JP4931250B2 - Imaging apparatus and control method - Google Patents

Description

The present invention relates to an imaging apparatus and a control how that can be taken by the flash.

  Conventionally, various techniques relating to flash emission control when performing flash photography with an imaging device (camera, digital still camera) have been proposed. Prior to the exposure operation, flash pre-emission (preliminary emission) is performed, and the reflected light of the subject by pre-emission is measured for each of the divided areas in the imaging screen (subject image observed by the viewfinder or display). This is a method for determining the main light emission amount. This is because an appropriate light emission amount can be determined for various shooting scenes by determining the main light emission amount by a predetermined algorithm based on the photometric results for each divided area.

  Regarding the above flash emission control, the following imaging method has been proposed so that an appropriate exposure amount can be obtained stably (see, for example, Patent Document 1). First, the ratio R (i) between the photometric value P (i) of each photometric area immediately before the pre-flash is emitted and the photometric value H (i) of each photometric area when the pre-flash is executed is measured by Calculate for each area. The largest R (i) obtained is extracted as the reference value baseR, and the reference value baseR is compared with the value of R (i) of each photometric area to obtain the weighting coefficient W (i) for each photometric area. decide. Next, the actual light emission amount is calculated based on the weighted average result obtained by weighted averaging of the reflected light amount at the time of pre-emission in each photometry area according to the weighting coefficient W (i).

  Further, the following imaging method has been proposed in order to detect a human face region and obtain a good exposure even when the luminance of the subject is not sufficient (see, for example, Patent Document 2). First, it is detected whether or not a person's face area exists in the image based on the image captured at the time of flash pre-flash. Next, a light control area is determined according to the detected face area, and the main light emission amount is calculated according to a photometric value at the time of pre-emission in the determined light control area.

Further, the following imaging method relating to flash emission control has been proposed (see, for example, Patent Document 3). A predetermined subject image (specifically, a human face) is extracted from the imaging signal obtained by imaging the subject, the distance to the subject is calculated based on the size of the extracted subject image, and the calculation result is flashed. Used for light emission control and the like.
JP 2005-275265 A JP 2005-184508 A Japanese Patent Laid-Open No. 2003-075717

  According to the technique described in Patent Document 1, stable exposure can be obtained in many shooting scenes, and an imaging result with little change in exposure can be obtained even when the same scene is shot with a slight composition change. . However, as a rule of thumb, among the photometric areas, the largest R (i) satisfying the predetermined condition is regarded as the main subject area, and the reference value baseR is extracted from the amount of reflected light in that area. For this reason, the weighting coefficient W (i) tends to increase when it is present at a relatively short distance in the imaging screen or when the reflectance is high. Therefore, if the real main subject does not meet the predetermined condition, the exposure may not be as expected by the photographer.

  In Patent Document 1, the main light emission amount is calculated based on the reflected light of the subject at the time of pre-light emission. For this reason, when the reflectance of the subject is high or low, the exposure may be different from the original preferable exposure depending on the reflectance of the subject.

  Further, according to the technique described in Patent Document 2, when the main subject is a person and the face of the person is reliably detected, the possibility of good exposure increases. However, when the resolution of the sensor that measures the reflected light during pre-emission is not sufficient for the size of the face area occupied on the imaging screen, the following problem occurs. Even if it is attempted to determine the main light emission amount using only the face area as the light control area, the influence of other areas such as the background of the person cannot be excluded and the exposure may not be good.

  According to the technique described in Patent Document 3, the shooting distance to the subject is calculated from the size of the subject's face, and the light emission amount according to the distance is determined, so that it does not depend on the reflectance of the subject. The possibility that the original preferable exposure can be increased. In general, when performing flash photography, if accurate distance information to the subject can be obtained, the necessary flash emission amount can be calculated from the distance information and the aperture value at the time of photography. Since the calculated flash emission amount is information that does not depend on the reflectance of the subject, it is preferable that information on the distance to the subject can be obtained.

  However, many of the current technologies for detecting a face from a captured image also detect a face image printed on a printed material such as a poster as a human face. Since the face image on the printed material does not always match the size of the real face, there is a high possibility that a large error will occur in the shooting distance calculated from the size of the subject. There are cases where the exposure during shooting is not favorable.

  There is also a concept of obtaining distance information to a subject using an autofocus mechanism or the like equipped in the camera. However, the autofocus mechanism also has various ranging detection errors depending on various conditions, and also includes manufacturing errors in the distance encoder information indicating the position of the distance ring of the photographing lens. Therefore, there is a problem that it is difficult to determine whether the obtained distance information to the subject actually has a small error with respect to the distance to the subject or a large error.

An object of the present invention is to provide a possibility as the imaging device and controls how to gain exposure stably with a reduced influence of the error of good exposure and light emission amount does not depend on the reflectance of the subject.

To achieve the above object, an imaging apparatus according to the present invention is an imaging apparatus capable shooting with emitting means for emitting light to an object, the lens driving information of the photographing lens with the focusing A first acquisition unit that acquires distance information of the subject based on the second acquisition unit, a second acquisition unit that acquires face information of the subject based on an image signal obtained by imaging, and a second acquisition unit; and distance calculating means for calculating the object scene object distance and based on the obtained the face information, the distance information of the object obtained with by the first acquisition means and the subject distance calculated by the calculating means And a light emission amount calculating means for calculating a main light emission amount of the light emitting means .

According to the present invention, good and stable exposure can be obtained.

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

  FIG. 1 is a configuration diagram showing internal configurations of a camera body, an interchangeable lens, and a flash device as an imaging device according to a first embodiment of the present invention.

  In FIG. 1, the camera is a so-called single-lens reflex type capable of exchanging lenses, and an interchangeable lens 2 and a flash device 3 are detachably attached to the camera body 1. The camera body 1 includes a mechanical shutter (hereinafter referred to as shutter) 10, a low-pass filter 11, an image sensor 12, a main mirror 13, a first reflection mirror 14, a second reflection mirror 16, an infrared cut filter 17, and a diaphragm 18. Yes. The camera body 1 further includes a secondary imaging lens 19, a focus detection sensor 20, a focus plate 21, a pentaprism 22, an eyepiece lens 23, a third reflection mirror 24, a condenser lens 25, and a photometric sensor 26. ing.

  The image sensor 12 is composed of an area storage type photoelectric conversion element (for example, CMOS or CCD). The main mirror 13 is a semi-transmissive main mirror. Both the main mirror 13 and the first reflecting mirror 14 are flipped upward from the illustrated position by a drive mechanism (not shown) during photographing. The paraxial imaging plane 15 exemplifies an imaging plane conjugate with the imaging plane of the imaging device 12 by the first reflection mirror 14. The diaphragm 18 has two openings.

  The focus detection sensor 20 is composed of area-storage photoelectric conversion elements (for example, CMOS or CCD), and includes a light receiving sensor unit 20A and a light receiving sensor unit 20B arranged in two areas as shown in FIG. I have. The light receiving sensor unit 20A and the light receiving sensor unit 20B correspond to the two openings of the diaphragm 18, respectively, and are divided into a number of sections. In addition to the light receiving sensor unit 20A and the light receiving sensor unit 20B, the focus detection sensor 20 includes a signal storage unit, a signal processing peripheral circuit, and the like as an integrated circuit on the same chip.

  The configuration from the first reflecting mirror 14 to the focus detection sensor 20 is an image shift method at an arbitrary position in the imaging screen, as described in detail in, for example, Japanese Patent Application Laid-Open No. 9-184965. This makes it possible to detect the focus.

The photometric sensor 26 is composed of a photoelectric conversion element such as a silicon photodiode, for example, and is a sensor for obtaining information related to the luminance of the subject. The photometric sensor 26 includes a light receiving sensor unit 26A divided into a plurality of grids as shown in FIG. In this embodiment, the light receiving sensor section 26A is divided into 35 columns of 7 columns × 5 rows in the light receiving field. The light receiving parts divided into 35 are denoted as PD1 to PD35. In the photometric sensor 26, in addition to the light receiving sensor portion 26A, a signal amplifying portion, a peripheral circuit for signal processing, and the like are built as an integrated circuit on the same chip.

  The focus plate 21, the pentaprism 22, and the eyepiece lens 23 constitute a finder optical system. Of the light beam reflected by the main mirror 13 and diffused by the focus plate 21, a part outside the optical axis is incident on the photometric sensor 26.

  FIG. 4 is a diagram illustrating a corresponding positional relationship between the focus detection position in the imaging screen by the focus detection sensor 20 and the 35 photometric sensors 26 divided into 35 parts. In the present embodiment, focus detection is performed at, for example, three focus detection positions S0 to S2 in the imaging screen. The focus detection position S0 corresponds to the light receiving unit PD18 of the photometric sensor 26. The focus detection position S1 corresponds to the light receiving unit PD16 of the photometric sensor 26. The focus detection position S2 corresponds to the light receiving unit PD20 of the photometric sensor 26. The number of divisions 35 of the light receiving sensor unit 26A in the photometric sensor 26 and the three focus detection positions S0 to S2 are merely examples, and the present invention is not limited thereto.

  Returning to the description of FIG. In the camera body 1, the mount portion 27 is a member for attaching the interchangeable lens 2 to the camera body 1. The contact portion 28 is used for information communication between the camera body 1 and the interchangeable lens 2. The connection portion 29 is a member for attaching the flash device 3 to the camera body 1.

The interchangeable lens 2 includes optical lenses 30 a to 30 e constituting a photographing lens, a diaphragm 31, a contact portion 32 for performing information communication with the camera body 1, and a mount portion 33 for attaching the interchangeable lens 2 to the camera body 1. Yes. The flash device 3 includes a light emitting unit 34 (xenon tube in this example ) , a reflective shade 35, a condensing Fresnel lens 36, a light emission amount sensor (monitor sensor) 37 for detecting the light emission amount of the light emitting unit 34, and the flash device 3. An attachment portion 38 for attaching to the camera body 1 is provided.

  FIG. 5 is a block diagram illustrating a configuration example of an electric circuit of the camera body, the interchangeable lens, and the flash device.

  In FIG. 5, the camera body 1 further includes a control unit 41, a shutter drive unit 42, a signal processing circuit 43, a storage unit 44, a first motor driver 45, a first motor 46, a display 47, a release switch 48, A live view start switch 49 and a storage unit 50 are provided.

The control unit 4 1 controls the entire camera. The control unit 41 is composed of a one-chip microcomputer incorporating an A / D converter 41a, a timer 41b, an arithmetic logic unit (ALU) 41c, a ROM 41d, a RAM 41e, a serial communication port (SPI) 41f, and the like. Further, the control unit 41 executes the processes shown in the flowcharts of FIGS. 6a, 6b, 7 and 8, based on the program stored in the ROM 41d. The ROM 41d stores a later-described LVL0 determination table (FIG. 9) and a W (i) value determination table (FIG. 10).

  The shutter 10, the image sensor 12, the focus detection sensor 20, and the photometry sensor 26 are the same as those illustrated in FIG. Output signals of the focus detection sensor 20 and the photometry sensor 26 are input to the input terminal of the A / D converter 41a of the control unit 41. The shutter drive unit 42 is connected to the output terminal of the control unit 41 and drives the shutter 10.

The signal processing circuit 4 3 controls the imaging device 12 according to an instruction of the control section 41 performs signal processing an image signal output from the imaging device 12 to input while converting A / D, to obtain an image signal. Further, the signal processing circuit 43 extracts features such as the eyes and mouth of the subject (human) from the obtained image signal to detect a human face and obtain face information (face position information and face size information) as face information. It also has a function. Further, the signal processing circuit 43 performs necessary image processing such as compression when recording the obtained image signal in the storage unit 50.

  The storage unit 44 is configured as a DRAM, for example, and is used as a work memory when the signal processing circuit 43 performs various signal processing or as a VRAM when displaying an image on the display unit 47. . The first motor driver 45 is connected to the output terminal of the control unit 41, and based on the control of the control unit 41, the main mirror 13 and the first reflection mirror 14 are up / down, and the shutter 10 is charged (shutter 10 To return to the initial position. The display 47 is composed of a liquid crystal panel, and displays various captured images and the like when the lighting is controlled by the control unit 41.

  The release switch 48 is operated by an operator at the time of shooting. The live view start switch 49 is operated when starting a live view function (a function for performing composition confirmation and focusing while displaying a through image captured by the image sensor 12 on the display 47 in real time). The storage unit 50 is configured as a flash memory or an optical disc, for example, and stores captured image signals.

  The contact portion 28 is in contact with the contact portion 32 of the interchangeable lens 2 and is connected with an input / output signal via the serial communication port 41 f of the control portion 41. Thereby, information communication between the camera body 1 and the interchangeable lens 2 is possible. The connection unit 29 is connected to the connection unit 38 of the flash device 3 and is connected to an input / output signal via the serial communication port 41 f of the control unit 41. Thereby, information communication between the camera body 1 and the flash device 3 is possible.

  The interchangeable lens 2 further includes a lens control unit 51, a second motor driver 52, a second motor 53, a third motor driver 54, a third motor 55, a distance encoder 56, and a zoom encoder 57. The lens control unit 51 includes a one-chip microcomputer incorporating a serial communication port (SPI) 51a, an arithmetic logic unit (ALU) 51b, a ROM 51c, a RAM 51d, a timer 51e, and the like.

  The second motor driver 52 is connected to the output terminal of the lens control unit 51 and drives the second motor 53 for performing focus adjustment based on the control of the lens control unit 51. The third motor driver 54 is connected to the output terminal of the lens control unit 51, and drives a third motor 55 for controlling the diaphragm 31 based on the control of the lens control unit 51.

  The distance encoder 56 is connected to the input terminal of the lens control unit 51, and is the amount of extension of the focus adjustment lens in the interchangeable lens 2 (the amount of driving of the photographing lens accompanying focus adjustment) or after focus adjustment of the focus adjustment lens. The stop position is measured and information about this is output. That is, by obtaining the information of the distance encoder 56, information on the absolute distance to the subject whose focus has been adjusted can be obtained. In the case of an encoder output that outputs the relative driving amount of the focusing lens, it does not provide information on the absolute distance as it is, but a certain reference position such as an infinite end is provided and the relative driving amount from there. If so, it can be converted into information on the absolute distance.

  The zoom encoder 57 is connected to the input terminal of the lens control unit 51, and when the interchangeable lens 2 is a zoom lens, measures the focal length at the time of shooting and obtains focal length information. The contact unit 32 is connected to an input / output signal via the serial communication port 51 a of the lens control unit 51.

  When the interchangeable lens 2 is attached to the camera body 1, the respective contact portions 32 and the contact portions 28 are connected. As a result, the lens control portion 51 of the interchangeable lens 2 performs data communication with the control portion 41 of the camera body 1. Is possible. Information required by the control unit 41 of the camera body 1 is output from the lens control unit 51 to the control unit 41 by data communication. The information includes optical information unique to the lens necessary for focus detection and exposure calculation, information on the absolute distance to the subject measured by the distance encoder 56, and focal length information measured by the zoom encoder 57. Including.

  Information processed by the control unit 41 of the camera body 1 is output from the control unit 41 to the lens control unit 51 by data communication. The information includes focus adjustment information and aperture information obtained as a result of the focus detection and exposure calculation performed by the control unit 41. The lens control unit 51 controls the second motor driver 52 according to the focus adjustment information output from the control unit 41 of the camera body 1 and controls the third motor driver 54 according to the aperture information.

  The flash device 3 further includes a flash controller 61 and a booster 62. The light emitting unit 34 and the light emission amount sensor 37 are the same as those illustrated in FIG. The flash control unit 61 is composed of a one-chip microcomputer incorporating an arithmetic logic unit (ALU), ROM, RAM, A / D converter, serial communication port (SPI) (not shown) and the like. The step-up unit 62 has a function of generating a high voltage of about 300 V necessary for light emission of the light emitting unit 34 and charging the high voltage.

  When the flash device 3 is attached to the camera body 1, the respective connection units 38 and 29 are connected. As a result, the flash control unit 61 of the flash device 3 performs data communication with the control unit 41 of the camera body 1. Is possible. The flash control unit 61 controls the boosting unit 62 according to the communication content from the control unit 41 of the camera body 1 to start / stop the light emission of the light emitting unit 34, and the detected amount of the light emission amount sensor 37 is set to the camera body 1. To the control unit 41.

  Next, the operation of the camera of the present embodiment having the above configuration will be described with reference to FIGS.

  6a and 6b are flowcharts showing a specific operation sequence related to the present invention in the camera.

  6a and 6b, when a power switch (not shown) of the camera is turned on by the operator, the control unit 41 of the camera body 1 becomes operable and this processing is started.

  In step S101, the control unit 41 communicates with the flash control unit 61 of the flash device 3, operates the boosting unit 62, and performs charging to generate a high voltage sufficient for light emission of the light emitting unit 34 (flash). To instruct.

  In step S102, the control unit 41 communicates with the lens control unit 51 of the interchangeable lens 2 to obtain information on various lenses constituting the interchangeable lens 2 necessary for distance measurement and photometry.

  In step S103, the control unit 41 checks whether the live view start switch (LVSW) 49 is turned on by the operator. If the live view start switch 49 is not turned on, the process proceeds to step S104.

  Next, in step S104, the control unit 41 detects face position information indicating the coordinates of the face position of the human subject on the imaging screen stored in the RAM 41e during the previous shooting, and a face size indicating the face size of the human subject. Clear information. The reason is that the face position information and the face size information are effective information when the live view start switch 49 is turned on and the live view operation is started, but otherwise, there is no meaning.

  Next, in step S <b> 105, the control unit 41 outputs a control signal to the focus detection sensor 20, and accumulates signals in the signal accumulation unit associated with focus detection in the focus detection sensor 20. When the signal accumulation is completed, the control unit 41 performs A / D conversion while reading the signal accumulated in the signal accumulation unit of the focus detection sensor 20. Furthermore, the control unit 41 performs various necessary data corrections such as shading correction on each A / D converted digital data.

  In step S106, the control unit 41 inputs lens information and the like necessary for focus detection from the lens control unit 51, and performs imaging based on the lens information and digital data obtained from the focus detection sensor 20. The focus state of each part of the screen is calculated. Further, the control unit 41 determines a region to be focused in the imaging screen from the focus detection positions S0 to S2 (FIG. 4). If there is an area previously designated by the operator using the operation member or the like, it may be followed. The control unit 41 calculates a lens movement amount for focusing according to the focus state in the determined area, and outputs the calculated lens movement amount to the lens control unit 51.

  The lens control unit 51 drives the second motor 53 by outputting a drive signal to the second motor driver 52 so as to drive the focus adjustment lens according to the lens movement amount. As a result, the photographing lens is brought into focus with respect to the subject. By driving the focus adjustment lens, the information measured by the distance encoder 56 changes, and the absolute distance information to the subject whose focus has been adjusted can be known. Therefore, the control unit 41 communicates with the lens control unit 51 to update information on various lenses.

  Next, in step S107, the control unit 41 performs A / D conversion while reading the signals of the light receiving units PD1 to PD35 (FIG. 3) divided into 35 from the photometric sensor 26, and inputs luminance information of each part of the imaging screen. To do. Further, the control unit 41 inputs necessary lens information and the like from the lens control unit 51, corrects luminance information of each part of the imaging screen, and obtains subject luminance information for each light receiving unit of the photometric sensor 26.

  Next, in step S108, the control unit 41 uses the obtained subject luminance information for each light receiving unit of the photometric sensor 26 to determine each light receiving unit of the photometric sensor 26 corresponding to the focus detection portion by the focus detection sensor 20. The brightness of the entire imaging screen is calculated by weighting the brightness information. Based on the luminance information of the entire imaging screen calculated in this way, the control unit 41 determines the charge accumulation time (that is, shutter speed) and aperture value of the imaging device 12 suitable for imaging from a prescribed program diagram (not shown). It is determined and displayed on the display 47. When one of the shutter speed and the aperture value is preset in advance, the other factor that provides good exposure is determined in combination with the preset value.

  The exposure value based on the apex value between the determined shutter speed and aperture value is referred to as EVT. The exposure value EVT is expressed by the following formula.

EVT = Tv + Av
Here, Tv is the apex value of the shutter speed, and Av is the apex value of the aperture value.

  Next, in step S109, the control unit 41 waits for the release switch 48 to be turned on by the operator. If the release switch 48 is not turned on, the process returns to step S102. If the release switch 48 is turned on, the process proceeds to step S117.

  On the other hand, if the live view start switch 49 is turned on in step S103, the process proceeds to step S110. In step S <b> 110, the control unit 41 drives the first motor 46 by outputting a control signal to the first motor driver 45, and flips the main mirror 13 and the first reflection mirror 14 upward.

  Next, in step S111, the control unit 41 outputs a control signal to the shutter drive unit 42 to open the shutter 10. As a result, a light beam from the photographing lens is incident on the image sensor 12 and imaging is possible. Subsequently, the control unit 41 instructs the signal processing circuit 43 to perform an imaging operation with the imaging element 12. When the imaging operation is started, the control unit 41 performs control so that the obtained captured image is displayed on the display unit 47. Thus, the live view operation is started.

  Next, in step S112, the control unit 41 performs exposure (AE) control and white balance (WB) from the captured image data so that the brightness and color of the live view image displayed on the display device 47 are appropriate. ) Get control data. Further, the control unit 41 corrects the charge accumulation time and color processing of the image sensor 12 based on the obtained data. An exposure value EVT at the time of actual imaging is also calculated from the exposure control data. Exposure control data such as shutter speed and aperture value is calculated as necessary in the same manner as in step S108.

  Next, in step S <b> 113, the control unit 41 performs face detection processing from the captured image by the signal processing circuit 43. In face detection processing, as described in Japanese Patent Application Laid-Open No. 2005-184508, feature edges of eyes and mouth are extracted from image data to detect the position of a person's face and further include eyes and mouth. The contour is detected, the position of the center of gravity is obtained, and the luminance of the region in the contour is calculated. Further, face position information in the imaging screen is obtained based on the calculated barycentric position, and face size information is obtained from the contour information.

  Next, in step S114, the control unit 41 obtains the face position information and face size information obtained by the signal processing circuit 43, and stores them in the RAM 41e. The face position information may be x-coordinate and y-coordinate with a predetermined point such as the center or the upper left corner in the imaging screen as the origin. Further, the face size information may be data indicating the radius of a circle centering on the face position information or length data of one side of the square as data indicating the range in which the face area extends.

  Next, in step S115, the control unit 41 waits for the release switch 48 to be turned on by the operator. If the release switch 48 is not turned on, the process returns to step S112, and the processes of steps S112 to S114 are repeated. If the release switch 48 is on, the process proceeds to step S116.

  Next, in step S116, the control unit 41 outputs a control signal to the shutter drive unit 42, thereby closing the shutter 10 and ending the live view operation. Subsequently, the control unit 41 drives the first motor 46 by outputting a control signal to the first motor driver 45, and once lowers the main mirror 13 and the first reflecting mirror 14 from the flip-up state. The shutter 10 is charged.

  Next, in step S117, the control unit 41 performs A / D conversion while reading the signals of the light receiving units PD1 to PD35 divided into 35 from the photometric sensor 26, and immediately before pre-emission (preliminary emission) of each part of the imaging screen. Enter brightness information. Here, the luminance information (luminance value) immediately before the pre-emission for each light receiving unit of the photometric sensor 26 is referred to as P (i). Subsequently, the control unit 41 communicates with the flash control unit 61 to instruct pre-emission of the light emitting unit 34 (flash).

  Accordingly, the flash control unit 61 causes the light emitting unit 34 to emit light based on the output signal of the light emission amount sensor 37 so that the light emitting unit 34 emits light for a preset pre-emission amount. In order to obtain the luminance information of the subject during the pre-emission, the control unit 41 performs A / D conversion while reading the signals of the light receiving units PD1 to PD35 divided into 35 from the photometric sensor 26. The luminance information at the time of pre-emission of each part of the imaging screen is input. Here, luminance information (luminance value) at the time of pre-emission for each light receiving unit of the photometric sensor 26 is referred to as H (i). Here, i is 1 to 35 corresponding to each of the 35 light receiving portions.

  Next, in step S118, the control unit 41 performs a calculation to determine the main light emission amount (main light emission gain) of the light emitting unit 34 (flash). Specific calculation processing will be described later with reference to the flowchart of FIG.

  Next, in step S119, the control unit 41 drives the first motor 46 by outputting a control signal to the first motor driver 45, and flips the main mirror 13 and the first reflection mirror 14 upward. Subsequently, the control unit 41 outputs the aperture value information calculated in step S <b> 107 to the lens control unit 51 of the interchangeable lens 2.

  The lens control unit 51 drives the third motor 55 by outputting a control signal to the third motor driver 54 so as to drive the diaphragm 31 according to the diaphragm value information. As a result, the photographing lens is brought into a narrowed state.

  In step S120, the control unit 41 outputs a control signal to the shutter driving unit 42 to open the shutter 10. As a result, a light beam from the photographing lens is incident on the image sensor 12 and imaging is possible. Subsequently, the control unit 41 instructs the signal processing circuit 43 to set the charge accumulation time of the image sensor 12 according to the shutter time calculated in step S <b> 107 and perform imaging by the image sensor 12. . In addition, the control unit 41 gives a light emission instruction of the light emitting unit 34 (flash) to the flash control unit 61 of the flash device 3 in synchronization with the imaging timing.

  The flash control unit 61 emits the light emitting unit 34 based on the output signal of the light emission amount sensor 37 so that the light emission amount corresponds to the main light emission amount (main light emission gain) calculated in step S118 according to the light emission instruction. Let Thereby, imaging with flash emission is performed. When the imaging is completed, the control unit 41 outputs a control signal to the shutter drive unit 42 to place the shutter 10 in a light-shielding state. Thereby, the light beam from the photographing lens with respect to the image sensor 12 is blocked.

  Next, in step S <b> 121, the control unit 41 outputs information to the lens control unit 51 of the interchangeable lens 2 so as to open the diaphragm 31. The lens control unit 51 drives the third motor 55 by outputting a control signal to the third motor driver 54 so as to drive the diaphragm 31 according to this information. As a result, the photographing lens is in a fully open state. Furthermore, the control unit 41 drives the first motor 46 by outputting a control signal to the first motor driver 45, and lowers the main mirror 13 and the first reflection mirror 14.

  Next, in step S122, the control unit 41 reads the captured image information from the image sensor 12 while performing A / D conversion, and instructs the signal processing circuit 43 to perform necessary correction processing and interpolation processing.

  Next, in step S123, the control unit 41 instructs the signal processing circuit 43 to perform white balance adjustment on the captured image information. Specifically, in the captured image information, one screen is divided into a plurality of areas, and the white area of the subject is extracted from the color difference signal for each area. Further, the white balance adjustment is performed by correcting the gain of the red channel and the blue channel of the entire imaging screen based on the extracted white region signal.

  In step S <b> 124, the control unit 41 instructs the signal processing circuit 43 to compress and convert the captured image information subjected to white balance adjustment into a recording file format and store it in the storage unit 44. In steps S101 to S124, a series of shooting sequences is completed.

  Next, calculation processing for determining the main light emission amount (main light emission gain) of the light emitting unit 34 (flash) performed in step S118 of FIG. 6B will be described with reference to the flowchart of FIG.

  7 and 8 are flowcharts showing details of calculation processing for determining the main light emission amount (main light emission gain) of the light emitting unit.

  7 and 8, in step S151, the control unit 41 determines the luminance value P (i) immediately before the pre-emission and the luminance value H (i) during the pre-emission for each photometric area (photometric area) of the photometry sensor 26. ), The luminance value (subject reflected light amount) D (i) for only the reflected light during pre-emission is calculated. Since the luminance value P (i) immediately before the pre-light emission and the luminance value H (i) at the time of the pre-light emission are values in the compression system, respectively, P (i) and H (i) The power is expanded by taking the power, and then the difference is taken and the difference value is logarithmically compressed.

D (i) = log ₂ (2 ^{H (i)} −2 ^{P (i)} )
Here, i is 1 to 35 corresponding to each light receiving portion (photometric area) of the photometric sensor 26 divided into 35.

  Next, in step S152, the control unit 41 uses the luminance value P (i) immediately before the pre-light emission and the luminance value H (i) at the time of the pre-light emission for each photometry area of the photometry sensor 26 as shown in the following equation. The luminance value ratio R (i) is calculated.

R (i) = H (i) -P (i)
Since the luminance value P (i) immediately before the pre-emission and the luminance value H (i) at the time of the pre-emission are values in the compression system, taking this difference is equivalent to taking the ratio of the luminance values. .

  The reason for obtaining the ratio of the luminance values is that, as described in Japanese Patent Application Laid-Open No. 2005-275265, the photometric area in which the ratio of the luminance values matches in each photometric area of the photometric sensor 26 divided into 35 is the subject. This is because it can be regarded as a photometric area with the same distance.

  Next, in step S153, the control unit 41 calculates predetermined values LVL0 and LVL1 from the information regarding the distance of the subject as shown by the following equation. LVL0 is as follows from the information of the distance encoder 56 (information D relating to the object distance to the subject) obtained from the lens control unit 51 in step S102 or S106 and the information C2 relating to the amount of emitted light during pre-emission. To calculate. That is, the calculation is performed in consideration of the reflection luminance in the case of a subject having a standard reflectance at the distance.

  LVL0 is determined to be slightly higher than the reflection luminance of the subject with a standard reflectance in the information D (hereinafter, abbreviated as distance information D) regarding the object distance to the subject. In consideration of the fact that the distance information D actually has some errors, LVL0 is increased by an amount corresponding to the error, and the reflected light at the time of pre-emission in the subject having the actual standard reflectance is LVL0. This is to prevent the height from becoming higher.

LVL0 = −log ₂ (D) × 2 + C2
On the other hand, LVL1 is determined by subtracting C3 from LVL0. C3 is determined in consideration of an error of the distance information D and the like so that the reflected light at the time of pre-emission of the subject having an actual standard reflectance does not fall below LVL1.

LVL1 = LVL0-C3
As described above, the following calculation for determining the flash main light emission amount is performed on the assumption that the reflected light during the pre-emission of the subject normally falls between the predetermined values LVL0 and LVL1 from the distance information D.

  In the case of a single-lens reflex camera with interchangeable lenses, the distance information D may not be obtained because the distance encoder 56 is not provided depending on the lens attached to the camera body. Here, a calculation method of the predetermined values LVL0 and LVL1 when the lens is not equipped with the distance encoder 56 will be described.

  First, LVL0 is determined with reference to the LVL0 determination table (table1) shown in FIG. 9 based on the focal length information of the taking lens.

LVL0 = table1 (f)
The LVL0 determination table is a table showing the correspondence between the focal length (f) of the photographic lens and LVL0.

  For example, if the focal length (f) of the photographic lens is 28 mm (f <40 mm), the reflection luminance (standard reflected light at 0.5 m) when a subject having a standard reflectance is located at a distance of 0.5 m. LVL0. In general, when photographing using a photographing lens having a focal length of 28 mm, the frequency of photographing a subject at a short distance of 0.5 m is extremely low. Becomes lower than LVL0.

  Similarly, the LVL0 determination table in FIG. 8 is configured based on the idea that the reflection luminance is LVL0 when an object with a standard reflectance is located at a distance of 0.8 m in the case of a photographing lens with a focal length of 50 mm. Has been. Since it is more reasonable to divide the focal length of the photographic lens in a certain amount of steps, the focal length is divided as such in the LVL0 determination table.

  On the other hand, LVL1 when distance information D is not obtained is calculated by subtracting C1 from LVL0. As a rule of thumb, C1 is determined so that the amount of pre-reflected light from the subject does not fall below LVL1. For example, when flash photography is performed with a photographing lens having a focal length of 50 mm, if the probability of photographing farther than 6.4 m from the subject is extremely low, the subject is compared to the case where the distance is 0.8 m when determining LVL0. Since the reflected light from the light source is 6 steps lower, C1 is set to 6.

LVL1 = LVL0-C1
Both LVL0 and LVL1 are values in the compression system.

  Next, in step S154, the control unit 41 extracts an area where the luminance value D (i) is between the predetermined values LVL0 and LVL1 from the 35 divided photometry areas in the photometry sensor 26. As a result, the luminance value D (i) is abnormally high due to specular reflection from a specular object such as glass, or because the distance is so far that the flash light of the light emitting unit 34 does not reach. Photometric areas where D (i) is very low are excluded. As a result, a photometric area where the main subject is likely to exist is extracted.

  Note that the value of the luminance value H (i) at the time of pre-light emission is not much different from the value of the luminance value D (i) (because the luminance value P (i) immediately before the pre-light emission is often small), In step S154, the luminance value H (i) at the time of pre-emission may be used instead of the luminance value D (i).

  Next, in step S155, the control unit 41 selects the reference area as follows because the subject closest to the extracted photometric area is likely to be the main subject. That is, the luminance value P (i) (first luminance value) immediately before the pre-light emission (before the preliminary light emission operation) and the luminance value H (i) (second luminance) at the time of pre-light emission (during the preliminary light emission operation). The photometric area where the ratio R (i) to the luminance value is the maximum value is selected as the reference area. The value of R (i) in the reference area is referred to as a reference value BaseR (reference ratio value), and a photometric area in which the values of the reference values BaseR and R (i) indicate the same value is referred to as a main subject area. To do.

  Next, in step S156, the control unit 41 determines the difference RR () between the ratio R (i) of the luminance value and the reference value BaseR as shown in the following equation in all photometric areas of i = 1 to 35 in the photometric sensor 26. i) is calculated.

RR (i) = baseR−R (i)
Since both the luminance value ratio R (i) and the reference value BaseR are values in the compression system, RR (i) calculates the ratio of R (i) in the reference area and R (i) in the other photometric areas. Will be. The photometric area in which the value of RR (i) is small is a photometric area in which the subject exists at a distance approximately equivalent to the subject in the photometric area that is assumed to be the main subject area and has the reference value BaseR.

  On the other hand, the photometric area where the value of RR (i) increases in the positive direction is assumed to be the main subject area, and there is a subject that is farther away than the subject in the photometric area that has the reference value BaseR. This is a photometric area that can be regarded as Conversely, the photometric area in which the value of RR (i) increases in the negative direction is a photometric area that is assumed to be the main subject area and can be regarded as being closer to the subject in the photometric area having the reference value BaseR. is there.

  That is, such a photometric area is considered to be a photometric area in which an object has an obstacle in front of it other than the main subject, or a photometric area in which specular reflection by a mirror surface such as glass occurs and an abnormally high amount of reflected light is obtained. It is done.

  Next, in step S157, the control unit 41 determines the weighting coefficient W (i) according to RR (i) calculated in all photometric areas of i = 1 to 35 in the photometric sensor 26. Specifically, W (i) is obtained from the value of RR (i) in each photometric area with reference to the W (i) value determination table (table2) shown in FIG.

W (i) = table2 (RR (i))
The W (i) value determination table is a table showing the correspondence between RR (i) and W (i).

  According to the W (i) value determination table, the photometric area in which the value of RR (i) becomes the reference value BaseR is given the maximum value 12 on weighting as W (i). A photometric area in which the value of RR (i) is the same as or very close to the reference value BaseR is given a higher value for W (i). This is because such a region is regarded as a main subject region or a subject having substantially the same distance as the main subject.

  As the absolute value of the RR (i) value increases from 0, the weighting coefficient W (i) given to the photometric area gradually decreases. This is because there is a high possibility that the subject area is different from the subject in the photometry area assumed to be the main subject.

  In this way, the light emission amount is calculated in the subsequent steps by giving a weighting coefficient according to the distance to the subject existing in each photometric area. As a result, even when the main subject position in the imaging screen is moved every time shooting is performed, or when the same scene is shot with a slightly different composition, the same amount of main light emission can be calculated. It is possible to prevent different exposure results from being obtained.

  Next, in step S158, the control unit 41 performs weighting calculation of the reflected light of the subject in all photometric areas of i = 1 to 35 in the photometric sensor 26 as shown by the following equation.

AVE = Σ (D (i) × W (i)) / ΣW (i)
By this weighting calculation, the weighted average value AVE of the reflected light of the entire imaging screen in which the weighting is larger in the metering area that is assumed to be the subject having the same distance as the metering area regarded as the main subject area is calculated.

  Next, in step S159, the control unit 41 checks whether information on the distance encoder 56 is obtained from the lens control unit 51 in step S153. As in this embodiment, the interchangeable lens 2 is equipped with a distance encoder 56, and distance information D (corresponding to the amount of extension of the focus adjustment lens) measured by the distance encoder 56 as information on the absolute distance to the subject can be obtained. If yes, the process proceeds to step S160.

  Next, in step S160, the control unit 41 calculates a predetermined value LVL2 (reference reflected light amount) from the distance information D as shown in the following equation. LVL2 is a subject having a standard reflectance at the distance from distance information D measured by the distance encoder 56 obtained from the lens control unit 51 and information C4 on the amount of emitted light at the time of pre-emission, as in step S153. In consideration of the reflection luminance in the case of.

  LVL2 is determined so as to substantially match the reflection luminance of the subject having a standard reflectance in the distance information D. This is because when the distance information D matches the actual distance (actual distance) to the subject, an accurate main light emission amount can be calculated.

LVL2 = −log ₂ (D) × 2 + C4
Next, in step S161, the control unit 41 checks whether face position information and face size information are available. When the live view operation is started and the process of step S114 is executed, face position information and face size information are available. Otherwise, the face position information and the face size information are not obtained because the face position information and the face size information are cleared in step S104. If face position information and face size information are available, the process proceeds to step S162.

  Next, in step S162, the control unit 41 determines the object distance to the subject based on the face size information detected by the signal processing circuit 43 and the focal length information of the photographing lens obtained from the lens control unit 51. Df is calculated. Here, assuming that the focal length information of the photographing lens is FL, the detected face size information is Wf, and the conversion coefficient determined by the actual human face size is K1, the object distance Df is expressed by the following equation. Is calculated by

Df = FL × K1 ÷ Wf
The actual size of a person's face naturally depends on age and individual differences, but according to the collection of human body size data for design by the Institute of Biotechnology, the average Japanese head width is 162 mm. Has been. On the other hand, according to Humancale Published by The MIT Press, the average head width of an American (male) is 155 mm. From such statistical information, the conversion coefficient K1 may be determined on the assumption that the face size (width) of an actual person is 150 to 160 mm.

  If the face size information is less than or equal to a predetermined value, the detection accuracy may be low. Also, if the face size information is greater than or equal to a predetermined value and the face position information is located in the periphery of the image capture screen, there is a possibility that the face protrudes from the image capture screen. There may be a large error in accuracy. In such a case, for example, Df = 0 is set without calculating Df.

  Next, in step S163, the control unit 41 calculates a ratio DS between the distance information D measured by the distance encoder 56 obtained from the lens control unit 51 and the object distance Df calculated in step S162 by the following equation. To do.

DS = D ÷ Df
Since the above calculation cannot be performed when Df = 0, a fixed value greater than a predetermined value such as DS = 255 is given.

  Next, in step S164, the control unit 41 checks whether the value of the ratio DS is within a predetermined value. A case where the ratio DS is within a range of, for example, 0.9 to 1.1 is set within a predetermined value. That is, the distance information D measured by the distance encoder 56 matches the object distance Df calculated from the face size information with an accuracy within 10%. When the value of the ratio DS is within the predetermined value, it is considered that the information D relating to the distance to the subject has a very small error with respect to the distance to the actual subject (shooting distance), and thus the process proceeds to step S165. .

  Next, in step S165, the control unit 41 calculates a correction value DC of the reflected light amount based on the distance information D by the following equation.

DC = (LVL2-AVE) × 0.7
Here, LVL2 is a reference reflected light amount calculated from the distance information D calculated in step S160, and AVE is a weighted average value of all photometric areas during pre-emission calculated in step S158.

  When the value of the ratio DS is not within the predetermined value in step S164, the control unit 41 regards that the distance information D has some error with respect to the shooting distance to the actual subject, and proceeds to step S166. move on. If face position information and face size information are not available in step S161, it cannot be determined whether the distance information D has a small or large error with respect to the actual distance to the subject. Therefore, the control unit 41 regards that there is some error as described above, and proceeds to step S166.

  Next, in step S166, the control unit 41 calculates a correction value DC of the reflected light amount based on the distance information D by the following equation.

DC = (LVL2-AVE) × 0.3
Here, LVL2 is a reference reflected light amount calculated from the distance information D calculated in step S160, and AVE is a weighted average value of all photometric areas during pre-emission calculated in step S158.

  If the interchangeable lens 2 is not equipped with the distance encoder 56 and the information D of the distance encoder 56 as the distance information to the subject cannot be obtained in step S159, the process proceeds to step S167. In step S167, the control unit 41 sets DC = 0 because it cannot calculate the correction value DC of the reflected light amount based on the distance information D to the subject.

  When one of the processes in step S165, step S166, and step S167 is completed, the process proceeds to step S168. In step S168, the control unit 41 reduces the emission amount G of the main light emission from the EVT determined in step S108 or step S112, the AVE calculated in step S158, and the DC calculated in any of steps S165 to S167. Operate with an expression.

G = EVT-AVE-DC
G is a relative value of the main light emission with respect to the flash light emission amount by the light emitting unit 34 during the pre-light emission.

  When the process proceeds from step S165 to step S168, 70% of the difference between the reference reflected light amount LVL2 calculated from the distance information D to the subject and the weighted calculation value AVE of all photometric areas at the time of pre-flash is the correction amount DC. It has become. In this case, the information D of the distance encoder 56 as the distance information to the subject is determined to be fairly accurate. Therefore, the ratio of the main light emission amount G depending on the reference reflected light amount LVL2 calculated from the distance information D is 70%, and the ratio depending on the weighted calculation value AVE of all the photometry areas at the time of pre-light emission is 30%. As a result, the main light emission amount G is determined by placing a specific gravity of 70% on the information D of the distance encoder 56.

  When the process proceeds from step S166 to step S168, 30% of the difference between the reference reflected light amount LVL2 calculated from the distance information D to the subject and the weighted calculation value AVE of all photometry areas at the time of pre-flash is the correction amount DC. It has become. In this case, the information D of the distance encoder 56 as the distance information to the subject is determined to have some error. Therefore, the ratio of the main light emission amount G depending on the reference reflected light amount LVL2 calculated from the distance information D is 30%, and the ratio depending on the weighted calculation value AVE of all photometry areas at the time of pre-light emission is 70%. As a result, the main light emission amount G is determined by placing a specific gravity of 70% on the weighted calculation value AVE of all photometry areas during pre-flash.

  When the process proceeds from step S167 to step S168, there is no information D of the distance encoder 56 as distance information to the subject. Accordingly, the correction value DC of the reflected light amount based on the distance information D to the subject is zero. As a result, the main light emission amount G is determined by placing a specific gravity of 100% on the weighted calculation value AVE of all photometry areas during pre-flash.

  The value of the main light emission amount G is transmitted by communication from the control unit 41 of the camera body 1 to the control unit 61 of the flash device 3, and the main light emission by the light emitting unit 34 is performed based on the main light emission amount in step S <b> 120. Thereby, desired flash imaging is performed.

  In step S164, the predetermined value is set to 0.9 or more and within 1.1, the coefficient for calculating the correction value DC is set to 0.7 in step S165, and the correction value DC is calculated in step S166. The coefficient to be set to 0.3 is an example. The present invention is not limited to these numerical values.

  As described above, according to the present embodiment, the following effects are obtained. In a situation where it is possible to determine that the error in the absolute distance information to the subject obtained from the camera focus adjustment result is small, the light emission amount of the flash unit 3 is determined by weighting the distance information. Thereby, it is possible to obtain a good exposure regardless of the reflectance of the subject. On the other hand, in a situation where it can be determined that the error in the absolute distance information to the subject obtained from the focus adjustment result is large, the light emission amount of the flash unit 3 is determined by weighting the photometric value at the time of pre-light emission. Thereby, it becomes possible to obtain a stable exposure by reducing the influence of the error in the amount of light emission generated from the error in the distance information to the subject.

[Other Embodiments]
The object of the present invention is achieved by executing the following processing. That is, a storage medium in which a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. This is the process of reading the code.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above-described embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, a case where the functions of the above-described embodiment are realized by the following processing is also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

It is a block diagram which shows the internal structure of the camera main body, interchangeable lens, and flash apparatus as an imaging device which concerns on the 1st Embodiment of this invention. It is a figure which shows the structural example of the sensor for focus detection of a camera. It is a figure which shows the structural example of the sensor for photometry of a camera. It is a figure which shows the corresponding positional relationship of the focus detection position in the imaging screen by a focus detection sensor, and the sensor for photometry divided into 35. It is a block diagram which shows the structural example of the electric circuit of a camera main body, an interchangeable lens, and a flash apparatus. It is a flowchart which shows the specific operation | movement sequence in connection with this invention in a camera. It is a flowchart which shows the specific operation | movement sequence in connection with this invention in a camera. It is a flowchart which shows the detail of the arithmetic processing which determines the main light emission amount (main light emission gain) of a light emission part. It is a flowchart which shows the continuation of FIG. It is a figure which shows the example of the table for LVL0 determination. It is a figure which shows the example of the table for W (i) value determination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera body 2 Interchangeable lens 3 Flash apparatus 12 Image sensor 26 Photometric sensor 34 Light emission part 41 Control part 43 Signal processing circuit 56 Distance encoder

Claims (13)

An imaging apparatus capable shooting with emitting means for emitting light to an object,
First acquisition means for acquiring distance information of the subject based on lens drive information of the photographing lens accompanying the focus adjustment;
Second acquisition means for acquiring face information of the subject based on an image signal obtained by imaging;
And distance calculating means for calculating the object scene object distance and based on the said face information acquired by the second acquisition unit,
A light emission amount calculation means for calculating a main light emission amount of the light emission means based on the distance information of the subject obtained by the first acquisition means and the subject distance calculated by the distance calculation means. An imaging apparatus characterized by the above.   Metering means for metering the brightness of the subject;
  The light emission amount calculating means is based on at least one of a first value based on the photometric result of the photometric means and a second value based on the subject distance information obtained by the first acquiring means. Based on the subject distance based on the subject distance information obtained by the first acquisition means and the subject distance calculated by the distance calculation means, the main light emission amount of the light emitting means is calculated. The imaging apparatus according to claim 1, wherein at least one of the weighting of the first value and the weighting of the second value in the main light emission amount calculation is changed.   The light emission amount calculation means calculates the main light emission amount calculation of the light emission means as the subject distance based on the subject distance information obtained by the first acquisition means is closer to the subject distance calculated by the distance calculation means. The imaging apparatus according to claim 2, wherein the weighting of the second value is increased.   The light emission amount calculating means has a ratio of a subject distance based on the subject distance information obtained by the first obtaining means and a subject distance calculated by the distance calculating means within a predetermined range. 3. The imaging apparatus according to claim 2, wherein the weighting of the second value in the main light emission amount calculation of the light emitting unit is made larger than in the case where the ratio is out of the predetermined range.   The light emission amount calculation means, when the face information is not acquired by the second acquisition means, the second value in the main light emission amount calculation of the light emission means than when the ratio is within the predetermined range. The imaging apparatus according to claim 4, wherein the weighting of the image pickup device is reduced.   The light emission amount calculation means is more effective in the light emission means when the distance information of the subject can be acquired by the first acquisition means when the distance information of the subject is not acquired by the first acquisition means. The imaging apparatus according to claim 2, wherein the weight of the second value in the main light emission amount calculation is reduced.   The light emission amount calculation means calculates the main light emission amount calculation of the light emission means as the subject distance based on the subject distance information obtained by the first acquisition means is closer to the subject distance calculated by the distance calculation means. The imaging apparatus according to claim 2, wherein the weighting of the first value is reduced.   The light emission amount calculating means has a ratio of a subject distance based on the subject distance information obtained by the first obtaining means and a subject distance calculated by the distance calculating means within a predetermined range. 7. The weighting of the first value in the main light emission amount calculation of the light emitting means is made smaller than in the case where the ratio is out of the predetermined range. The imaging device described.   The light emission amount calculation means, when the face information is not acquired by the second acquisition means, the first value in the main light emission amount calculation of the light emission means than when the ratio is within the predetermined range. The imaging apparatus according to claim 8, wherein the weighting of the imaging apparatus is increased.   The light emission amount calculation means is more effective in the light emission means when the distance information of the subject can be acquired by the first acquisition means when the distance information of the subject is not acquired by the first acquisition means. 10. The imaging apparatus according to claim 2, wherein weighting of the first value in the main light emission amount calculation is increased.   The distance calculation unit calculates a subject distance based on the face information acquired by the second acquisition unit and the focal length information of the imaging device. The imaging device according to item. The face information, the imaging apparatus according to any one of claims 1 to 11, characterized in that said a face size information indicating the size of the face of a person is the subject of the imaging screen of the imaging apparatus . A method for controlling an imaging apparatus capable of photographing using a light emitting means for emitting light to a subject,
A first acquisition step of acquiring distance information of the subject based on lens drive information of the photographing lens accompanying focus adjustment;
A second acquisition step of acquiring face information of the subject based on an image signal obtained by imaging;
A distance calculation step of calculating the object scene object distance and based on the said face information acquired in the second acquisition step,
A light emission amount calculation step of calculating a main light emission amount of the light emitting means based on the distance information of the subject obtained in the first acquisition step and the subject distance calculated in the distance calculation step. A control method characterized by the above.

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