Image capture control device, image capture control method, and control program

Abstract

The present invention provides an imaging control device that can suppress the occurrence of uneven lighting by setting an appropriate shutter speed. [Solution] The imaging control device 101, which controls the operation of the imaging device 100, determines the upper limit of the configurable shutter speed in the imaging device 100 based on information regarding the flat emission frequency of the light-emitting device 300.

Description

Technical Field

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

Background Art

[0002] Conventionally, there has been a shooting method called high-speed sync shooting in which, at the time of slit exposure when the shutter speed of a camera is faster than the strobe synchronization speed, the strobe emits flat light for exposure. In this case, there has been a problem that uneven brightness of flat light appears in the captured image. To address this problem, for example, Patent Document 1 discloses a technique in which a strobe determines a pulse period for flat light emission based on the shutter speed information of the camera.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since there is an upper limit to the emission pulse period that can be set for the strobe, in the technique disclosed in Patent Document 1, depending on the shutter speed of the camera, uneven brightness appears in the captured image.

[0005] In view of the above problems, an object of the present disclosure is to provide an imaging control device that can set an appropriate shutter speed to suppress the occurrence of uneven brightness.

Means for Solving the Problems

[0006] The imaging control device of the present disclosure is an imaging control device that controls the operation of an imaging device, and determines an upper limit value of a shutter speed that can be set in the imaging device based on information regarding the flat light emission frequency of a light emitting device. [Effects of the Invention]

[0007] According to this disclosure, an imaging control device is realized that can suppress the occurrence of unevenness in brightness by setting an appropriate shutter speed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an imaging system according to the first embodiment. [Figure 2] This is a characteristic diagram illustrating the general relationship between flat-field emission and image capture by an image sensor in a camera. [Figure 3] This is a characteristic diagram showing the relationship between flat light emission when a switching element is switched at high speed and imaging by an image sensor in a camera. [Figure 4] This is a sequence diagram showing how the camera sets an upper limit on the shutter speed based on information acquired from the strobe in the imaging system of the first embodiment. [Figure 5] In the first embodiment, this is a flowchart that sets an upper limit on the shutter speed based on the flat flash frequency acquired by the camera from the strobe. [Figure 6] This is a flowchart illustrating a modified version of the first embodiment in which the camera sets an upper limit on the shutter speed based on the flat flash frequency acquired from the strobe. [Figure 7] In the second embodiment, the camera sets an upper limit on the shutter speed based on flag information obtained from the strobe, which indicates whether or not the flat flash frequency of the strobe is a predetermined high speed. [Figure 8] In a modified version of the second embodiment, the camera sets an upper limit on the shutter speed based on flag information obtained from the strobe indicating whether or not the flat flash frequency of the strobe is a predetermined high speed. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below with reference to the drawings. Note that the following embodiments do not limit the invention as defined in the claims. While multiple features are described in the embodiments, not all of these features are essential, and the features may be combined in any way. Furthermore, in the drawings, identical or similar configurations are given the same reference numeral, and redundant descriptions are omitted. The dimensions and structural details shown in each embodiment are not limited to those shown in the text and drawings.

[0010] -First Embodiment- The first embodiment will be described below.

[0011] [Configuration of the imaging system] Figure 1 is a schematic diagram showing an imaging system according to the first embodiment. The imaging system of this embodiment includes a camera 100 which is an imaging device, a lens 200 which is an optical device, and a strobe 300 which is a light-emitting device.

[0012] In Figure 1, a lens 200 is mounted on the front of the camera 100. The lens 200 is replaceable, and the camera 100 and the lens 200 are electrically connected via a mount contact group 103. A strobe 300 is mounted on the top of the camera 100. The strobe 300 is replaceable, and the camera 100 and the strobe 300 are electrically connected via a strobe contact group 109.

[0013] (Camera 100 configuration) First, let me explain the configuration of Camera 100.

[0014] The camera control unit 101 includes a CPU (microcomputer), which is a central processing unit, and comprehensively controls each part of the camera 100 and performs various settings according to a computer program loaded from the storage unit 110. The storage unit 110 stores the computer program that controls the camera control unit 101. In the imaging system shown in Figure 1, the imaging control device of this embodiment is configured with the camera control unit 101.

[0015] The imaging device 102 converts the light from the subject incident through the photographing lens 202 into an electrical signal to generate image data, and outputs it to the camera control unit 101.

[0016] The focal plane shutter 104 is disposed between the imaging device 102 and the photographing lens 202, and operates according to an instruction from the camera control unit 101. The focal plane shutter 104 includes a front curtain and a rear curtain. When the front curtain travels and the shutter opens, the exposure of the imaging device 102 starts. When the rear curtain travels and the shutter closes, the exposure of the imaging device 102 ends.

[0017] The camera operation unit 105 includes operation members operated by the user, detects the operations performed by the user via buttons, switches, dials, connected devices, etc. attached to the camera 100, and transmits a signal corresponding to the operation instruction to the camera control unit 101. The camera operation unit 105 outputs an instruction signal (hereinafter referred to as SW1 signal) issued when the user half-presses the release button and an instruction signal (hereinafter referred to as SW2 signal) issued when the user performs a full-press operation of deeply pressing the release button to the camera control unit 101.

[0018] The camera display unit 106 displays photographing information and a photographed image according to an instruction from the camera control unit 101.

[0019] The camera control unit 101 controls the operation of the camera 100 based on the output signal of the camera operation unit 105. When the output signal of the operation unit 105 is the SW1 signal, the camera control unit 101 drives the image sensor 102 to take an image, and repeatedly performs metering control (AE operation) to measure the brightness of the subject from the image result, and determines the shutter speed, aperture value, and ISO sensitivity to be used during shooting from the metering result. Here, the shutter speed, aperture value, and ISO sensitivity used during shooting are collectively called the exposure control value. The determined exposure control value is displayed on the screen of the camera display unit 106. When the output signal of the camera operation unit 105 is the SW2 signal, the camera control unit 101 drives the aperture in the shooting lens 202, sets the sensitivity (ISO sensitivity) of the image sensor 102, and controls the focal plane shutter 104 to illuminate the image sensor 102 with light. 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 image sensor 102, and also controls the writing of the image data to the image storage unit 107.

[0020] In this embodiment, the camera control unit 101 obtains information regarding the flat emission frequency of the strobe 300 from the strobe control unit 301 via the strobe contact group 109. Based on the obtained information regarding the flat emission frequency, the camera control unit 101 determines the upper limit of the configurable shutter speed for the focal plane shutter 104. The information regarding the flat emission frequency is either the flat emission frequency of the strobe 300 or flag information for the flat emission frequency of the strobe 300.

[0021] If the information regarding the flat emission frequency is the flat emission frequency of the strobe 300, the camera control unit 101 determines the upper limit of the shutter speed based on the relationship between the flat emission frequency of the strobe 300 and a predetermined threshold. Specifically, if the flat emission frequency is less than the threshold, the upper limit of the shutter speed is set to a first value (for example, shspdmax1 in this embodiment). If the flat emission frequency is greater than or equal to the threshold, the upper limit of the shutter speed is set to a second value that is faster than the first value (for example, shspdmax2 in this embodiment). Note that if the camera control unit 101 cannot obtain the flat emission frequency, it may set the upper limit of the shutter speed to the first value.

[0022] The camera control unit 101 may determine the upper limit of the shutter speed based on the relationship between the flat flash frequency of the strobe 300 and a predetermined threshold, and the efficiency of the shutter type set for the focal plane shutter 104.

[0023] On the other hand, if the information regarding the flat flash frequency is flag information for the flat flash frequency of the strobe 300, the following occurs. The camera control unit 101 determines the upper limit of the shutter speed based on whether the flag information corresponds to a value when the flat flash frequency of the strobe 300 is a predetermined high speed. Specifically, if the flag information is the value when it is determined that the flat flash frequency of the strobe 300 is not a predetermined high speed, the upper limit of the shutter speed is set to the first value (for example, shspdmax1 in the second embodiment). If the flag information is the value when it is determined that the flat flash frequency of the strobe 300 is a predetermined high speed, the upper limit of the shutter speed is set to the second value which is faster than the first value (for example, shspdmax2 in the second embodiment). Note that if the camera control unit 101 cannot obtain the flag information, it may set the upper limit of the shutter speed to the first value.

[0024] The camera control unit 101 may determine the upper limit of the shutter speed based on the determination of the flat flash frequency of the strobe 300 in the flag information and the efficiency of the shutter type set for the focal plane shutter 104.

[0025] In this embodiment, the camera control unit 101 directly obtains information regarding the flat emission frequency of the strobe 300 from the strobe 300, but this is not the only example. For example, the camera control unit 101 may obtain a signal from the strobe 300 to recognize the strobe, and based on that signal, refer to a table or the like stored in the memory unit 110 or the like to obtain information regarding the flat emission frequency of the strobe 300.

[0026] In the camera 100 of this embodiment, the photographer can selectively set the shutter method of the focal plane shutter 104. Specifically, all or part of the mechanical shutter method, electronic shutter method, and electronic front curtain shutter method, or in this case all of them, can be appropriately set as the shutter method. The mechanical shutter method controls the opening and closing of the focal plane shutter 104 to control the exposure of the image sensor 102. The electronic shutter method controls the exposure by electronic control inside the image sensor 102 while the focal plane shutter 104 remains open. The electronic front curtain shutter method controls the front curtain shutter by electronic control inside the image sensor 102, and after a predetermined period of time, closes the rear curtain of the focal plane shutter 104 to end the exposure.

[0027] The camera power supply unit 108 includes a battery and consists of an electrical circuit for supplying power to various parts of the camera 100.

[0028] (Lens 200 configuration) Next, I will explain the configuration of lens 200.

[0029] The lens control unit 201 includes a CPU (microcomputer), which is a central processing unit, and controls the operation of each part of the lens 200. The photographic lens 202 is composed of multiple lenses and forms an image of the subject on the image sensor 102. Furthermore, the photographic lens 202 is provided with an aperture 203 for adjusting the amount of light and a focus lens (not shown) for adjusting the focus.

[0030] The lens control unit 201 adjusts the amount of light taken into the camera and the focus, according to instructions from the camera control unit 101, via control through the mount contact group 103.

[0031] (Configuration of Strobe 300) Next, I will explain the configuration of the Strobe 300.

[0032] The strobe control unit 301 includes a CPU (microcomputer), which is a central processing unit, and controls the operation of each part of the strobe 300. The strobe control unit 301 can communicate with the camera control unit 101 via the strobe contact group 109, and can receive flash control instructions and camera information from the camera, and transmit strobe information. The flash-emitting unit 302 consists of a discharge tube, a flash-emitting circuit, and a flash-emitting optical system.

[0033] The charging unit 305 uses power from a battery (not shown) mounted on the strobe 300 to charge a capacitor (not shown) with energy to generate illumination light for the subject being photographed. The charging operation is controlled by the strobe control unit 301, which detects the voltage charged in the capacitor and stops the charging operation when the voltage exceeds a predetermined voltage threshold (charging complete). The strobe control unit 301 also starts the charging operation when the voltage falls below a predetermined voltage threshold. The charging voltage and charging complete flag information are transmitted to the camera control unit 101 via the strobe contact group 109.

[0034] The strobe control unit 303 is equipped with operating components operated by the user. It detects operations performed by the user via buttons, dials, etc., attached to the strobe body unit 300 and sends a signal corresponding to the operation instruction to the strobe control unit 301. The strobe display unit 304 displays the flashing mode, etc., according to the instructions of the strobe control unit 301.

[0035] The strobe power supply unit 307 includes a battery and consists of an electrical circuit for supplying power to each part of the strobe 300.

[0036] The strobe control unit 301 drives the light-emitting circuit 308, which includes a switching element 309, and releases the energy charged in the light-emitting capacitor into the discharge tube, causing the light-emitting unit 302 to emit light, which then illuminates the subject through the light-emitting optical system.

[0037] The strobe control unit 301 performs predetermined control on the light emission circuit 308, and when the switching element 309 is turned on, the light emission unit 302 emits light. Subsequently, when the switching element 309 is turned off, the light emission stops. The control signal for the switching element 309 is set to swpulse.

[0038] Light emission can be performed in two ways: a flash emission, where the switching element 309 is turned on once, and a flat emission, where the switching element 309 is repeatedly controlled to turn on and off. The amount of light emitted from the light-emitting unit 302 is observed by the strobe control unit 301 via the photocurrent detection unit 306, and when a predetermined amount of light is detected, the light emission stops. The photocurrent detection unit is equipped with a photodetector diode and a circuit that integrates the current generated from the photodetector diode and converts it into a voltage. During flash emission, the strobe control unit 301 determines whether a predetermined amount of light has been emitted by comparing the photocurrent or the integrated voltage of the photocurrent with a predetermined threshold.

[0039] In flat flash mode, the strobe control unit 301 compares the photocurrent with a predetermined peak threshold to determine whether a predetermined amount of light has been emitted, and turns off the switching element. When the switching element is turned off, the light intensity decreases. The strobe control unit 301 compares the photocurrent with a predetermined bottom threshold to determine whether the light intensity has decreased to a predetermined level, and turns on the switching element. By repeatedly controlling the on / off state of the switching element 309 in this way, a flat-like flash is produced. The duration of the flat flash is determined by the camera 100 according to the set shutter speed, and is controlled by communicating with the strobe 300.

[0040] An example of a switching element 309 is an IGBT (Insulated Gate Bipolar Transistor). IGBTs are commonly used as switching elements in strobes. The switching frequency at which IGBTs can operate is approximately 50 kHz. Therefore, during flat flash, a difference in light intensity occurs at a frequency of 50 kHz.

[0041] Figure 2 illustrates the general relationship between flat-field emission and imaging by an image sensor in a camera. The flash waveform of the strobe repeatedly changes between bright and dark according to the on / off state of the control signal swpulse of the switching element. In Figure 2, the image sensor portion shows the exposure period for each row of the photoelectric conversion section within the image sensor in the camera. The exposure period for each row is based on the shutter speed set in the camera. In Figure 2, comparing the flash waveforms during the exposure period of row 102m of the image sensor and row 102n of the image sensor, the flash waveform during the period when row 102m is exposed is darker than the flash waveform during the period when row 102n is exposed. As a result, horizontal bands appear in the captured image due to the difference in brightness of the flat flash. This is particularly noticeable when the shutter speed is fast.

[0042] In contrast, the above-mentioned problems can be resolved by using SiC (silicon carbide) or GaN (gallium nitride) as the switching element (switching element 309 in this embodiment). These switching elements have lower conduction losses compared to IGBTs and can be switched at higher frequencies than IGBTs.

[0043] Figure 3 is a characteristic diagram showing the relationship between flat light emission and imaging by the image sensor 102 in the camera 100 when the switching element 309 is switched at high speed. In Figure 3, the shutter speed is set to the same value as in Figure 2, and the exposure period for each row is also the same as in Figure 2. As shown in Figure 3, the switching occurs multiple times within the exposure period for each row of the image sensor 102. Therefore, the strobe light that exposes each row becomes uniform, and horizontal banding caused by differences in brightness in the flat light emission is suppressed.

[0044] [Imaging control in the first embodiment] The imaging control in this embodiment will be described below.

[0045] Figure 4 is a sequence diagram showing how the camera 100 sets the upper limit of the shutter speed based on information acquired from the strobe 300 in the imaging system of this embodiment. Here, high-speed sync shooting is enabled by the user's settings, and it is possible to set a shutter speed that exceeds the strobe sync speed.

[0046] First, in step S400, the camera 100 transmits a signal to the strobe 300 requesting information regarding the flat emission frequency. In this embodiment, the information regarding the flat emission frequency is the switching frequency (flat emission frequency) itself when the strobe 300 emits a flat flash. Hereinafter, this information will simply be referred to as the "flat emission frequency".

[0047] In step S401, the strobe 300 receives a signal from the camera 100 and transmits information regarding the flat flash frequency.

[0048] In step S402, the camera 100 sets an upper limit for the shutter speed based on information regarding the flat flash frequency obtained from the strobe 300.

[0049] Figure 5 is a flowchart showing how, in this embodiment, the camera 100 sets the upper limit of the shutter speed based on the flat flash frequency acquired from the strobe 300. In step S500, the camera control unit 101 receives a flat flash frequency from the strobe 300. This flat flash frequency is denoted as freqFP.

[0050] In Figure 4, if a strobe that cannot acquire a flat flash frequency is attached, the camera control unit 101 sets freqFP to a value smaller than the judgment threshold freqTh described later. That is, if a strobe that cannot acquire a flat flash frequency is attached, the processing proceeds as if the flat flash frequency is low.

[0051] In step S501, the camera control unit 101 determines whether the flat emission frequency freqFP received from the strobe 300 is smaller than a predetermined determination threshold freqTh.

[0052] If, in step S501, it is determined that the flat emission frequency freqFP is smaller than the determination threshold freqTh, then in step S502, the camera control unit 101 determines the shutter speed upper limit shspdmax to shspdmax1.

[0053] On the other hand, if it is determined in step S501 that the flat emission frequency freqFP is greater than or equal to the determination threshold freqTh, the following processing is performed in step S502. The camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax2, which is faster than shspdmax1.

[0054] Once the shutter speed upper limit value shspdmax is determined, the camera control unit 101 terminates the flow for setting the shutter speed upper limit.

[0055] The camera control unit 101 performs various controls based on the determined shutter speed upper limit. In shutter-priority mode and manual exposure mode, where the user can set the shutter speed, the control unit restricts the user from setting a shutter speed that exceeds the upper limit. In aperture-priority mode and program AE mode, where the camera sets the shutter speed, the control unit prevents the shutter speed from exceeding the upper limit.

[0056] As described above, according to this embodiment, by acquiring the flat emission frequency of the strobe 300, it is possible to set an appropriate upper limit for the shutter speed, thereby realizing a camera 100 that can suppress the occurrence of unevenness in brightness.

[0057] -Variations- Modified examples of this embodiment will be described below. The configuration of the imaging system in this modified example is the same as that shown in Figure 1 of this embodiment. In this modified example, in addition to determining the relationship between the flat emission frequency of the strobe 300 and a predetermined threshold, the shutter efficiency is determined by identifying the set shutter method, thereby determining the upper limit of the shutter speed in the camera 100.

[0058] [Imaging control in a modified example of the first embodiment] The imaging control in this modified example will be explained below.

[0059] Figure 6 is a flowchart showing how, in this modified example, the camera 100 sets the upper limit of the shutter speed based on the flat flash frequency acquired from the strobe 300. In step S600, the camera control unit 101 receives a flat emission frequency from the strobe 300. This flat emission frequency is denoted as freqFP.

[0060] Similar to this embodiment, in Figure 4, if a strobe that cannot acquire a flat flash frequency is attached, the camera control unit 101 sets freqFP to a value smaller than the judgment threshold freqTh described later. That is, if a strobe that cannot acquire a flat flash frequency is attached, the processing proceeds as if the flat flash frequency is low.

[0061] In step S601, the camera control unit 101 determines whether the flat emission frequency freqFP received from the strobe 300 is smaller than a predetermined determination threshold freqTh.

[0062] In step S601, if freqFP is less than a predetermined threshold freqTh, the camera control unit 101 proceeds to step S602. If freqFP is greater than or equal to the predetermined threshold freqTh, the camera control unit 101 proceeds to step S603.

[0063] If freqFP is smaller than a predetermined threshold freqTh in step S601, in step S602, the camera control unit 101 determines whether the shutter method set for the focal plane shutter 104 is an electronic shutter method.

[0064] If, in step S602, it is determined that the shutter type set for the focal plane shutter 104 is not an electronic shutter (it is a mechanical shutter or an electronic front curtain shutter), the process proceeds to step S604. In step S604, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax1.

[0065] On the other hand, if it is determined in step S602 that the shutter type set for the focal plane shutter 104 is an electronic shutter, the process proceeds to step S605. In step S605, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax2.

[0066] If freqFP is greater than or equal to a predetermined threshold freqTh in step S601, in step S603, the camera control unit 101 determines whether or not the shutter method set for the focal plane shutter 104 is an electronic shutter method.

[0067] If, in step S603, it is determined that the shutter type set for the focal plane shutter 104 is not an electronic shutter (it is a mechanical shutter or an electronic front curtain shutter), the process proceeds to step S606. In step S606, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax3.

[0068] On the other hand, if it is determined in step S603 that the shutter type set for the focal plane shutter 104 is an electronic shutter, the process proceeds to step S607. In step S607, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax4.

[0069] When the flat flash frequency is high, the shutter speed can be set to a faster value. Therefore, shspdmax3 is a faster value than shspdmax1. Similarly, shspdmax4 is a faster value than shspdmax2.

[0070] Furthermore, electronic shutter systems offer better shutter efficiency compared to mechanical shutter systems. Therefore, when the flat flash frequency is low, electronic shutter systems are more prone to unevenness caused by differences in brightness during the flat flash. Consequently, shspdmax1 for mechanical or electronic front curtain shutter systems will be faster than shspdmax2 for electronic shutter systems. On the other hand, when the flat flash frequency is sufficiently high, even with electronic shutter systems, unevenness caused by differences in brightness during the flat flash is less likely to occur. Generally, electronic shutter systems allow for faster shutter speeds than mechanical shutter systems, so shspdmax3 for mechanical or electronic front curtain shutter systems will be slower than shspdmax4 for electronic shutter systems.

[0071] Based on the above, in this modified example, the relative magnitudes of the shutter speed upper limit values ​​shspdmax are as follows. shspdmax4>shspdmax3>shspdmax1>shspdmax2

[0072] Furthermore, the relationship between shutter speed and other factors is not limited to those mentioned above, but is determined by the flat flash frequency and the performance of each shutter type.

[0073] Once the shutter speed upper limit value shspdmax is determined, the camera control unit 101 terminates the flow for setting the shutter speed upper limit.

[0074] In Figure 6, the determination in steps S602 and S603 is made to determine whether or not it is an electronic shutter, and the same shutter speed limit is set for both the mechanical shutter system and the electronic front curtain shutter system. Alternatively, the determination could be made separately for the mechanical shutter system and the electronic front curtain shutter system, and different shutter speed limits could be set.

[0075] As explained above, this modified version allows for the setting of an appropriate upper limit for shutter speed by acquiring the flat flash frequency of the strobe 300 and determining the shutter performance for the set shutter method. This enables the realization of a camera 100 that can suppress the occurrence of uneven lighting.

[0076] -Second Embodiment- The second embodiment will now be described. The configuration of the imaging system in this embodiment is the same as in Figure 1 shown in this embodiment. In this embodiment, as information regarding the flat flash frequency, flag information is used that indicates whether or not the flat flash frequency of the strobe 300 corresponds to a predetermined high speed. In this embodiment as well, high-speed sync shooting is enabled by the user's settings, and it is possible to set a shutter speed that exceeds the strobe sync speed.

[0077] In this embodiment, the information regarding the flat emission frequency acquired by the camera 100 in S401 of Figure 4 is flag information indicating whether or not the flat emission frequency of the strobe 300 is a predetermined high speed. Figure 7 is a flowchart showing how, in this embodiment, the camera 100 sets an upper limit on the shutter speed based on flag information obtained from the strobe 300, which indicates whether or not the flat emission frequency of the strobe 300 is a predetermined high speed.

[0078] In step S700, the camera control unit 101 receives flag information from the strobe 300 indicating whether the flat flash frequency is a predetermined high speed. This flag information is denoted as FlagFreqHigh. If the flat flash frequency is high speed, FlagFreqHigh is "1", and if the flat flash frequency is not high speed, FlagFreqHigh is "0".

[0079] In Figure 4, if a strobe that cannot acquire flag information is attached, the camera control unit 101 sets FlagFreqHigh to "0". In other words, if a strobe that cannot acquire flag information is attached, the processing proceeds as if the flat flash frequency is low.

[0080] In step S701, the camera control unit 101 determines whether the FlagFreqHigh received from the strobe 300 is "1".

[0081] If in step S701 it is determined that FlagFreqHigh is not "1" (i.e., "0"), meaning the flat flash frequency is not high, the process proceeds to step S702. In step S702, the camera control unit 101 determines the shutter speed upper limit shspdmax to shspdmax1.

[0082] On the other hand, if FlagFreqHigh is determined to be "1" in step S701, that is, if the flat flash frequency is high, the process proceeds to step S703. In step S703, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax2, which is faster than shspdmax1.

[0083] Once the shutter speed upper limit value shspdmax is determined, the camera control unit 101 terminates the flow for setting the shutter speed upper limit.

[0084] As described above, according to this embodiment, by obtaining flag information from the strobe 300 indicating whether or not the flat flash frequency is high, an appropriate upper limit for the shutter speed can be set. This enables the camera 100 to suppress the occurrence of unevenness in brightness.

[0085] -Variations- The following describes some modified examples of this embodiment. The configuration of the imaging system in this modified example is the same as that shown in Figure 1 of this embodiment. In this modified example, in addition to determining the flat emission frequency of the strobe 300 in the flag information, the shutter efficiency is determined by identifying the set shutter method, thereby determining the upper limit of the shutter speed in the camera 100.

[0086] [Image control in a modified example of the second embodiment] The imaging control in this modified example will be explained below. Figure 8 is a flowchart in this modified example showing how the camera 100 sets the upper limit of the shutter speed based on flag information acquired from the strobe 300, which indicates whether or not the flat flash frequency of the strobe 300 is a predetermined high speed.

[0087] In step S800, the camera control unit 101 receives flag information from the strobe 300 indicating whether the flat flash frequency is a predetermined high speed. This flag information is denoted as FlagFreqHigh. If the flat flash frequency is high speed, FlagFreqHigh is "1", and if the flat flash frequency is not high speed, FlagFreqHigh is "0".

[0088] In Figure 4, if a strobe that cannot acquire flag information is attached, the camera control unit 101 sets FlagFreqHigh to "0". In other words, if a strobe that cannot acquire flag information is attached, the processing proceeds as if the flat flash frequency is low.

[0089] In step S801, the camera control unit 101 determines whether the FlagFreqHigh received from the strobe 300 is "1".

[0090] If in step S801 it is determined that FlagFreqHigh is not "1" (i.e., "0"), meaning the flat emission frequency is not high, the camera control unit 101 proceeds to step S802. On the other hand, if in step S801 it is determined that FlagFreqHigh is "1", meaning the flat emission frequency is high, the camera control unit 101 proceeds to step S803.

[0091] In step S802, similar to step S602 in Figure 6 of the first embodiment, the camera control unit 101 determines whether the shutter method set for the focal plane shutter 104 is an electronic shutter method.

[0092] If, in step S802, it is determined that the shutter type set for the focal plane shutter 104 is not an electronic shutter (it is a mechanical shutter type or an electronic front curtain shutter type), the process proceeds to step S804. In step S804, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax1.

[0093] On the other hand, if it is determined in step S802 that the shutter type set for the focal plane shutter 104 is an electronic shutter, the process proceeds to step S805. In step S805, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax2.

[0094] In step S803, the camera control unit 101 determines whether the set shutter method is an electronic shutter method.

[0095] If, in step S803, it is determined that the shutter type set for the focal plane shutter 104 is not an electronic shutter (it is a mechanical shutter type or an electronic front curtain shutter type), the process proceeds to step S806. In step S806, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax3.

[0096] On the other hand, if it is determined in step S803 that the shutter type set for the focal plane shutter 104 is an electronic shutter, the process proceeds to step S807. In step S807, the camera control unit 101 sets the shutter speed upper limit shspdmax to shspdmax4.

[0097] In this modified example, similar to the modified example of the first embodiment, the relative magnitudes of the shutter speed upper limit values ​​shspdmax are as follows. shspdmax4>shspdmax3>shspdmax1>shspdmax2

[0098] Once the shutter speed upper limit value shspdmax is determined, the camera control unit 101 terminates the flow for setting the shutter speed upper limit.

[0099] As explained above, this modified version acquires flag information from the strobe 300 indicating whether or not it is faster than a predetermined flat flash frequency, and determines the shutter performance for the set shutter method. This makes it possible to set an appropriate upper limit for the shutter speed, resulting in a camera 100 that can suppress the occurrence of unevenness in brightness.

[0100] -Other Embodiments- In the embodiments described above, a storage medium such as the memory unit 110 stores a computer program for controlling the imaging system. This computer program is a control program for realizing the various functions of the CPU of the camera control unit 101. Specifically, each step corresponds to the program as shown in Figures 5 to 8. In Figure 5, steps S500 to S503 are represented; in Figure 6, steps S600 to S607; in Figure 7, steps S700 to S703; and in Figure 8, steps S800 to S807. The CPU of the camera control unit 101, acting as a computer, reads the computer program from the storage medium such as the memory unit 110 and executes it. The embodiments can also be realized by supplying this computer program to a system or device via a network or storage medium, and having one or more processors in the computer of that system or device read and execute the program. They can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions. The program code read from the recording medium itself realizes the functions of the embodiments described above, and the recording medium on which the program code is recorded constitutes the present disclosure.

[0101] While preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence.

[0102] The disclosure of various embodiments includes the following configurations, methods, and programs. (Composition 1) An imaging control device that controls the operation of an imaging device, Based on information regarding the flat emission frequency of the light-emitting device, the upper limit of the configurable shutter speed in the imaging device is determined. Image capture control device. (Configuration 2) Information regarding the flat emission frequency is obtained from the light-emitting device. The imaging control device described in Configuration 1. (Composition 3) The information relating to the flat emission frequency is the flat emission frequency of the light-emitting device. An imaging control device according to configuration 1 or 2. (Composition 4) The upper limit of the shutter speed is determined based on the relationship between the flat emission frequency and a predetermined threshold. The imaging control device described in Configuration 3. (Composition 5) If the flat emission frequency is smaller than the threshold, the upper limit of the shutter speed is set to the first value. If the flat emission frequency is greater than or equal to the threshold, the upper limit of the shutter speed is set to a second value that is faster than the first value. The imaging control device described in Configuration 4. (Composition 6) If the flat emission frequency of the light-emitting device cannot be obtained, the upper limit of the shutter speed shall be set to the first value. The imaging control device described in configuration 5. (Composition 7) The upper limit of the shutter speed is determined by the relationship between the flat emission frequency and a predetermined threshold, and by identifying the set shutter type. The imaging control device described in Configuration 3. (Composition 8) The shutter system can be selectively set to include all or some of the following: mechanical shutter system, electronic shutter system, and electronic front curtain shutter system. The imaging control device described in Configuration 7. (Composition 9) If the flat emission frequency of the light-emitting device cannot be obtained, the upper limit of the shutter speed is determined based on the case where the flat emission frequency is smaller than a predetermined threshold. The imaging control device described in configuration 7 or 8. (Composition 10) The information relating to the flat emission frequency is the flag information of the flat emission frequency of the light-emitting device. An imaging control device according to configuration 1 or 2. (Composition 11) The upper limit of the shutter speed is determined based on whether the flag information corresponds to a value when the flat emission frequency of the light-emitting device is a predetermined high speed. The imaging control device described in configuration 10. (Composition 12) If the flag information is the value at which it is determined that the flat emission frequency of the light-emitting device is not the predetermined high speed, the upper limit of the shutter speed is set to the first value. If the flag information is the value at which the flat emission frequency of the light-emitting device is determined to be the predetermined high speed, the upper limit of the shutter speed is set to a second value that is faster than the first value. The imaging control device described in configuration 11. (Composition 13) If the aforementioned flag information cannot be obtained, the upper limit of the shutter speed shall be set to the first value. The imaging control device described in configuration 12. (Composition 14) The upper limit of the shutter speed is determined by determining the flat emission frequency of the light-emitting device in the flag information and identifying the set shutter type. The imaging control device described in configuration 10. (Composition 15) The shutter system can be selectively set to include all or some of the following: mechanical shutter system, electronic shutter system, and electronic front curtain shutter system. The imaging control device described in configuration 14. (Composition 16) If the aforementioned flag information cannot be obtained, the upper limit of the shutter speed is determined based on the flag information indicating that the flat emission frequency of the light-emitting device is not a predetermined high speed. The imaging control device described in configuration 14 or 15. (Method 1) An imaging control method for controlling the operation of an imaging device, Based on information regarding the flat emission frequency of the light-emitting device, the upper limit of the configurable shutter speed in the imaging device is determined. Image control method. (Program 1) The computer of the imaging control device, A control program that causes the imaging device to determine the upper limit of the configurable shutter speed based on information regarding the flat emission frequency of the light-emitting device. [Explanation of Symbols]

[0103] 100 Cameras 101 Camera Control Unit 102 Image sensor 103 Mounting contact group 104 Focal-plane shutter 105 Camera control unit 106 Camera display unit 107 Image storage unit 108 Camera Power Supply Unit 109 Strobe contact group 110 Storage section 200 lenses 201 Lens Control Unit 300 strobe 301 Strobe Control Unit

Claims

1. An imaging control device that controls the operation of an imaging device, Based on information regarding the flat emission frequency of the light-emitting device, the upper limit of the configurable shutter speed in the imaging device is determined. Image capture control device.

2. Information regarding the flat emission frequency is obtained from the light-emitting device. The imaging control device according to claim 1.

3. The information relating to the flat emission frequency is the flat emission frequency of the light-emitting device. The imaging control device according to claim 1 or 2.

4. The upper limit of the shutter speed is determined based on the relationship between the flat emission frequency and a predetermined threshold. The imaging control device according to claim 3.

5. If the flat emission frequency is smaller than the threshold, the upper limit of the shutter speed is set to the first value. If the flat emission frequency is greater than or equal to the threshold, the upper limit of the shutter speed is set to a second value that is faster than the first value. The imaging control device according to claim 4.

6. If the flat emission frequency of the light-emitting device cannot be obtained, the upper limit of the shutter speed shall be set to the first value. The imaging control device according to claim 5.

7. The upper limit of the shutter speed is determined by the relationship between the flat emission frequency and a predetermined threshold, and by identifying the set shutter type. The imaging control device according to claim 3.

8. The shutter system can be selectively set to include all or some of the following: mechanical shutter system, electronic shutter system, and electronic front curtain shutter system. The imaging control device according to claim 7.

9. If the flat emission frequency of the light-emitting device cannot be obtained, the upper limit of the shutter speed is determined based on the case where the flat emission frequency is smaller than a predetermined threshold. The imaging control device according to claim 7.

10. The information relating to the flat emission frequency is the flag information of the flat emission frequency of the light-emitting device. The imaging control device according to claim 1 or 2.

11. The upper limit of the shutter speed is determined based on whether the flag information corresponds to a value when the flat emission frequency of the light-emitting device is a predetermined high speed. The imaging control device according to claim 10.

12. If the flag information is the value at which it is determined that the flat emission frequency of the light-emitting device is not the predetermined high speed, the upper limit of the shutter speed is set to the first value. If the flag information is the value at which the flat emission frequency of the light-emitting device is determined to be the predetermined high speed, the upper limit of the shutter speed is set to a second value that is faster than the first value. The imaging control device according to claim 11.

13. If the aforementioned flag information cannot be obtained, the upper limit of the shutter speed shall be set to the first value. The imaging control device according to claim 12.

14. The upper limit of the shutter speed is determined by determining the flat emission frequency of the light-emitting device in the flag information and identifying the set shutter type. The imaging control device according to claim 10.

15. The shutter system can be selectively set to include all or some of the following: mechanical shutter system, electronic shutter system, and electronic front curtain shutter system. The imaging control device according to claim 14.

16. If the aforementioned flag information cannot be obtained, the upper limit of the shutter speed is determined based on the flag information indicating that the flat emission frequency of the light-emitting device is not a predetermined high speed. The imaging control device according to claim 14.

17. An imaging control method for controlling the operation of an imaging device, Based on information regarding the flat emission frequency of the light-emitting device, the upper limit of the configurable shutter speed in the imaging device is determined. Image control method.

18. The computer of the imaging control device, A control program that causes the imaging device to determine the upper limit of the configurable shutter speed based on information regarding the flat emission frequency of the light-emitting device.

Images