JP2013041002A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera which accurately measures an amount of light reflected from a subject during preliminary light emission.SOLUTION: A camera includes: a control unit which performs preliminary light emission for causing a flash device to emit light prior to shooting; an optical sensor unit including multiple light receiving elements which perform first light measurement for measuring fixed light by accumulating electric charges for a first accumulation time prior to the preliminary light emission, and second light measurement for measuring light reflected from a subject according to the preliminary light emission by accumulating electric charges for a second accumulation time; an estimation unit which estimates, from a result of the first light measurement, whether or not an amount of electric charges accumulated with the fixed light at the optical sensor unit upon the second light measurement becomes greater than a predetermined amount; a sensitivity setting unit which sets, if the estimation unit estimates the amount of electric charges accumulated becomes greater than the predetermined amount, light receiving sensitivity of the optical sensor unit upon the second light measurement to light receiving sensitivity which allows the amount of electric charges accumulated with the fixed light to become not greater than the predetermined amount; and a calculation unit which calculates, from a result of the second light measurement, an amount of light emitted from the flush device during shooting.

Description

  The present invention relates to a camera.

  2. Description of the Related Art Conventionally, a technique for determining a light emission amount of a flash device at the time of photographing is known. For example, the camera described in Patent Document 1 emits a flash device with a relatively small amount of light before photographing as so-called preliminary light emission, and measures the light reflected from the subject accompanying the light emission, thereby emitting light from the flash device at the time of photographing. Determine the amount.

JP 2006-317664 A

  The camera described in Patent Document 1 has a problem that the amount of light reflected from a subject cannot be accurately measured when preliminary light is emitted when the amount of steady light is large.

  According to the first aspect of the present invention, there is provided a camera capable of controlling a flash device that performs flash emission, a controller that performs preliminary light emission for causing the flash device to emit light prior to photographing, and a first accumulation time prior to preliminary light emission. A first photometry that measures steady light by accumulating charges only, and a second photometry that measures the reflected light from a subject associated with preliminary light emission by accumulating charges for a second accumulation time. A photosensor unit having a light receiving element, a prediction unit that predicts whether or not the charge accumulation amount due to the steady light of the photosensor unit in the second photometry is greater than a predetermined amount from the photometry result of the first photometry, and a prediction unit A sensitivity setting unit configured to set the light receiving sensitivity of the photosensor unit in the second photometry to a light receiving sensitivity at which the charge accumulation amount by the steady light is equal to or less than a predetermined amount when the charge accumulation amount is predicted to be larger than the predetermined amount; Two photometry The results is a camera, characterized in that it comprises a calculator for calculating a light emission amount of the flash device at the time of shooting.

  According to the present invention, it is possible to accurately measure the amount of light reflected from a subject during preliminary light emission.

It is sectional drawing which shows the lens-interchangeable camera system to which this invention is applied. 3 is a front view showing a partial configuration of an area sensor 101. FIG. It is a figure explaining block formation for exposure calculation. It is a figure explaining block formation for TTL light control calculation. 6 is a flowchart of a photographing process using the flash device 103. 6 is a diagram showing a charge accumulation pattern by the area sensor 101. FIG. FIG. 10 is a diagram illustrating a shooting range and a range for determining the light emission amount of the flash device 103 at the time of shooting in the second calculation mode.

(First embodiment)
FIG. 1 is a cross-sectional view showing an interchangeable lens type camera system to which the present invention is applied. The camera 1 is a so-called single-lens reflex digital camera that includes a camera body 100 and an interchangeable lens 200 that can be attached to and detached from the camera body 100.

  The camera body 100 is configured so that the flash device 103 can be attached. The flash device 103 is connected to the camera body 100 via an electrical contact and is controlled by the camera body 100. The flash device 103 may not be attachable to the camera body 100. For example, it may be installed at a position away from the camera body 100 and controlled from the camera body 100 by optical communication or wireless communication. Further, the camera body 100 may incorporate the flash device 103.

  The interchangeable lens 200 is provided with an imaging optical system 201 composed of a plurality of lenses and a stop 202 having an opening. The light flux from the subject passes through the imaging optical system 201 and the aperture 202 and enters the camera body 100. In FIG. 1, the imaging optical system 201 is illustrated as if constituted by two lenses, but it may be constituted by any number of lenses. In FIG. 1, the stop 202 is provided behind the imaging optical system 201 (as viewed from the subject). However, as is well known, the stop 202 may be provided in front of the imaging optical system 201. It may be inside the imaging optical system 201 (between lenses).

  The camera body 100 includes an image sensor 116 such as a CCD or CMOS that captures a subject image. The image sensor 116 is arranged so that the imaging surface coincides with the planned focal plane of the imaging optical system 201. A mechanical shutter 115 that controls exposure of the image sensor 116 is provided in the vicinity of the imaging surface of the image sensor 116.

  A quick return mirror 111 is installed between the imaging optical system 201 and the imaging surface of the imaging element 116 in the camera body 100. At the time of non-photographing, the quick return mirror 111 is present at a position where the subject light is reflected upward of the camera body 100 (position indicated by a solid line in FIG. 1). At this time, the subject light incident on the camera body 100 is diffused by the focusing screen 112, passes through the pentaprism 113 (pentagonal roof prism), and then travels toward the eyepiece 114. The photographer can visually recognize the subject image through the eyepiece lens 114. Part of the subject light transmitted through the pentaprism 113 goes to the area sensor 101 (detailed later) provided in the vicinity.

  The arithmetic control device 102 is a device including a microprocessor and its peripheral circuits, and controls each part of the camera body 100 and the interchangeable lens 200. The arithmetic and control unit 102 controls each of these units by reading and executing a predetermined control program stored in advance in a storage medium (not shown).

  When a release switch (not shown) is fully pressed, the arithmetic control device 102 performs photographing control. At this time, the arithmetic and control unit 102 moves the quick return mirror 111 to a retracted position (a position indicated by a broken line in FIG. 1) that does not block the subject light, and then the diaphragm 202 and the mechanical shutter 115 based on the previous exposure calculation result. To control.

  Further, the arithmetic and control unit 102 performs a TTL (through the lens) dimming operation when the release switch is fully pressed when the flash device 103 that irradiates the subject with the photographing auxiliary light is permitted to emit light. Then, shooting control is performed. In the TTL dimming operation, the accumulation operation of the area sensor 101 is performed in accordance with the preliminary light emission of the flash device 103, and the TTL dimming calculation is performed based on the signal obtained by the accumulation operation. The arithmetic control device 102 controls the main light emission amount of the flash device 103 based on the TTL dimming calculation result.

  That is, when the flash device 103 is permitted to emit light, the arithmetic and control unit 102 first causes the flash device 103 to perform preliminary light emission. Then, the amount of light reflected from the subject by preliminary light emission is measured, and the light emission amount (main light emission amount) at the time of photographing is determined from this reflected light amount.

(Description of area sensor 101)
FIG. 2 is a front view showing a partial configuration of the area sensor 101. The area sensor 101 includes a plurality of pixels (photoelectric conversion elements) 40 arranged in a matrix, and the light receiving range thereof is substantially equal to the imaging range of the imaging element 116. The number of pixels of the area sensor 101 is about 100,000 pixels, for example. Each pixel 40 is provided with any one of red (R), green (G), and blue (B) color filters to form a Bayer array. The output signal of the area sensor 101 is input to the arithmetic and control unit 102. The arithmetic and control unit 102 uses the output of the area sensor 101 to perform calculations such as exposure calculation and TTL dimming calculation.

  FIG. 3 is a diagram for explaining exposure calculation blocking. In the area sensor 101, the arithmetic control device 102 combines adjacent a × a pixels 40 into one exposure calculation block 41, and synthesizes and adds the output signals for each pixel 40 included in the exposure calculation block 41. . As shown in FIG. 3, the exposure calculation block 41 has a square shape, and the number of pixels (a) in the horizontal direction and the vertical direction included in the exposure calculation block 41 is the same.

  During the TTL dimming operation, an operation of reading a signal from the area sensor 101 for each predetermined number of horizontal pixel columns (horizontal lines), so-called thinning-out reading, is performed. FIG. 4A is a diagram for explaining this thinning readout. In FIG. 4A, a pixel 40 with a hatched line indicates a pixel from which an output signal is not read, and a pixel 40 without a hatched line indicates a pixel from which an output signal is read. In FIG. 4, for convenience of illustration, a part of the area sensor 101 is extracted and illustrated. As shown in FIG. 4A, signals are read from the area sensor 101 by d columns for every c columns. The present embodiment is configured such that the readout time can be shortened by performing thinning readout in this way.

  FIG. 4B is a diagram for explaining blocking for TTL dimming calculation. In the area where the area sensor 101 is thinned and read out, the arithmetic and control unit 102 collects adjacent d × e pixels 40 into one TTL dimming calculation block 44 and is included in the TTL dimming calculation block 44. The output signals for each pixel 40 are synthesized and added. The number of pixels in the vertical direction of the TTL dimming calculation block 44 is d corresponding to the d columns to be thinned and read out. In the present embodiment, the TTL dimming calculation block 44 has a horizontally long rectangular shape, and the number of pixels in the horizontal direction is larger than the number of pixels in the vertical direction of the TTL dimming calculation block 44 (that is, d <e). .

  As described above, in this embodiment, the image data of a predetermined number of pixels output from the area sensor 101 is divided into blocks having a size suitable for exposure calculation. Thus, by combining and adding the output signals from the plurality of pixels 40 included in the exposure calculation block 41, the influence of the random noise component can be reduced, and the accuracy of the exposure calculation can be improved. Further, by combining and adding the output signals from the plurality of pixels 40 included in the exposure calculation block 41 to increase the bit width indicating the signal level for each exposure calculation block 41, data having a large bit width in the exposure calculation And the accuracy of exposure calculation can be improved.

(Description of photographing using the flash device 103)
FIG. 5 is a flowchart of a photographing process using the flash device 103. The arithmetic and control unit 102 starts executing the processing shown in FIG. 5 after the camera 1 is turned on. First, in step S <b> 201, the arithmetic and control unit 102 measures the steady light using the area sensor 101. At this time, the area sensor 101 is blocked by the exposure calculation block 41 described above.

  In step S <b> 201, the arithmetic control device 102 accumulates the area sensor 101 under the condition that the output of each exposure calculation block 41 is not saturated. For example, in the first metering of steady light after power-on, the area sensor 101 is accumulated with a predetermined sensitivity and accumulation time. If the output of any of the exposure calculation blocks 41 is saturated, the process returns to step S201 again, and the area sensor 101 is accumulated with lower sensitivity or shorter accumulation time. By repeating this, the area sensor 101 can be accumulated under the condition that the output of each exposure calculation block 41 is not saturated. In the following description, metering of stationary light in step S201 is referred to as first photometry.

  In step S202, the arithmetic and control unit 102 performs a saturation prediction calculation at the time of preliminary light emission. This is an operation for predicting whether or not the output of any pixel of the area sensor 101 is saturated only by steady light in the preliminary light emission of the flash device 103. If the following expression (1) is satisfied, the arithmetic and control unit 102 determines that the area sensor 101 is saturated during preliminary light emission.

  Here, Ymax is the maximum value among the outputs of the total exposure calculation block 41 of the area sensor 101, TVs is the accumulation time of the area sensor 101 in the first photometry, and SVs is the gain (light reception) of the area sensor 101 in the first photometry. Sensitivity). TVs has a time of, for example, about 6 microseconds to 70 milliseconds, depending on the brightness of steady light. TVp is the accumulation time of the area sensor 101 during preliminary light emission, which will be described later, and SVp is the gain of the area sensor 101 during preliminary light emission, which will be described later. Yth on the right side of the above formula (1) is a threshold value that the area sensor 101 considers saturated.

  The left side of the above formula (1) changes the photometric condition (accumulation time and gain) from the photometric result of the first photometry (luminance of stationary light, that is, the maximum value of the output of the exposure calculation block 41) to that at the time of preliminary light emission. The sensor output by the stationary light when it is made to be estimated. If the accumulation time TVp and the gain SVp at the time of preliminary light emission are equal to the accumulation time TVs and the gain SVs at the time of the first photometry, the left side of the above equation (1) becomes Ymax itself, and if the accumulation time and the gain become large, the above equation The left side of (1) has a large value accordingly.

  For example, when shooting is performed using the flash device 103 in the daytime, the storage time TVp at the time of preliminary light emission may be longer than the storage time TVs at the time of the first photometry when the steady light is somewhat large. This is because the accumulation time TVp at the time of preliminary light emission is almost determined by the characteristics of the flash device 103 and cannot be freely changed as in the first photometry. In such a case, in the preliminary light emission of the flash device 103, the output of any pixel included in the area sensor 101 may be saturated only by the steady light. Even if the storage time TVp during the preliminary light emission is not longer than the storage time TVs during the first photometry, for example, if the gain SVp during the preliminary light emission is greater than or equal to the gain SVs during the first light measurement, the flash device In the preliminary light emission 103, the output of any pixel included in the area sensor 101 may be saturated only by steady light. The saturation prediction in step S202 is for coping with such a situation.

  In this embodiment, each exposure calculation block 41 of the area sensor 101 outputs a value from 0 to 1023 according to the amount of incident light. That is, Yth in the above formula (1) can be set to 1023, for example. However, in practice, it is desirable that Yth be a value somewhat lower than 1023 (for example, about 800 to 900). This is because if it is a value close to 1023 with only steady light, it is almost certainly saturated by the reflected light from the subject during preliminary light emission, and the incident light corresponding to one of RGB colors is saturated. Because there is a possibility that.

  In step S203, the arithmetic and control unit 102 determines whether or not a release switch (not shown) has been fully pressed. If it is not fully pressed, the process proceeds to step S211. On the other hand, if the release switch is fully pressed, the process proceeds to step S204.

  In step S204, the arithmetic and control unit 102 starts accumulation of the area sensor 101 for preliminary light emission (the thinning readout operation described above). At this time, the accumulation time TVp of the area sensor 101 is set to a time longer than the light emission time of the flash device 103 (for example, about several hundred microseconds), and includes the time from the start of light emission of the flash device 103 to the completion of light emission. . In addition, the gain SVp of the area sensor 101 is determined based on the result of the saturation prediction calculation in step S202. In step S202, when the above equation (1) is not satisfied, that is, when it is determined by the arithmetic control device 102 that the area sensor 101 is not saturated during preliminary light emission, the arithmetic control device 102 sets the gain SVp of the area sensor 101 to a predetermined value. Is set to an initial value (for example, 8 corresponding to ISO 1600). On the other hand, if it is determined that the area sensor 101 is saturated at the time of preliminary light emission, the gain SVp of the area sensor 101 is a value that does not satisfy the above formula (1) in step S204 (for example, a value equivalent to ISO 100). Set to. The arithmetic and control unit 102 starts accumulation of the area sensor 101 with the accumulation time TVp and the gain SVp determined in this way.

  In step S205, the arithmetic and control unit 102 causes the flash unit 103 to perform preliminary light emission. In step S206, the arithmetic and control unit 102 waits for the accumulation time TVp determined in step S204 to elapse, and then completes accumulation by the area sensor 101. In the following description, the photometry of the reflected light from the subject associated with the preliminary light emission performed from step S204 to step S206 is referred to as second photometry.

  In step S207, the arithmetic and control unit 102 starts accumulation of the area sensor 101 with the same settings as in step S205. In step S208, the arithmetic and control unit 102 waits for the accumulation time TVp determined in step S204 to elapse, and then completes accumulation by the area sensor 101.

  In the following description, the output of each TTL dimming calculation block 44 shown in FIG. 4B during preliminary light emission (steps S204 to S206) is represented as Yp (i, j). Here, i is the column number of the TTL dimming calculation block 44, which is 0, 1, 2,... In order from the left end of FIG. Further, j is a row number of the TTL dimming calculation block 44, which is 0, 1, 2,... In order from the upper end of FIG. Further, the output of each TTL dimming calculation block 44 shown in FIG. 4B at the time of constant light metering after the preliminary light emission (steps S207 to S208) is represented as Ys (i, j). i and j are the same as Yp (i, j).

In step S209, the arithmetic and control unit 102 calculates the light emission amount at the time of photographing. The arithmetic and control unit 102 first calculates the maximum value MYmax of the amount of reflected light from the subject by preliminary light emission from the following equation (2).
MYmax = max {Yp (i, j) −Ys (i, j)} (2)

  That is, the maximum amount of light reflected from the subject by preliminary light emission detected by the TTL dimming calculation block 44 is MYmax. Next, the arithmetic and control unit 102 calculates the light emission amount GN at the time of photographing by the following equation (3).

  Here, GNp is a guide number of the light emission amount of the flash device 103 at the time of preliminary light emission. CONST is a fixed value for correcting the light emission amount. In step S210, the arithmetic and control unit 102 causes the flash unit 103 to flash by the light emission amount GN determined in step S209, and shoots a subject image. In step S211, the arithmetic and control unit 102 determines whether or not a power off button (not shown) of the camera 1 is pressed, that is, whether or not the camera 1 is powered off. If the power is not turned off, the process returns to step S201, and the above processing is repeatedly executed. On the other hand, when the power is turned off, the process is terminated.

According to the camera according to the first embodiment described above, the following operational effects can be obtained.
(1) The area sensor 101 includes a plurality of light receiving elements, and first light measurement that measures steady light by accumulating charges for the accumulation time TVs prior to preliminary light emission, and reflection from a subject associated with the preliminary light emission. Second light metering is performed in which light is metered by accumulating charges for the accumulation time TVp. The arithmetic and control unit 102 predicts whether or not the charge accumulation amount due to the steady light of the area sensor 101 is larger than a predetermined amount in the second photometry from the photometry result of the first photometry, and when the charge accumulation amount becomes larger than the predetermined amount. When the prediction is made, the gain of the area sensor 101 in the second photometry is set to a gain at which the charge accumulation amount due to the steady light becomes a predetermined amount or less. Then, the light emission amount of the flash device 103 at the time of photographing is calculated from the photometry result of the second photometry. Since this is done, it is possible to accurately measure the amount of light reflected from the subject during preliminary light emission.

(2) The photometry result of the first photometry includes the luminance information of the steady light. Further, the accumulation time TVp at the time of the second photometry is determined in advance before the preliminary light emission according to the light emission time of the flash device 103 in the preliminary light emission. The arithmetic and control unit 102 determines the stationary light of the area sensor 101 in the second photometry from the luminance information of the stationary light included in the photometric result of the first photometry, the accumulation time TVs of the first photometry, and the accumulation time TVp of the second photometry. It is predicted whether or not the amount of charge accumulated due to is larger than a predetermined amount. Since this is done, it is possible to accurately measure the amount of light reflected from the subject during preliminary light emission.

(Second Embodiment)
The camera according to the second embodiment has the same configuration as that of the camera 1 according to the first embodiment, except that the accumulation time cannot be uniformly set for each of the plurality of light receiving elements of the area sensor 101. This is different from the first embodiment. Hereinafter, differences from the first embodiment will be described. In the following description, the same portions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 6 is a diagram showing a charge accumulation pattern by the area sensor 101. In FIG. 6A and FIG. 6B, the charge accumulation state of each row of the area sensor 101 is represented by an arrow drawn from left to right, and the horizontal axis indicates the passage of time. In the description of FIG. 6, it is assumed that the number of rows to be subjected to thinning readout at the time of TTL dimming operation is 5, and the row numbers are expressed as j = 0-4.

  The area sensor 101 according to the first embodiment operates with the charge accumulation pattern shown in FIG. When accumulation is started at time T10, charge accumulation is started every predetermined time in order from the row of j = 0. Then, when a predetermined time elapses for each row, the charge accumulation is finished. For example, in a row where j = 0, charge accumulation starts at time T10 and charge accumulation ends at time T12. In the last row, j = 4, charge accumulation starts at time T11, and charge accumulation ends at time T13. Since the preliminary light emission (from the start of light emission to the completion of light emission) of the flash device 103 is executed from time T11 to time T12, each row of the area sensor 101 reliably receives the reflected light from the subject due to the preliminary light emission. can do. Further, since the total accumulation time of each row is constant, the influence of stationary light during photometry is constant for every row.

  On the other hand, the area sensor 101 according to the present embodiment operates with the charge accumulation pattern shown in FIG. Although accumulation of all rows is started at time T20, charge accumulation is finished in order for each row. For example, at time T21, the charge accumulation is completed for the row with j = 0, and then the charge accumulation is completed for the row with j = 1 after a predetermined time, and with the row with j = 2 after a predetermined time. At time T <b> 22, the j = 4 row finishes the charge accumulation, and the charge accumulation of the entire area sensor 101 is finished.

  By configuring the area sensor 101 as shown in FIG. 6B, the entire photometric time can be shortened. That is, the total photometric time (time from time T20 to time T22) in FIG. 6B is shorter than the total photometric time in FIG. 6A (time from time T10 to time T13). ing. On the other hand, the charge accumulation time (TVp) of each row is different for each row.

  The calculation control device 102 according to the present embodiment uses the charge accumulation time TVp at the time of preliminary light emission as the accumulation time among the rows of the area sensor 101 in the saturation prediction calculation using the equation (1) described in the first embodiment. Is the accumulation time of the longest row. That is, in FIG. 6B, the accumulation time (time from time T20 to time T22) of row j = 4 is defined as accumulation time TVp in equation (1). Further, preliminary light emission (from light emission start to light emission completion) by the flash device 103 is executed between time T20 and time T21.

According to the camera of the second embodiment described above, the following operational effects can be obtained.
(1) The plurality of light receiving elements included in the area sensor 101 have different accumulation times. The arithmetic and control unit 102 uses the accumulation time of the pixel having the longest accumulation time among the plurality of light receiving elements of the area sensor 101 as a reference, and the charge accumulation amount by the steady light of the area sensor 101 in the second photometry is greater than a predetermined amount. Predict whether it will grow. Since it did in this way, even if it is a case where the accumulation conditions of area sensor 101 differ for every pixel, control of flash device 103 with high accuracy is attained.

(Third embodiment)
The camera according to the third embodiment has the same configuration as the camera 1 according to the first embodiment, but the method for determining the light emission amount of the flash device 103 at the time of shooting is the same as that of the first embodiment. Is different. Hereinafter, differences from the first embodiment will be described. In the following description, the same portions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The arithmetic and control unit 102 of the present embodiment uses a first calculation mode for calculating the amount of light emitted from the flash unit 103 at the time of shooting using the photometric result of the entire shooting range, and a photometric result of a part of the range provided in the shooting range. And a second calculation mode for calculating the amount of light emitted from the flash device 103 during shooting. Hereinafter, processing contents of the arithmetic control device 102 in the second arithmetic mode will be described. In the case of the first calculation mode, the calculation control device 102 determines the light emission amount at the time of shooting by the same method as in the first embodiment, and thus the description thereof is omitted.

  FIG. 7 is a diagram showing a shooting range and a range for determining the light emission amount of the flash device 103 at the time of shooting in the second calculation mode. In the second shooting mode, the arithmetic and control unit 102 according to the present embodiment sets the light emission amount of the flash device 103 at the time of shooting to a partial range 51 provided near the center of the shooting range 50 instead of the entire shooting range 50. To be determined based on the photometric result at. By determining the light emission amount in this manner, for example, a main subject exists near the center of the shooting range 50, and a bright object such as a streetlight or the sun is present around the shooting range 50 (outside the partial range 51). When it exists, the exposure can be adjusted according to the main subject.

  In the present embodiment, since the light emission amount at the time of shooting is determined by the method described above, the saturation prediction calculation performed in step S202 of FIG. 5 is not based on the entire shooting range 50 but based on a partial range 51. Done. That is, the arithmetic control device 102 according to the present embodiment calculates the amount of charge accumulation due to stationary light in the partial range 51 in the second photometry from the photometry result in the partial range 51 in the first photometry in the second calculation mode. It is predicted whether or not it becomes larger than the fixed amount Yth. Therefore, even when a very bright object or the like exists outside the partial range 51, and the light receiving element corresponding to the position of the object is saturated, the arithmetic and control unit 102 ignores this and predicts saturation. Perform the operation.

According to the camera of the third embodiment described above, the following operational effects can be obtained.
(1) The arithmetic and control unit 102 uses a light receiving element included in the entire photographing range 50 among a plurality of light receiving elements of the area sensor 101 to calculate a light emission amount of the flash device 103 during photographing. The second calculation mode for calculating the light emission amount of the flash device 103 at the time of shooting using only the light receiving elements included in the partial range 51 smaller than the shooting range 50 among the plurality of light receiving elements of the area sensor 101. In the second calculation mode, the arithmetic and control unit 102 determines from the photometric result in the second range of the first photometry whether or not the charge accumulation amount due to stationary light in the partial range 51 becomes larger than a predetermined amount in the second photometry. Predict. Since it did in this way, it becomes possible to ensure the precision of light emission amount calculation, without being influenced by the stationary light of the area | region unrelated to the determination of light emission amount.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(Modification 1)
The present invention can also be applied to an imaging apparatus other than the single-lens reflex camera shown in the above-described embodiments. For example, the present invention can also be applied to a lens-integrated camera, a lens-interchangeable camera that does not have the quick return mirror 111, and the like.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Camera, 100 ... Camera body, 101 ... Area sensor, 102 ... Arithmetic control device, 103 ... Flash device, 111 ... Quick return mirror, 112 ... Focusing screen, 113 ... Pentaprism, 114 ... Eyepiece, 115 ... Mechanical shutter 116: Image sensor, 200: Interchangeable lens, 201: Imaging optical system, 202: Aperture

Claims (5)

A camera capable of controlling a flash device that emits flash light,
A controller that performs preliminary light emission for causing the flash device to emit light prior to photographing;
Prior to the preliminary emission, the first photometry that measures the steady light by accumulating the charge for the first accumulation time and the reflected light from the subject associated with the preliminary emission for the second accumulation time. An optical sensor unit having a plurality of light receiving elements for performing the second photometry by photometry,
A prediction unit that predicts whether or not a charge accumulation amount due to stationary light of the optical sensor unit in the second photometry is greater than a predetermined amount from the photometry result of the first photometry;
When the prediction unit predicts that the charge accumulation amount is larger than the predetermined amount, the light reception sensitivity of the photosensor unit in the second photometry is changed to the light reception sensitivity where the charge accumulation amount due to steady light is equal to or less than the predetermined amount. Sensitivity setting section to be set,
A calculation unit for calculating a light emission amount of the flash device at the time of photographing from a photometric result of the second photometry;
A camera comprising: The camera of claim 1,
The metering result of the first metering includes luminance information of stationary light,
The second accumulation time is determined in advance before the preliminary light emission according to the light emission time of the flash device in the preliminary light emission,
The prediction unit uses the steady light of the optical sensor unit in the second photometry from the luminance information of the steady light included in the photometry result of the first photometry, the first accumulation time, and the second accumulation time. A camera that predicts whether or not the amount of charge accumulated by the sensor becomes larger than a predetermined amount. The camera according to claim 1 or 2,
The plurality of light receiving elements of the optical sensor unit are different in accumulation time,
The predicting unit is configured to determine a charge accumulation amount due to stationary light of the photosensor unit in the second photometry based on an accumulation time of a pixel having the longest accumulation time among the plurality of light receiving elements included in the photosensor unit. A camera that predicts whether or not a predetermined amount is exceeded. The camera according to any one of claims 1 to 3,
The calculation unit calculates a light emission amount of the flash device at the time of photographing using only the light receiving elements included in the first range among the plurality of light receiving elements of the optical sensor unit, and the light A second calculation mode for calculating a light emission amount of the flash device at the time of photographing using only a light receiving element included in a second range smaller than the first range among the plurality of light receiving elements of the sensor unit;
When the calculation unit is in the second calculation mode, the prediction unit calculates a charge accumulation amount due to stationary light in the second range during the second photometry from the photometry result in the second range of the first photometry. A camera characterized by predicting whether or not it will be larger than a fixed amount. In the camera according to any one of claims 1 to 4,
The camera according to claim 2, wherein the second accumulation time is equal to or longer than the first accumulation time.