 measures the change of the flicker light source for two periods (12 times) at a period adjusted to 1.667 ms using the photometric unit 103. Thus, it is possible to detect how many times the measurement result has become brightest since the start of accumulation.

  Then, the camera control unit 110 performs the interpolation calculation from the detected measurement points and the assumed points before and after the measurement points, so that the phase with the highest brightness is obtained as shown in FIG. It can be calculated. Further, the camera control unit 110 can determine the cycle of the flicker light source by taking the difference between the measurement points for each cycle based on the periodicity of the flicker light source.

  Specifically, in the case of the 50 Hz flicker light source shown in FIG. 4A, the difference between the first measurement point and the seventh measurement point is substantially zero. Similarly, the difference is taken in order, such as the second measurement point and the eighth measurement point, the third measurement point and the ninth measurement point, and the total value of the differences is calculated.

  At this time, if the flicker light source is 50 Hz, the total difference value should be calculated to be close to zero, but if the flicker light source is 60 Hz, a large difference value is obtained. Thereby, it can be determined that the cycle of the flicker light source is 50 Hz. It is possible to detect flicker in this way in the finder shooting mode.

  On the other hand, in the live view shooting mode, since the light flux forms an image on the image sensor 108, it is necessary to detect flicker by the image sensor 108. However, in the live view shooting mode, since it is necessary to display an image signal at a constant frame rate on the display unit 106, the image sensor 108 is detected by a detection method similar to the flicker detection method in the finder shooting mode in order to detect flicker. It cannot be operated.

  FIG. 5 is a schematic sectional side view of the camera body 1 in the live view shooting mode. As shown in FIG. 5, in the live view shooting mode, since the mirror mechanism 109 is retracted from the shooting optical path in the mirror-up state, the light flux to the photometry unit 103 is shielded, but the eyepiece 105 is shielded. Not.

  For this reason, the light beam incident from the eyepiece 105 is applied to the photometry unit 103 through the reflection of the pentaprism 102. This is called finder reverse incident light, and since the light beam from the flicker light source 501 (see FIG. 9) from above is irradiated to the photometric unit 103, flicker can be detected.

  In the present embodiment, in the live view shooting mode, flicker detection is performed based on the amount of finder reverse incident light that is incident from the eyepiece unit 105 and irradiated onto the photometric unit 103 via the pentaprism 102. Enables flickerless shooting. Details will be described below.

  FIG. 6 is a flowchart for explaining the operation when the digital camera performs flickerless shooting. Each process in FIG. 6 is executed by the CPU after a program stored in the ROM or the like of the camera control unit 110 is expanded in the RAM.

  In FIG. 6, in step S601, the camera control unit 110 determines whether the mirror mechanism 109 is in a mirror-down state or a mirror-up state. If the mirror mechanism 109 is in the mirror up state, the camera control unit 110 determines that the live view shooting mode is selected, and proceeds to step S602. If the mirror mechanism 109 is in the mirror down state, the camera control unit 110 determines that the viewfinder shooting mode is set. Then, the process proceeds to step S603.

  In step S602, the camera control unit 110 determines a flicker detection setting value / threshold corresponding to the live view shooting mode, and the process advances to step S604. Details of the flicker detection setting value / threshold value determination processing corresponding to the live view shooting mode will be described later with reference to FIG. In step S603, the camera control unit 110 determines a flicker detection setting value / threshold corresponding to the finder shooting mode, and the process advances to step S604.

  In step S604, the camera control unit 110 performs flicker detection processing using the flicker detection setting value / threshold value determined in step S602 or step S603, calculates the flicker frequency and the luminance value peak timing, and performs step S605. Proceed to

  In step S605, the camera control unit 110 returns to step S601 if the release button 201 is half-pressed or not operated, and proceeds to step S606 if the release button 201 is fully pressed. .

  In step S606, the camera control unit 110 determines whether or not flickerless shooting is set by a user operation. If flickerless shooting is set, the process proceeds to step S607, and if not set, The process proceeds to step S608.

  In step S607, the camera control unit 110 proceeds to step S608 if flicker is not detected in the flicker detection process in step S604, and proceeds to step S609 if flicker is detected.

  In step S608, the camera control unit 110 performs normal shooting according to the shooting mode, and ends the process. In step S609, the camera control unit 110 performs flickerless shooting according to the shooting mode, and ends the process. In the flickerless shooting, the shooting timing is adjusted based on the peak timing at which the flicker frequency and the luminance value detected in step S604 are maximized.

  FIG. 7A is a graph showing the relationship between time, luminance, and exposure in normal shooting, and FIG. 7B is a graph showing the relationship between time, luminance, and exposure in flickerless shooting.

  In the normal photographing shown in FIG. 7A, photographing is performed without considering flickering of the flicker light source, and therefore unintended light and darkness enters at the photographing timing (shaded portion). On the other hand, in the flickerless shooting shown in FIG. 7B, the shooting is performed in consideration of the luminance peak timing being the center of shooting, so that the amount of unintentional blinking can be minimized.

  FIG. 8 is a flowchart for explaining the details of the flicker detection setting value / threshold value determination processing corresponding to the live view shooting mode in step S602 of FIG. FIG. 9 is a diagram for explaining the relationship between the position of the digital camera with respect to the flicker light source 501 and the amount of finder reverse incident light.

  In FIG. 8, in step S801, the camera control unit 110 acquires the amount of tilt of the digital camera with respect to the horizontal and vertical directions detected by the tilt measurement unit 305, and the process proceeds to step S802.

  Here, as shown in FIG. 9, the light quantity of the finder reverse incident light with respect to the digital camera of the flicker light source 501 mounted above the digital camera differs depending on the inclination of the digital camera. That is, when the digital camera is directed upward, the eyepiece 105 is directed downward, so that the amount of finder reverse incident light is reduced. When the digital camera is directed downward, the eyepiece 105 is moved upward. Therefore, the amount of finder reverse incident light increases.

  In step S802, the camera control unit 110 determines a flicker detection setting value and a threshold value by the photometry unit 103 in consideration of the amount of finder reverse incident light according to the tilt amount of the digital camera acquired in step S801. The process proceeds to S803. The threshold value determined here is determined so that the threshold value when the digital camera faces straight down is maximized, and the threshold value when the digital camera faces straight up is minimized. Otherwise, the tilt amount of the digital camera The intermediate value is calculated according to

  In step S803, the camera control unit 110 determines whether or not flicker was detected in the previous process in step S604 of FIG. 6. If not detected, the camera control unit 110 ends the set value / threshold value determination process and detects it. If so, the process proceeds to step S804.

  In step S804, in order to make it easy to maintain the flicker detection state, the camera control unit 110 recalculates and changes the threshold calculated in step S802 so as to be low, and ends the process.

  As described above, in the present embodiment, flicker can be detected by the photometry unit 103 via the eyepiece unit 105 during shooting in the live view shooting mode by the digital camera. This enables flickerless shooting with reduced flicker even in the live view shooting mode.

(Second Embodiment)
Next, a digital camera that is a second embodiment of the imaging apparatus of the present invention will be described with reference to FIG. FIG. 10 is a schematic sectional side view of the camera body in the live view shooting mode. In addition, the same code | symbol is attached | subjected and demonstrated about the part which overlaps with the said 1st Embodiment.

  In the present embodiment, in the live view shooting mode, the ambient light is incident on the upper part of the camera body 1 in order to irradiate the photometric unit 103 with ambient light other than the finder reverse incident light via the eyepiece 105. A take-in unit 601 is provided. The ambient light capturing unit 601 is opened and closed by driving an opening / closing drive unit (not shown) under the control of the camera control unit 110.

  The ambient light capturing unit 601 is closed and shielded from light in the finder photographing mode so that light does not enter the pentaprism 102. When the live view button 202 is pressed to switch from the finder shooting mode to the live view shooting mode, the camera control unit 110 retracts the mirror mechanism 109 from the shooting optical path and opens the ambient light capturing unit 601. When the ambient light capturing unit 601 is opened, ambient light is reflected by the pentaprism 102 and the focus plate 101 constituting the finder optical system, and is irradiated to the photometric unit 103.

  Then, the camera control unit 110 performs flicker detection based on the amount of ambient light irradiated to the photometry unit 103 via the eyepiece unit 105 and the ambient light capturing unit 601. In addition, since the amount of light larger than that of the finder reverse incident light of the first embodiment is obtained by providing the ambient light capturing unit 601, step S802 in FIG. 8 is different from the first embodiment. A flicker detection set value and a threshold value are calculated. Other configurations and operational effects are the same as those in the first embodiment.

  In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in the above-described embodiment, a digital camera that mainly captures a still image is exemplified as the imaging device. However, the imaging device is not particularly limited as long as the imaging device has a flickerless imaging function.

  The present invention can also be realized by executing the following processing. That is, the present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus read the program. It can also be realized by processing to be executed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 1 Camera body 2 Lens barrel 101 Focusing plate 102 Penta prism 103 Metering unit 105 Eyepiece part 106 Display part 108 Image pick-up element 109 Mirror mechanism 110 Camera control part 115 Lens group 202 Live view button 306 Signal processing part 601 Ambient light taking part

Claims (7)

Reflects the light beam that has entered the imaging optical path during the viewfinder observation and has passed through the imaging optical system, led to the eyepiece through the viewfinder optical system, and retracted from the imaging optical path to pass the imaging optical system during imaging. A mirror mechanism leading to the imaging means;
Display means for converting the electrical signal photoelectrically converted by the imaging means into an image signal and displaying the converted image signal as a live view image on a display unit;
A photometric means that is disposed between the finder optical system and the eyepiece, and measures the amount of light flux;
Flicker detection means for performing flicker detection processing based on the amount of light measured by the photometry means;
Switching means for switching between a finder photographing mode for photographing while observing a subject through the eyepiece unit and a live view photographing mode for photographing while viewing a live view image displayed on the display unit according to a user operation And comprising
In the finder photographing mode, the flicker detection unit performs the flicker detection process based on a light amount of a light beam that is measured by the photometry unit and is guided from the photographing optical system to the eyepiece through the finder optical system. And the flicker detection process is performed in the live view shooting mode based on a light amount of a light beam incident from the eyepiece unit, which is measured by the photometry unit.   The imaging apparatus according to claim 1, wherein the flicker detection unit performs calculation using different setting values and threshold values in the finder shooting mode and the live view shooting mode in the flicker detection processing. Inclination measuring means for detecting the amount of inclination with respect to the horizontal direction and the vertical direction of the imaging device,
2. The flicker detection unit, in the live view shooting mode, changes a setting value and a threshold value for calculation in the flicker detection process according to a tilt amount acquired from the tilt measurement unit. Or the imaging device of 2. It has an ambient light capture unit that receives ambient light.
The ambient light capturing unit is closed in the finder shooting mode, shields ambient light, and is opened in the live view shooting mode. The incident ambient light beam is transmitted through the finder optical system to the photometric means. The imaging apparatus according to claim 1, wherein the imaging apparatus is guided by the following.   The imaging apparatus according to claim 4, wherein the flicker detection unit changes a setting value and a threshold value for calculation in the flicker detection process in the live view shooting mode. Reflects the light beam that has entered the imaging optical path during the viewfinder observation and has passed through the imaging optical system, led to the eyepiece through the viewfinder optical system, and retracted from the imaging optical path to pass the imaging optical system during imaging. An imaging apparatus control method comprising: a mirror mechanism that leads to an imaging unit; a photometric unit that is disposed between the finder optical system and the eyepiece unit;
A display step of converting the electrical signal photoelectrically converted by the imaging means into an image signal and displaying the converted image signal on a display unit as a live view image;
A flicker detection step for performing flicker detection processing based on the amount of light measured by the photometric means;
A switching step of switching between a finder shooting mode in which shooting is performed while observing a subject through the eyepiece unit and a live view shooting mode in which shooting is performed while viewing a live view image displayed on the display unit in accordance with a user operation. And comprising
In the finder photographing mode, the flicker detection step performs the flicker detection process based on the light amount of the light beam guided from the photographing optical system to the eyepiece unit through the finder optical system, which is measured by the photometry unit. And performing the flicker detection process based on a light amount of a light beam incident from the eyepiece unit, which is measured by the photometry unit, in the live view shooting mode.   A program for causing a computer to execute each step of the method for controlling an imaging apparatus according to claim 6.