Image capturing apparatus, control method, and storage medium

Abstract

To provide an imaging apparatus or the like capable of reducing variations in imaging luminance during stroboscopic imaging.SOLUTION: The imaging device includes a measuring unit that measures a light emission amount of the light emitting device, a setting unit (S208) that sets a light emission amount upper limit value that is an upper limit value of the light emission amount, a calculating unit (S207) that calculates a main light emission amount at the time of imaging on the basis of brightness information measured by the measuring unit at the time of pre-light emission, and a determining unit that determines whether or not to continue imaging according to an imaging mode when the calculated main light emission amount is equal to or larger than the set light emission amount upper limit value (S210Yes). And a control unit configured to correct a differential value between the main light emission amount and the light emission amount upper limit value with the imaging parameter, perform imaging using the light emission amount upper limit value as the main light emission amount (S211 to S214), and continue the imaging corrected with the imaging parameter when the determination unit determines to continue the imaging (S216Yes).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an imaging device, a control method, and a program. [Background technology]

[0002] A commonly known method for controlling the amount of light emitted during light-emitting imaging involves performing a pre-flash before the image capture and calculating an appropriate amount of light based on the luminance reflected from the subject, and then performing the image capture using the pre-flash. Patent Document 1 discloses a technique in which the amount of light emitted calculated from the pre-flash result is compared with a predetermined amount of light, and if the amount of light emitted from the pre-flash result is greater, the predetermined amount of light is emitted and the difference is corrected using imaging sensitivity to perform the image capture using the pre-flash. Patent Document 2 also discloses a technique in which, when a "continuous imaging priority mode" is set, imaging sensitivity is increased during imaging compared to when the continuous imaging priority mode is not set. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4547465 [Patent Document 2] Japanese Patent Publication No. 2020-3567 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional technology disclosed in Patent Document 1 has a problem in that the brightness of captured images varies depending on whether or not the image sensitivity is corrected during continuous image capture. Furthermore, the conventional technology disclosed in Patent Document 2 increases the image sensitivity when the "continuous image capture priority mode" is set. Therefore, although it is possible to constantly reduce the amount of light emitted and capture images with the correct exposure value, there is a problem in that noise is more likely to appear in the images.

[0005] An object of the present invention is to provide an imaging device, a control method, and a program that reduce variations in imaging brightness during strobe imaging. [Means for solving the problem]

[0006] In order to achieve the above object, one aspect of the present invention is an imaging device that has a light emitting device attached and that captures an image by emitting light from the light emitting device, the imaging device comprising: a measurement unit that measures the amount of light emitted by the light emitting device; a setting unit that sets an upper limit of the amount of light emitted, which is an upper limit of the amount of light emitted; a calculation unit that calculates the amount of main light emitted during imaging based on luminance information measured by the measurement unit during pre-flash; a determination unit that determines whether to continue imaging depending on the imaging mode; and a control unit that, if the amount of main light emitted calculated by the calculation unit for the amount of main light emitted is equal to or greater than the upper limit of the amount of light emitted set by the setting unit, corrects the difference between the amount of main light emitted and the upper limit of the amount of light emitted using imaging parameters, and captures an image with the upper limit of the amount of light emitted as the amount of main light emitted, and if the determination unit determines that imaging should be continued, continues imaging corrected with the imaging parameters. [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain the effect that the imaging sensitivity is increased during continuous strobe imaging, and by continuing imaging, it is possible to reduce variations in imaging brightness during strobe imaging. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of the configuration of an imaging system according to the present invention; [Figure 2] 4 is a flowchart illustrating an imaging process of the imaging device according to the embodiment of the present invention. [Figure 3] 10 is a flowchart illustrating a process for continuing an exposure control value in the imaging device according to the embodiment of the present invention. [Figure 4] 10 is a flowchart showing processing of a tuning speed according to a second embodiment of the present invention. [Figure 5] 10 is a flowchart showing processing of an upper limit value of light emission amount according to the second embodiment of the present invention. [Figure 6] FIG. 10 is an explanatory diagram of a display example of exposure control values ​​of a camera. [Figure 7] 10A and 10B are explanatory diagrams illustrating an example of detecting a main subject area in image data. [Figure 8] 10A and 10B are diagrams illustrating an example of the relationship between the amount of main flash light emitted by the strobe and the exposure value. [Figure 9] FIG. 10 is an explanatory diagram of an example of a tuning speed. [Figure 10] 10 is an explanatory diagram for limiting the amount of strobe light emitted and shortening the synchronization speed. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the configurations described in the following embodiments are merely examples, and the scope of the present invention is not limited to the configurations described in the embodiments. The camera body 100 shown below corresponds to an imaging device. As will be described later, the "synchronization speed" refers to the fastest shutter speed at which the shutter can remain fully open while the strobe device is firing, and the shutter speed is usually set to approximately 1 / 125 to 1 / 250 (s), which is equal to or lower than the fastest shutter speed available at the synchronization speed. "Synchronization speed priority" refers to such a setting being performed automatically and preferentially through a predetermined operation, and the corresponding mode (imaging mode) is called the "synchronization speed priority mode."

[0010] (Figure 1: Example of imaging system configuration) (camera body 100; lens 200; strobe device 300; mount contact group 103; strobe contact group 109) Fig. 1 is a block diagram showing an example configuration of an imaging system. The imaging system shown in Fig. 1 includes a camera body 100, a lens unit 200, and a strobe device 300. The lens unit 200 is attached to the front of the camera body 100. The lens unit 200 is replaceable, and the camera body 100 and the lens unit 200 are electrically connected via a mount contact group 103. The strobe device 300 is attached to the top surface of the camera body 100. The strobe device 300 is replaceable, and the camera body 100 and the strobe device 300 are electrically connected via a strobe contact group 109.

[0011] (camera body 100) The camera body 100 has a camera control unit 101. Connected to the camera control unit 101 are a shutter 104, an image sensor 102, a camera operation unit 105, a camera display unit 106, and an image storage unit 107. These are connected to the camera control unit 101 so that required information can be communicated, and the camera control unit 101 controls these connected devices. For example, the camera control unit 101 is configured with a microcomputer that controls the operation of each unit of the camera body 100. More specifically, the camera body 100 is configured with a CPU, ROM, RAM, etc., and the required functions of this embodiment are realized by the CPU loading a program stored in the ROM into the RAM and executing it.

[0012] (Image sensor 102: Shutter 104: "First curtain" "Second curtain") The image sensor 102 converts light incident from a subject via the imaging lens 202 into an electrical signal to generate image data and output it to the camera control unit 101. The shutter 104 is a focal plane shutter and is composed of a first curtain and a second curtain. More specifically, the first curtain of the shutter 104 travels and opens, thereby starting exposure of the image sensor 102, and the second curtain of the shutter 104 travels and closes, thereby ending exposure of the image sensor 102. The first and second curtains of the shutter 104 may be configured as light-blocking members that open and block light from the image sensor 102, or at least one of the first and second curtains may be configured as a so-called electronic shutter. In other words, the resetting and readout of accumulated charges in the horizontal direction of the image sensor 102 may be configured to be controlled sequentially from the top (or bottom) line.

[0013] (Camera operation unit 105: Camera display unit 106: Image storage unit 107: SW1 signal: SW2 signal) The camera operation unit 105 includes various operation members for user operation. The camera operation unit 105 is configured with, for example, buttons, switches, dials, connected devices, etc., provided on the camera body 100. The camera operation unit 105 detects operation instructions issued by the user and sends a signal corresponding to the detected operation instruction to the camera control unit 101. The camera operation unit 105 will be described using a release button as an example of the camera operation unit 105. For example, the camera control unit 105 outputs to the camera control unit 101 an instruction signal (hereinafter referred to as an "SW1 signal") issued when the user half-presses the release button and an instruction signal (hereinafter referred to as an "SW2 signal") issued when the user fully presses the release button. The camera display unit 106 displays imaging information, captured images, etc., in response to operation instructions from the camera control unit 101. The image storage unit 107 stores acquired imaging data, and the camera control unit 101 controls writing of captured imaging data to the image storage unit 107.

[0014] (Camera control unit 101: exposure control values ​​(shutter speed, aperture value, ISO sensitivity)) The camera control unit 101 controls the operation of the camera body 100 based on the output signal of the camera operation unit 105. When the output signal of the camera operation unit 105 is an "SW1 signal," the camera control unit 101 drives the image sensor 102 to capture an image and repeats photometry control to measure the brightness of the subject from the captured image. At the same time, the camera control unit 101 determines the shutter speed, aperture value, and ISO sensitivity to be used when capturing an image from the photometry result. Here, the shutter speed, aperture value, and ISO sensitivity to be used when capturing an image are collectively referred to as "exposure control values." The camera control unit 101 displays the determined "exposure control values" on the screen of the camera display unit 106.

[0015] When the output signal of the camera operation unit 105 is an "SW2 signal," the camera control unit 101 drives the aperture 203 in the imaging lens 202, sets the sensitivity (ISO sensitivity) of the imaging element 102, and controls the shutter 104 to irradiate light onto the imaging element 102. The camera control unit 101 displays the captured image on the screen of the camera display unit 106 according to the image data acquired from the imaging element 102, and also controls the writing of the image data into the image storage unit 107.

[0016] (Lens part 200) Next, the configuration of the lens unit 200 will be described. The lens unit 200 includes a lens control unit 201, an imaging lens 202, and an aperture 203. The lens control unit 201 is implemented by a microcomputer that controls the operation of each unit of the lens unit 200. The imaging lens 202 is made up of multiple lenses and forms an image of a subject on the image sensor 102. The imaging lens 202 also includes an aperture 203 for adjusting the amount of light and a focus lens (not shown) for adjusting the focus. The lens control unit 201 adjusts the amount of light taken into the camera body 100 and the focus in accordance with instructions from the camera control unit 101, under control via the mount contact group 103. The lens control unit 201 is configured to include, for example, a CPU, ROM, RAM, etc., and is configured to be able to adjust the amount of light taken into the camera body 100, the focus, etc., by the CPU loading a program stored in the ROM into the RAM and executing it.

[0017] (Strobe device 300: strobe control unit 301) Next, the configuration of the strobe device 300 will be described. The strobe device 300 includes a strobe control unit 301, a light emission unit 302, a strobe operation unit 303, a strobe display unit 304, a light pulse receiving unit 305, and a strobe contact group 109. The strobe control unit 301 is a microcomputer that controls the operation of each unit of the strobe device 300. The strobe control unit 301 can communicate required information with the camera control unit 101 via the strobe contact group 109, and receives light emission control instructions and camera information from the camera body 100, transmits strobe information, etc. In other words, the strobe control unit 301 is composed of, for example, a CPU, ROM, RAM, etc., and receives light emission control instructions and camera information from the camera body 100, transmits strobe information, etc., by the CPU expanding a program stored in the ROM into the RAM and executing it.

[0018] (Light emitting unit 302: Strobe operation unit 303: Strobe operation unit 303: Strobe display unit 304) The light emitting unit 302 is realized by a discharge tube, a light emitting capacitor, a light emitting circuit, a light emitting optical system, etc., and emits a flash of light. The light emitting unit 302 emits light by driving the light emitting circuit in response to instructions from the strobe control unit 301 and discharging the energy charged in the light emitting capacitor to the discharge tube, illuminating the subject via the light emitting optical system. The strobe operation unit 303 has an operation unit operated by the user, detects operation instructions given by the user via buttons, dials, etc. attached to the strobe device 300, and transmits a signal corresponding to the operation instruction to the strobe control unit 301. The strobe display unit 304 displays the light emitting mode, etc. in response to instructions from the strobe control unit 301.

[0019] (Light pulse receiving unit 305) The light pulse receiving unit 305 receives light pulses emitted from the light emitting unit 302 of another strobe device and outputs the reception result to the strobe control unit 301. The light emission amount may be set by the strobe operation unit 303, or may be obtained by communication from the camera control unit 101 via the strobe contact group 109. The strobe control unit 301 receives a control signal from the camera control unit 101 via the strobe contact group 109 and causes the light emitting unit 302 to emit a predetermined light emission amount in synchronization with the imaging operation of the camera body 100. As a result, the camera body 100 can measure the light emission amount of the strobe device 300.

[0020] <First embodiment: FIG. 2: Flowchart showing imaging processing) Next, the imaging process of the camera body 100 of this embodiment will be described with reference to the flowchart in Figure 2. Here, we will assume that imaging is performed with the flash of the strobe device 300 "ON" and the "automatic light control mode" selected as the imaging mode in the camera body 100. "Automatic light control mode" is a mode in which a pre-flash is performed before imaging, and the amount of light emitted during imaging is calculated based on data on the light reflected from the subject, thereby achieving imaging with appropriate exposure. Even in "automatic light control mode," the camera body 100 can measure the amount of light emitted by the strobe device 300.

[0021] (Step S201: SW1 signal is ON) First, in step S201, if the SW1 signal is turned on (Yes), the camera control unit 101 proceeds to step S202. Note that if the SW1 signal is not turned on (No), the process goes to a wait state in S201.

[0022] (Step S202: Flash sync speed) Next, in step S202, the camera control unit 101 sets the "flash synchronization speed." At the "synchronization speed" for flash imaging, flash emission is permitted when the front shutter curtain has completed its travel and the entire image is open to the image sensor 102. This refers to the shutter speed at which the shutter is fully open for the shortest period when the rear shutter curtain is caused to travel at a timing that achieves a predetermined amount of maximum flash emission, relative to the value of the maximum flash emission amount obtained from the flash device 300 via the flash contact group 109.

[0023] (Fig. 9: Explanation of flash synchronization speed) In Figure 9, "S1" indicates the travel of the front curtain of the shutter, and "S2" indicates the travel of the rear curtain of the shutter (the same applies to S1 and S2 in Figure 10). In the case of a mechanical shutter system, the image sensor 102 is exposed to light by the travel of the front curtain of the shutter, and is blocked by the rear curtain of the shutter. In the case of an electronic shutter system, the horizontal accumulated charge of the image sensor 102 is reset by front curtain control, and the accumulated charge of each row of the image sensor 102 is read out sequentially by rear curtain control.

[0024] The period shown in Figure 9 (1) represents the control of the first shutter curtain, and is the shutter travel time. The light output curve in the figure shows the change in light output over time when the flash is fired. The maximum light output is represented as "1," and the amount at which the light output is half is represented as "1 / 2." The second curtain begins to travel once the light output has dropped to "1 / 2," so (2) in Figure 9 is the fully open section, and the time "(1) + (2)," or the shutter speed "Tv = 1 / 250 (s)," is the flash synchronization speed.

[0025] (Step S203 (Determine Exposure Control Value): Step S204 (Display Exposure Control Value)) Next, in step S203, the camera control unit 101 executes AF and AE operations. That is, "exposure control values" including shutter speed, aperture value, and ISO sensitivity are determined when the flash device 300 attached to the camera body 100 is not firing. The upper limit of the shutter speed is the synchronization speed (Tv=1 / 250) set in step S202. In this embodiment, it is assumed that the shutter speed (Tv=1 / 250), aperture value (F5.6), and ISO sensitivity (ISO100) are determined as the "exposure control values." Next, in step S204, the camera control unit 101 displays the "exposure control values" determined in step S203 on the camera display unit 106.

[0026] (Fig. 6(a): Example of camera exposure control value display: Step S205 (SW2 signal ON)) 6(a) is a display example of the "exposure control values" in this embodiment, displaying the shutter speed (Tv1 / 250), aperture value (F5.6), and ISO sensitivity (ISO100). Next, in step S205, if the "SW2 signal" is turned ON, the camera control unit 101 proceeds to the process in step S206. If the "SW2 signal" is not turned ON (No), the camera control unit 101 enters a wait state in step S201.

[0027] (Step S206: Pre-flash) Next, in step S206, the camera control unit 101 acquires luminance information of the external light immediately before the pre-flash from the image sensor 102, calculates the luminance in the multiple divided photometric areas, and performs pre-flash control on the strobe device 300. Note that the camera control unit 101 can also detect the subject as a main subject if the luminance information measured during the pre-flash is equal to or greater than a predetermined value, or as a sub-subject if it is less than the predetermined value.

[0028] (Step S207: Calculate the actual light emission amount) Next, in step S207, the camera control unit 101 acquires luminance information from the image sensor 102 at the time of pre-flash in step S206, calculates the luminance in the multiple divided photometric areas, and then calculates the difference in luminance between the external light immediately before the pre-flash and the divided photometric areas of the pre-flash, to estimate the area where the main subject is located at a distance where main flash is effective.

[0029] (Fig. 7: An example of detecting the main subject area in image data) Figure 7 shows examples of "main subject," "split metering frames," and other elements in image data, used to illustrate main subject area estimation. In such images, a "main subject area estimation method" is employed, which assumes that the main subject is located at a position within each split metering frame where the reflected light from the pre-flash is greater than a certain threshold. Note that Figure 7 shows an example in which 12 split metering frames are arranged vertically and 16 split metering frames are arranged horizontally.

[0030] Here, the "sub-subject (background, etc.) area" and the "main subject area" may be separated into "0" and "1," and a certain threshold value may be given as an absolute value of the brightness level or as a value relative to the area estimated to be the background. According to the "main subject area estimation method" described above, in the image data shown in FIG. 7(A), the gray frame in FIG. 7(b) is estimated as main subject area "1." For this main subject area "1," the amount of main flash is calculated from the "subject brightness of external light just before pre-flash and subject brightness at the time of pre-flash (subject brightness at pre-flash - subject brightness of external light just before pre-flash)," and the target brightness.

[0031] (Step S208 (light emission amount upper limit value processing): Step S209 (exposure control value correction continuation determination)) Next, in step S208, the camera control unit 101 acquires the maximum light emission amount from the strobe device 300 via the strobe contact group 109 and sets it as the upper limit of the light emission amount (upper light emission amount value). In this embodiment, the maximum light emission amount is full emission, or "1 / 1 emission." Next, in step S209, the camera control unit 101 determines whether the flag for continuing exposure control value correction is "1." If the camera control unit 101 determines that the flag for continuing exposure control value correction is "1" (Yes), the process proceeds to step S214. On the other hand, if the camera control unit 101 determines that the flag for continuing exposure control value correction is not "1" (No), the process proceeds to step S210. The initial value of the flag for continuing exposure control value correction is "0."

[0032] (Step S210: Step S211 (Setting the main light emission amount to the upper limit of the light emission amount)) Next, in step S210, the camera control unit 101 compares the amount of main flash obtained in the calculation of the amount of main flash in step S207 with the upper limit of flash amount set in step S208. If the amount of main flash is equal to or greater than the upper limit of flash amount (1 / 1 of full flash) (Yes), the camera control unit 101 proceeds to step S211. On the other hand, if the amount of main flash is not equal to or greater than the upper limit of flash amount (No), the camera control unit 101 proceeds to step S214. In other words, if the upper limit of flash amount is greater than the amount of main flash, the camera control unit 101 proceeds to step S214. Next, in step S211, the camera control unit 101 updates the amount of main flash obtained in the calculation of the amount of main flash in step S207 to the upper limit of flash amount (1 / 1 of full flash) set in step S208.

[0033] (Step S212 (updating exposure control value)) Next, in step S212, the camera control unit 101 corrects the ISO sensitivity at the time of image capture based on the difference between the main flash amount calculated in step S207 and the upper limit value of the flash light amount set in step S208, and proceeds to step S213. Note that the correction of the ISO sensitivity is merely an example of correcting the difference value with an exposure control value (image capture parameter).

[0034] (Fig. 8: An example of the relationship between the flash output and exposure value) Here, we will explain the specific method of ISO sensitivity correction. Figure 8 is a graph showing the relationship between the amount of main flash emitted by the strobe and the exposure value. The horizontal axis represents the "main flash amount" of the strobe, and the vertical axis represents the "exposure value (EV)" at the time of the main flash. If the amount of main flash calculated in step S207 of Figure 8 is four times the "1 / 1 flash" amount, the exposure value is "10 EV," indicating that the main subject can be captured with proper exposure. However, because the upper limit of the flash amount set in step S208 only allows for full flash ("1 / 1 flash"), the exposure value is limited to "8 EV," and the main subject is 2 EV darker than the proper exposure. In other words, the main subject is 2 EV darker than the proper exposure. Therefore, by correcting this "2 EV" exposure difference value toward the higher sensitivity side using ISO sensitivity, it is possible to capture the main subject with proper exposure.

[0035] In this embodiment, in order to capture an image with a proper exposure, the above-mentioned difference value is corrected toward the high sensitivity side with respect to the ISO sensitivity to increase the light sensitivity of the flash. Alternatively, a method may be used in which the aperture value of the exposure control value is corrected toward the open side to increase the amount of light received from the flash, or a method may be used in which both the ISO sensitivity and the aperture value are corrected.

[0036] (Step S213 (Exposure control value display update): FIG. 6(b): Exposure control value correction display example) Next, in step S213, the camera control unit 101 displays on the camera display unit 106 that the exposure control value for ISO sensitivity determined in step S212 has been updated. An example of a display when the exposure control value for ISO sensitivity has been updated will be described below with reference to FIG. 6(b). In step S212, the ISO sensitivity was corrected by a difference value of "2 EV" from the appropriate exposure value, so "ISO correction amount +2" is displayed, as shown in FIG. 6(b), to indicate that the sensitivity has been increased by "2 EV" from the ISO sensitivity of "100" determined in step S203.

[0037] (Step S214 (strobe imaging)) Next, in step S214, the camera control unit 101 controls the image sensor 102, the shutter 104, and the lens control unit 201 using the shutter speed, lens aperture value, and ISO sensitivity determined in step S203 or the ISO sensitivity determined in step S212. Then, the camera control unit 101 notifies the strobe control unit 301 of the main flash amount calculated in step S207 or step S211, and performs flash imaging by synchronizing the strobe emission with the exposure timing of the image sensor 102.

[0038] (Step S215: FIG. 3: Flowchart showing exposure control value correction continuation processing: Step S300) Next, in step S215, the camera control unit 101 executes processing to continue exposure control value correction. Detailed processing will be described with reference to the flowchart in Fig. 3. First, in step S301, the camera control unit 101 determines whether the amount of main flash light calculated in step S207 has been updated to the upper limit of flash light amount set in step S208. If the camera control unit 101 determines that the amount of main flash light has been updated to the upper limit of flash light amount (Yes), it proceeds to step S302. However, if it determines that the amount of main flash light has not been updated to the upper limit of flash light amount (No), it proceeds to step S306.

[0039] (Step S302) Next, in step S302, the camera control unit 101 determines whether the set imaging mode is the exposure control value correction continuation mode (correction continuation mode). The "exposure control value correction continuation mode" can be set by operating the dial, switch, etc., which are the camera operation unit 105, and is a state in which exposure control value correction is continued. If the exposure control value correction continuation mode is "On" (Yes), the camera control unit 101 proceeds to step S303, but if the exposure control value correction continuation mode is not "On" (No), the camera control unit 101 proceeds to step S306. In other words, if the exposure control value correction continuation mode (correction continuation mode), which sets whether or not to continue imaging corrected with imaging parameters, is set (if On), the camera control unit 101 determines to continue imaging.

[0040] (Step S303) Next, in step S303, the camera control unit 101 determines whether or not the camera is in continuous shooting mode. The "continuous shooting mode" can be set by operating the dials, switches, etc., of the camera operation unit 105, and is a state in which image capture is performed continuously. If the camera control unit 101 determines that the camera is in continuous shooting mode (Yes), the process proceeds to step S304, whereas if the camera control unit 101 determines that the camera is not in continuous shooting mode (No), the process proceeds to step S306. In other words, if the continuous shooting mode is set, the camera control unit 101 determines that image capture should be continued.

[0041] (Step S304) Next, in step S304, the camera control unit 101 determines whether or not the main flash intensity calculation in step S207 detected a "main subject area" and a "sub-subject area" and performed main flash intensity calculation. If the result of this determination is that the "main subject area" and "sub-subject area" were detected and main flash intensity calculation was performed as shown in FIG. 7(b), the camera control unit 101 proceeds to step S305. On the other hand, in other cases (No), the camera control unit 101 proceeds to step S306. In other words, if the main subject and sub-subject were detected and main flash intensity calculation was performed in the main flash intensity calculation process in S207, the camera control unit 101 determines to continue image capture.

[0042] (Step S305: Step S306) Then, in step S305, the camera control unit 101 sets the flag for continuing exposure control value correction to "1" and ends the exposure control value correction continuation process. Also, in step S306, the camera control unit 101 sets the flag for continuing exposure control value correction to "0" and ends the exposure control value correction continuation process.

[0043] (Step S216 in Figure 2) 2, in step S216, the camera control unit 101 determines whether to continue exposure control value correction. That is, if the camera control unit 101 determines that the exposure control value correction continuation flag set in step S215 is "1" (Yes), the process returns to step S203 and continues image capture. On the other hand, if the camera control unit 101 determines that the exposure control value correction continuation flag is "0" (No), the process in FIG. 2 ends.

[0044] By controlling in this manner, the imaging sensitivity can be increased during continuous flash imaging, and by continuing to capture images, variations in imaging brightness during flash imaging can be reduced. Furthermore, correcting the difference between the calculated main flash amount and the set upper limit of the flash amount using imaging parameters can be performed in the following ways, for example. For example, the camera control unit 101 either (1) corrects the imaging sensitivity toward a higher sensitivity, (2) corrects the lens aperture value toward a larger aperture, or (3) corrects the imaging sensitivity toward a higher sensitivity and also corrects the lens aperture value toward a larger aperture.

[0045] Second Embodiment Next, a second embodiment will be described. In the second embodiment, the operation of an image capture device in which the camera body 100 further has a "synchronization speed priority mode" will be described. The processing flow of the second embodiment is basically the same as that shown in FIG. 2. However, the synchronization speed setting process in step S202 and the upper limit light emission amount process in step S208 will be described as processes including the "synchronization speed priority mode" with reference to FIGS. 4 and 5.

[0046] (FIG. 4: Synchronization speed setting process according to the second embodiment: Step S401; FIG. 10: An explanatory diagram of a control example in which the amount of strobe light emitted is limited to shorten the synchronization speed) First, the synchronization speed setting process will be described with reference to FIG. 4. First, in step S401, the camera control unit 101 determines whether the "synchronization speed priority mode" is "On." The "synchronization speed priority mode" refers to a synchronization speed that is faster than the synchronization speed shown in FIG. 9 described in the first embodiment. Specifically, as shown in FIG. 10, this can be achieved by limiting the amount of light emitted (by shortening the light emission time) and shortening the fully open section (2)'. In FIG. 10, "Tv=1 / 320 (s)" is shorter than in FIG. 9, and as in FIG. 9, the period indicated by (1) represents the control of the front curtain of the shutter and is the running time. The maximum amount of light emitted is set to "1," and the rear curtain starts running after the light amount has decreased to "1 / 2." In FIG. 10, (2)' is the fully open section.

[0047] In the second embodiment, when the synchronization speed priority mode is not "On", the synchronization speed is "Tv=1 / 250" and the upper limit of the flash output is "1 / 1 flash". On the other hand, when the synchronization speed priority mode is "On", the synchronization speed is "Tv=1 / 320" and the upper limit of the flash output is "1 / 4 flash". As a result of determining whether the synchronization speed priority mode is set, if the synchronization speed priority mode is "On" (Yes), the camera control unit 101 proceeds to step S402, but if the synchronization speed priority mode is not "On" (No), the camera control unit 101 proceeds to step S403.

[0048] (Step S402: Step S403) Next, in step S402, the camera control unit 101 sets the synchronization speed (Tv=1 / 320) when the light emission amount is limited, and ends the synchronization speed setting process. Also, in step S403, the camera control unit 101 sets the synchronization speed (Tv=1 / 250) when the light emission amount is not limited, and ends the synchronization speed setting process. In the next step S203, the exposure control value is determined as in the first embodiment, but with regard to the upper limit of the shutter speed, if the "synchronization speed priority mode" is set to "On" in step S402, the shutter speed can be controlled up to (TV=1 / 320).

[0049] (FIG. 5: Processing of the upper limit of the light emission amount according to the second embodiment) (Step S501) Next, referring to Fig. 5, the light emission amount upper limit value processing according to the second embodiment, which corresponds to step S208 in Fig. 2, will be described. First, in step S501, the camera control unit 101 determines whether the synchronization speed priority mode is "On." If the camera control unit 101 determines that the synchronization speed priority mode is "On" (Yes), the processing proceeds to step S502. However, if the camera control unit 101 determines that the synchronization speed priority mode is not "On" (No), the processing proceeds to step S508.

[0050] (Step S502) Next, in step S502, the camera control unit 101 determines whether the flag for continuing exposure control value correction is "1." If the camera control unit 101 determines that the flag for continuing exposure control value correction is "1" (Yes), the process proceeds to step S503. However, if the camera control unit 101 determines that the flag for continuing exposure control value correction is not "1" (No), the process proceeds to step S504. In the second embodiment, when capturing an image for the first time or when exposure control value correction is not being continued, the upper limit of the light emission amount is set in step S507 or S508, which will be described later.

[0051] (Step S503: Yes) Next, in step S503, the camera control unit 101 determines whether or not an upper limit value for the amount of light emitted when a light emission amount limit is imposed has been set. In step S503, the flag for continuing exposure control value correction is "1," indicating that exposure control value correction is ongoing. Therefore, if the camera control unit 101 determines that an upper limit value for the amount of light emitted when a light emission amount limit is imposed has been set (Yes), the camera control unit 101 ends the upper limit value processing for the amount of light emitted without updating the upper limit value for the amount of light emitted.

[0052] (Step S503: No; Step S505) On the other hand, if the camera control unit 101 determines that the upper limit of the light emission amount when the light emission amount is limited has not been set (No), in other words, if it determines that the upper limit of the light emission amount when the light emission amount is not limited has been set, the camera control unit 101 executes the following process. That is, since there is a possibility that the setting of the upper limit of the light emission amount will be updated, the camera control unit 101 proceeds to step S505. Next, in step S505, the camera control unit 101 determines whether the shutter speed for the current image capture is the synchronization speed when the light emission amount is limited.

[0053] (Step S505: No) In step S505, the upper limit of the light emission amount when no light emission amount limit is applied is set. Therefore, if the shutter speed for the current image capture is not a synchronization speed with a light emission amount limit applied (No), that is, if it is a synchronization speed with no light emission amount limit applied, the upper limit of the light emission amount is not updated and the light emission amount upper limit value processing ends.

[0054] (Step S505: Yes: Step S506) On the other hand, if the shutter speed for the current image capture is the synchronization speed with the flash light amount limit applied, the flash light amount upper limit value "1 / 1 flash" when the flash light amount limit is not applied is switched to "1 / 4 flash" when the flash light amount limit is applied in the next step S507. Therefore, if the ISO sensitivity correction amount used in the previous image capture is continued, the exposure will be underexposed by the amount of the flash light amount being limited from "1 / 1" to "1 / 4." Therefore, the camera control unit 101 proceeds to the next step S506, clears the exposure control value correction continuation flag to "0," and performs the processes of steps S211 and S212 again.

[0055] (Step S504) Next, in step S504, the camera control unit 101 determines whether the shutter speed for this image capture is a synchronization speed with a light emission amount limit. If the camera control unit 101 determines that the synchronization speed is a synchronization speed with a light emission amount limit (Yes), the camera control unit 101 proceeds to step S507. On the other hand, if the camera control unit 101 determines that the synchronization speed is not a synchronization speed with a light emission amount limit (No), in other words, if the camera control unit 101 determines that the synchronization speed is not a synchronization speed with a light emission amount limit, the camera control unit 101 proceeds to step S508.

[0056] (Step S507: Step S508) Then, in step S507, the camera control unit 101 sets the upper limit value for the amount of light emitted when the amount of light emitted is limited, and ends the upper limit value processing. Also, in step S508, the camera control unit 101 sets the upper limit value for the amount of light emitted when the amount of light emitted is not limited, and ends the upper limit value processing.

[0057] By controlling in this way, it is possible to increase the imaging sensitivity during continuous strobe imaging, and by continuing to capture images, it is possible to reduce variations in the image brightness during strobe imaging. In other words, when increasing the strobe speed by limiting the amount of strobe light (light emission time) and shortening the period when the shutter is fully open, the light emission may be about two stops lower than the appropriate dimming because the amount of light emitted is limited and the period when the shutter is fully open is shortened.

[0058] In this case, for example, when the shutter speed Tv fluctuates during continuous shooting, variations in light control occur in the continuous shot images. However, if the result of light control during continuous shooting exceeds the light emission limit value (upper limit), the light emission is set to that light emission limit value, the difference between the appropriate light emission amount and the light emission limit value is corrected using imaging parameters, and the upper limit value of the light emission amount is used as the actual light emission amount for image capture. Correction using imaging parameters can be performed by, for example, adding the difference value to the ISO sensitivity before capturing an image.

[0059] As a result, during flash continuous shooting, after limiting the flash output, the difference between the appropriate flash control value and the flash output limit value is corrected using the ISO sensitivity, making it possible to continue appropriate flash control, and reducing variations in image brightness during continuous flash shooting. While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments and various modifications and variations are possible within the scope of the present invention. For example, although the camera body 100 and the flash device 300 have been described as separate devices in this embodiment, they may also be configured as an integrated unit.

[0060] <Modification> (1) As described above, in step S206, the camera control unit 101 acquires luminance information of the external light immediately before the pre-flash from the image sensor 102 and calculates the luminance in the multiple divided photometric areas, and can execute the following process at this time. That is, the camera control unit 101 can determine that a main subject has been detected if the luminance information measured during the pre-flash is equal to or greater than a predetermined value, and that a sub-subject has been detected if the luminance information is less than the predetermined value. (2) The camera control unit 101 may also be configured to capture an image at a second shutter speed that is faster than the first shutter speed, and continue capturing an image with the corrected imaging parameters if the next image capture is slower than the second shutter speed. The camera control unit 101 may also be configured to enable the processing of Fig. 2 when continuous image capture is set in "drive mode" during driving.

[0061] <Additional Note> The disclosure of this embodiment includes the following configuration, method, and program. (Configuration 1) An imaging device to which a light emitting device is attached and which captures an image by emitting light from the light emitting device, a measurement unit for measuring the amount of light emitted by the light-emitting device; a setting unit that sets an upper limit of the light emission amount; a main light emission amount calculation unit that calculates a main light emission amount at the time of image capture based on luminance information measured by the measurement unit during pre-flash; a determination unit that determines whether or not to continue imaging according to an imaging mode; a control unit that, when the main light emission amount calculated by the main light emission amount calculation unit is equal to or greater than the light emission amount upper limit value set by the setting unit, corrects a difference between the main light emission amount and the light emission amount upper limit value using imaging parameters, and captures images using the light emission amount upper limit value as the main light emission amount, and, when the determination unit determines that imaging should be continued, continues imaging corrected with the imaging parameters. (Configuration 2) The determination unit 2. The imaging device according to configuration 1, wherein when the imaging mode is set to a continuous shooting mode in which a plurality of consecutive images are captured, it is determined that imaging should be continued. (Configuration 3) The determination unit 2. The imaging device according to configuration 1, wherein when the imaging mode is set to a correction continuation mode in which imaging corrected by imaging parameters is continued, it is determined that imaging is to be continued. (Configuration 4) The determination unit 3. The imaging device according to configuration 1 or 2, wherein when the main subject and sub-subject are detected by the main flash amount calculation unit and the main flash amount calculation is performed, it is determined that imaging should be continued. (Configuration 5) The setting unit 3. The imaging device according to configuration 1 or 2, wherein when the synchronization speed is not prioritized, an upper limit value for the amount of light emitted by the light emitting device is set when no limit is imposed on the amount of light emitted. (Configuration 6) The setting unit The imaging device according to configuration 1 or 2, characterized in that when the judgment unit determines not to continue imaging in a state where synchronization speed is prioritized, and when the shutter speed for the current imaging is a synchronization speed with a light emission amount limit applied, an upper limit value for the light emission amount when a light emission amount limit is applied to the light emitting device is set. (Configuration 7) The control unit further The imaging device according to configuration 4, wherein if the luminance information measured by the measurement unit during pre-flash is equal to or greater than a predetermined value, the object is detected as a main subject, and if it is less than the predetermined value, the object is detected as a sub-subject. (Configuration 8) The control unit further 3. The imaging device according to claim 1, wherein an image is captured at a second shutter speed that is faster than the first shutter speed, and if the next image is captured at a speed slower than the second shutter speed, the imaging device continues capturing images using the corrected imaging parameters. (Configuration 9) the imaging parameter is imaging sensitivity or lens aperture value, 3. The imaging device according to configuration 1 or 2, wherein correcting the difference value with the imaging parameters is any one of correcting the imaging sensitivity toward a higher sensitivity side, correcting the lens aperture value toward a wider aperture, and correcting the imaging sensitivity toward a higher sensitivity side and correcting the lens aperture value toward a wider aperture. (Configuration 10) 3. The imaging device according to configuration 1 or 2, further comprising a display unit that displays the difference value. (method) A control method for an imaging device to which a light emitting device is attached and which captures an image by emitting light from the light emitting device, a measuring step of measuring the amount of light emitted by the light-emitting device; a setting step of setting an upper limit value of the light emission amount, which is an upper limit value of the light emission amount; a main light emission amount calculation step of calculating a main light emission amount at the time of image capture based on the luminance information measured in the measurement step during pre-flash; a determination step of determining whether or not to continue imaging according to the imaging mode; a control step of, when the main light emission amount calculated in the main light emission amount calculation step is equal to or greater than the light emission amount upper limit value set in the setting step, correcting a difference between the main light emission amount and the light emission amount upper limit value using imaging parameters and capturing an image with the light emission amount upper limit value as the main light emission amount, and, when it is determined in the determination step that capturing an image should be continued, continuing capturing an image corrected with the imaging parameters. (program) A program that causes a computer to execute a control method for an imaging device that is equipped with a light-emitting device and that emits light to capture an image, The control method includes: a measuring step of measuring the amount of light emitted by the light-emitting device; a setting step of setting an upper limit value of the light emission amount, which is an upper limit value of the light emission amount; a main light emission amount calculation step of calculating a main light emission amount at the time of image capture based on the luminance information measured in the measurement step during pre-flash; a determination step of determining whether or not to continue imaging according to the imaging mode; a control step of correcting a difference between the main light emission amount and the upper limit value of the light emission amount using an imaging parameter when the main light emission amount calculated in the main light emission amount calculation step is equal to or greater than the upper limit value of the light emission amount set in the setting step, and capturing an image with the upper limit value of the light emission amount as the main light emission amount when it is determined in the determination step that capturing an image should be continued, the program comprising:

[0062] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the present invention. For example, the present invention can be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or recording medium, and having a computer processor in the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions. [Explanation of symbols]

[0063] 100 Camera body 101 Camera control unit 102 Image sensor 104 Shutter 105 Camera control unit 106 Camera display 200 Lens section 201 Lens control unit 203 Aperture 300 Strobe Device 301 Strobe control unit 302 Light-emitting part

Claims

1. An imaging device to which a light emitting device is attached and which captures an image by emitting light from the light emitting device, a measurement unit for measuring the amount of light emitted by the light-emitting device; a setting unit that sets an upper limit of the light emission amount; a calculation unit that calculates the amount of main light emission during imaging based on the luminance information measured by the measurement unit during pre-flash; a determination unit that determines whether or not to continue imaging according to an imaging mode; and a control unit that, when the amount of main light emission calculated by the calculation unit is equal to or greater than the upper limit of light emission amount set by the setting unit, corrects a difference between the amount of main light emission and the upper limit of light emission amount using imaging parameters, and captures an image with the upper limit of light emission amount as the amount of main light emission, if the determination unit determines that imaging should be continued, continues imaging corrected with the imaging parameters.

2. The determination unit 2. The imaging device according to claim 1, wherein when the imaging mode is set to a continuous shooting mode in which a plurality of consecutive images are captured, it is determined that imaging should be continued.

3. The determination unit 2. The imaging apparatus according to claim 1, wherein when the imaging mode is set to a correction continuation mode in which imaging corrected by imaging parameters is continued, it is determined that imaging is to be continued.

4. The determination unit 3. The imaging device according to claim 1, wherein when the calculation unit detects a main subject and a sub-subject and calculates the amount of main light emission, it is determined that imaging should be continued.

5. The setting unit 3. The imaging device according to claim 1, wherein, when the synchronization speed is not prioritized, an upper limit value for the amount of light emitted by the light emitting device is set when no limit is imposed on the amount of light emitted.

6. The setting unit 3. The imaging device according to claim 1, wherein when the judgment unit determines that imaging should not be continued in a state where synchronization speed is prioritized, and when the shutter speed for the current imaging is a synchronization speed with a limit on the amount of light emitted, an upper limit on the amount of light emitted by the light-emitting device with a limit on the amount of light emitted is set.

7. The control unit further 5. The imaging device according to claim 4, wherein when the luminance information measured by said measuring section during pre-flash is equal to or greater than a predetermined value, the object is detected as a main subject, and when the luminance information is less than the predetermined value, the object is detected as a sub-subject.

8. The control unit further 3. The imaging device according to claim 1, wherein an image is captured at a second shutter speed that is faster than the first shutter speed, and if the next image is captured at a speed slower than the second shutter speed, the imaging device continues capturing images using the corrected imaging parameters.

9. the imaging parameter is imaging sensitivity or lens aperture value, 3. The imaging device according to claim 1, wherein correcting the difference value with the imaging parameters is any one of correcting the imaging sensitivity toward a higher sensitivity side, correcting the lens aperture value toward a wider aperture, and correcting the imaging sensitivity toward a higher sensitivity side and correcting the lens aperture value toward a wider aperture.

10. 3. The imaging apparatus according to claim 1, further comprising a display unit that displays the difference value.

11. A control method for an imaging device to which a light emitting device is attached and which captures an image by emitting light from the light emitting device, a measuring step of measuring the amount of light emitted by the light-emitting device; a setting step of setting an upper limit value of the light emission amount, which is an upper limit value of the light emission amount; a calculation step of calculating the amount of main light emitted during imaging based on the luminance information measured in the measurement step during pre-flash; a determination step of determining whether or not to continue imaging according to the imaging mode; a control step of, when the actual light emission amount calculated in the calculation step is equal to or greater than the upper light emission amount limit value set in the setting step, correcting a difference between the actual light emission amount and the upper light emission amount limit value using an imaging parameter, and capturing an image with the upper light emission amount limit value as the actual light emission amount, if it is determined in the determination step that capturing an image should be continued, continuing capturing an image corrected with the imaging parameter.

12. A program that causes a computer to execute a control method for an imaging device that is equipped with a light-emitting device and that emits light to capture an image, The control method includes: a measuring step of measuring the amount of light emitted by the light-emitting device; a setting step of setting an upper limit value of the light emission amount, which is an upper limit value of the light emission amount; a calculation step of calculating the amount of main light emitted during imaging based on the luminance information measured in the measurement step during pre-flash; a determination step of determining whether or not to continue imaging according to the imaging mode; a control step of correcting a difference between the main light emission amount and the upper limit light emission amount using imaging parameters when the main light emission amount calculated in the calculation step is equal to or greater than the upper limit light emission amount set in the setting step, and capturing an image with the upper limit light emission amount as the main light emission amount when it is determined in the determination step that capturing an image should be continued, the program comprising:

Images