JP2011035718A - Imaging apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus for properly executing exposure control without impairing focusing accuracy even when executing autofocus control and automatic exposure control in parallel to follow a subject. <P>SOLUTION: The imaging apparatus includes: a first exposure control mode; and a second exposure control mode in which a settable maximum exposure time is shorter than that of the first exposure mode. In a photographing standby state, the apparatus switches the exposure control mode from the first exposure control mode to the second exposure control mode, and executes exposure control. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to exposure control of an imaging apparatus, particularly a digital camera.

  Some conventional digital cameras perform exposure control to increase the exposure time in order to obtain a sufficient signal level when the subject is dark. However, when performing autofocus control based on a signal acquired by extending the exposure time, there may be a problem that appropriate autofocus control cannot be performed depending on the length of the exposure time. For example, Patent Document 1 aims to solve the problem that focusing is difficult when focusing is performed in a state where the frame rate is lowered in order to increase the exposure time, or it takes time to focus. In order to solve the above-mentioned problem, in Japanese Patent Laid-Open No. 2004-260260, an imaging apparatus is disclosed in which when the subject is dark, the frame rate is set to a normal state when focusing and then returned to a low frame rate.

JP 2001-203931 A

  However, when the autofocus control and the automatic exposure control are performed in parallel with the subject, the following problem occurs in the configuration of the cited document 1.

  Note that the case where the autofocus control and the automatic exposure control are performed in parallel while following the subject includes a period from when the shooting preparation process start instruction is issued until the shooting process start instruction is issued. Normally, when the shutter button is pressed halfway and an instruction to start shooting preparation processing is given, autofocus control and autoexposure control are performed to determine the proper focus and exposure for the subject. After that, if the subject moves between when the shutter button is fully pressed and the shooting process is instructed, the focus and exposure determined when the shutter button is pressed halfway may not be appropriate. . For this reason, if the focus and exposure are to be adjusted appropriately, autofocus control and automatic exposure control must be performed again when the shutter button is fully pressed, resulting in a release time lag. Alternatively, if the image is taken with the focus and exposure determined when the shutter button is half-pressed, a failed image is obtained. Therefore, after an instruction to start the shooting preparation process is given, the subject is followed and autofocus control and automatic exposure control are performed in parallel, so that a release time lag can be suppressed and an appropriate image can be shot.

  As in the cited document 1, when the autofocus control is performed, the normal frame rate is set, and in other cases, the frame rate is controlled to be a low frame rate. For example, if the subject suddenly moves in a state where the frame rate is lowered and the exposure time is lengthened to perform automatic exposure control, appropriate autofocus control cannot be performed while the frame rate is lowered, and focusing is performed. I can't. Therefore, in order to perform focusing, autofocus control must be performed after switching the frame rate to the normal frame rate, and there is a problem that the followability of focusing on the subject is delayed.

  In addition, regardless of the frame rate switching, if the exposure time when acquiring the signal used for autofocus control is too long, the degree of image blur that occurs during exposure will increase, and autofocus control will be performed accurately. The problem of not being able to occur.

  On the other hand, when maintaining a short exposure time in order to prioritize the accuracy of autofocus control, depending on the subject brightness, the exposure time cannot be lengthened, so that the exposure cannot be controlled so as to achieve an appropriate exposure.

  The present invention has been made in view of the above problems, and an object thereof is to provide an imaging apparatus capable of performing appropriate autofocus control and performing exposure control in accordance with subject brightness.

  In order to achieve the above object, an imaging apparatus according to the present invention includes an imaging unit that captures an image of a subject and acquires image data, and a photometric unit that acquires a photometric value based on the image data acquired by the imaging unit. A first exposure control mode, and a second exposure control mode in which the longest exposure time that can be set is shorter than that of the first exposure control mode, and the first exposure control mode and the second exposure control. Exposure control means for performing exposure control based on the photometric value acquired by the photometry means in any exposure control mode of the mode, and the exposure control means sets the exposure control mode to Exposure control is performed by switching from the first exposure control mode to the second exposure control mode.

  According to the present invention, it is possible to perform appropriate autofocus control and exposure control according to subject brightness.

1 is a block diagram of an imaging apparatus according to an embodiment of the present invention. It is a flowchart figure which shows the whole operation | movement of the imaging device which concerns on the Example of this invention. It is a flowchart figure of the still image recording mode process which concerns on the Example of this invention. It is a flowchart figure of the still image recording mode process which concerns on the Example of this invention. It is a flowchart figure of the still image recording mode process which concerns on the Example of this invention. It is a flowchart figure of the still image recording mode process which concerns on the Example of this invention. It is a flowchart figure of the servo AE determination process based on the Example of this invention. It is a flowchart figure of the servo AE information storage process based on the Example of this invention. It is a flowchart figure of the still image exposure calculation process for servo AE which concerns on the Example of this invention. It is a flowchart figure of SW1 exposure calculation processing for servo AE which concerns on the Example of this invention. It is a flowchart figure of the imaging | photography process which concerns on the Example of this invention. It is an example of the program diagram for still pictures concerning the example of the present invention. It is an example of the program diagram for still pictures and the program diagram for SW1 exposure which concern on the Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 100 denotes an imaging device. Reference numeral 10 denotes a photographing lens, and reference numeral 12 denotes a shutter having an aperture function. The shutter 12 also includes an ND filter provided separately from the aperture. The amount of light received by the image sensor 14 can be changed by controlling the shutter 12.

  An image sensor 14 converts an optical image into an electric signal, and an A / D converter 16 converts an analog signal output from the image sensor 14 into a digital signal. The A / D converter 16 also includes a gain circuit that amplifies the analog signal output of the image sensor 14. The gain increase amount of the signal can be changed by controlling the gain circuit according to the set ISO sensitivity or the like.

  A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control unit 50. By controlling the timing generation circuit 18, electronic shutter control is possible, and the exposure time can be changed.

  An image processing unit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D conversion unit 16 or the data from the memory control circuit 22. The image processing unit 20 performs predetermined calculation processing using the captured image data, and the system control unit 50 controls the exposure control unit 40 and the focus control unit 42 based on the obtained calculation result. Do. Specifically, TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash pre-flash) processing are performed. Further, the image processing unit 20 performs predetermined arithmetic processing using the captured image data, and performs TTL AWB (auto white balance) processing based on the obtained arithmetic result. In addition, the image processing unit 20 includes a face detection circuit, performs face detection on the data from the A / D conversion unit 16 or the data from the memory control circuit 22, and performs system control on information relating to the detected face area. Notify unit 50.

  A memory control circuit 22 controls the A / D conversion unit 16, the timing generation circuit 18, the image processing unit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression unit 32. The data of the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processor 20 and the memory control circuit 22 or the data of the A / D converter 16 is directly passed through the memory control circuit 22. It is.

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, 28 denotes an image display unit including a TFT LCD, and the image data for display written in the image display memory 24 passes through the D / A converter 26. Displayed by the image display unit 28. An electronic viewfinder function (live view function) can be realized by sequentially displaying image data captured using the image display unit 28. The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control unit 50. When the display is turned off, the power consumption of the imaging apparatus 100 can be significantly reduced. it can.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity to store a predetermined number of still images and a predetermined time of moving images. This makes it possible to write a large amount of images to the memory 30 at high speed even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot. The memory 30 can also be used as a work area for the system control unit 50.

  Reference numeral 32 denotes a compression / decompression unit that compresses and decompresses image data by adaptive discrete cosine transform (ADCT), wavelet transform, etc., and reads the image stored in the memory 30 to perform compression processing or decompression processing. Is written into the memory 30. Reference numeral 34 denotes an encryption / decryption circuit that performs encryption processing on image data that has been photographed and stored in a predetermined area of the memory 30 as necessary, and that has been encrypted and stored in the predetermined area of the memory 30. Decoding processing is performed when image data is reproduced and displayed.

  Reference numeral 40 denotes an exposure control means for controlling the shutter 12 having a diaphragm function, and has a flash light control function in cooperation with the flash 48. Reference numeral 42 denotes focus control means for controlling the focusing of the photographing lens 10, reference numeral 44 denotes zoom control means for controlling zooming of the photographing lens 10, and reference numeral 46 denotes barrier control means for controlling the operation of the lens barrier 102 serving as protection means. A flash 48 has an AF auxiliary light projecting function and a flash light control function.

  The exposure control means 40 and the focus control means 42 are controlled using the TTL method, and the system control unit 50 uses the exposure control means 40 and the focus control means based on the calculation result obtained by calculating the captured image data by the image processing unit 20. 42 is controlled.

  Reference numeral 50 denotes a system control unit that controls the entire imaging apparatus 100, and reference numeral 52 denotes a memory that stores constants, variables, programs, and the like for operation of the system control unit 50.

  Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker that displays an operation state, a message, or the like using characters, images, sounds, and the like according to execution of a program in the system control unit 50. The display unit 54 is installed at a single or a plurality of positions near the operation unit of the imaging apparatus 100 so as to be easily visible, and is configured by a combination of, for example, an LCD, an LED, and a sounding element. Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM or a flash memory.

  Reference numeral 60 denotes a power switch (main switch) that can switch the power of the imaging apparatus 100 on and off. In addition, the power ON / OFF setting of various accessory devices connected to the imaging device 100 can be switched together.

  Reference numeral 62 denotes a shutter switch SW1, which is turned ON during the operation of a shutter button (not shown), and issues an instruction to start shooting preparation processing such as AF processing, AE processing, AWB processing, and EF processing for still image shooting. That is, a preparation instruction for still image shooting is performed to shift the state of the imaging apparatus 100 to a shooting preparation state in which shooting preparation processing is performed.

  Reference numeral 64 denotes a shutter switch SW2, which is turned on when an operation of a shutter button (not shown) is completed, and issues a start instruction for a series of photographing processes. That is, a shooting instruction for still image shooting is issued. A series of photographing processes is an exposure process in which a signal read from the image sensor 14 is written into the memory 30 via the A / D converter 16 and the memory control circuit 22, and the image processing unit 20 and the memory control circuit 22 This is processing such as development processing using computation.

  An operation unit 70 includes various buttons and a touch panel, and includes a menu button, a set button, a menu movement + (plus) button, a menu movement− (minus) button, an image display ON / OFF button, and the like.

  Reference numeral 72 denotes a mode dial switch which can switch and set each function mode such as a still image recording mode, a moving image recording mode, and a reproduction mode. Reference numeral 75 denotes an attitude detection sensor, which can detect whether the attitude of the imaging apparatus 100 is the vertical position or the horizontal position.

  Reference numeral 80 denotes a power control means, which includes a battery detection circuit, a DC-DC converter, a switch circuit for switching a block to be energized, and the like, and detects whether or not a battery is installed, the type of battery, and the remaining battery level. Then, the DC-DC converter is controlled based on the detection result and the instruction of the system control unit 50, and a necessary voltage is supplied to each unit including the recording medium for a necessary period. Reference numerals 82 and 84 denote connectors, and reference numeral 86 denotes a power source means such as a battery or an AC adapter.

  Reference numeral 90 denotes an interface with a recording medium such as a memory card or hard disk, and reference numeral 92 denotes a connector for connecting to a recording medium such as a memory card or hard disk.

  Reference numeral 102 denotes protection means that is a barrier that prevents the imaging unit from being soiled or damaged by covering the imaging unit including the photographing lens 10 of the imaging device 100.

  Reference numeral 104 denotes an optical viewfinder, which can take an image using only the optical viewfinder without using the electronic viewfinder function of the image display unit 28.

  Reference numeral 200 denotes a recording medium such as a memory card or a hard disk. The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, and the like, an interface 204 with the imaging device 100, and a connector 206 that connects to the imaging device 100. Note that the recording medium 200 is built in the imaging apparatus 100 in this embodiment.

  FIG. 2 is a flowchart for explaining the overall operation of the imaging apparatus 100 according to the present embodiment.

  When the power switch 60 is operated and the power is switched on, the system control unit 50 initializes flags, control variables, and the like in step S201. Subsequently, in step S202, management processing relating to the file recorded on the recording medium 200 is started.

  Next, in steps S203, S205, and S207, the system control unit 50 determines the setting position of the mode dial switch 72. If the still image recording mode is set, the process proceeds to step S204 to execute still image recording mode processing. Details of the still image recording mode processing in step S204 will be described later with reference to FIG. If the mode dial switch 72 is set to the moving image recording mode, the process proceeds to step S206, and the moving image recording mode process is executed. If the mode dial switch 72 is set to the playback mode, the process proceeds to step S208 to execute playback mode processing.

  If another mode has been set, the process proceeds to step S209, and the system control unit 50 executes a process according to the selected mode. Other modes include, for example, a transmission mode for transmitting a file stored in the recording medium 200 to an external device via a communication unit (not shown), and reception for receiving a file from the external device and storing it in the recording medium 200. Mode is included.

  After executing the process corresponding to the mode set by the mode dial switch 72 in steps S204, S206, S208, and S209, the process proceeds to step S210. In step S <b> 210, the system control unit 50 determines the set position of the power switch 60. If the power switch 60 is set to ON, the process returns to step S203. On the other hand, if the power switch 60 is set to power OFF, the process proceeds to step S211 and the system control unit 50 performs an end process. The termination process includes, for example, the following process. That is, the display of the image display unit 28 is changed to an end state, the lens barrier 102 is closed to protect the imaging unit, parameters, setting values, and setting modes including flags and control variables are recorded in the nonvolatile memory 56, Shut off the power to parts that do not require power supply. When the termination process in step S211 is completed, the present process is terminated and the power is turned off.

  The still image recording mode process in step S204 of FIG. 2 will be described using the flowcharts shown in FIGS. The still image recording mode process described below is terminated by an interrupt process or the like when the mode dial switch 72 switches to another mode or when the power switch 60 is set to OFF. To do. In the following, AE control (second exposure control mode, hereinafter referred to as servo AE) in which an exposure control value is changed in accordance with a change in subject brightness when the shutter switch SW1 is ON (while SW1 is being held). The still image recording mode process will be described as being executable. During the servo AE, as will be described later, when the acquired photometric value changes, at least one of the aperture value and the exposure time is changed according to the change amount. The exposure response range is limited. Note that the aperture (Av), the exposure time (Tv), the ND filter, the sensitivity (gain), and the like can be considered as elements constituting the exposure control value, but for the sake of simplicity, the aperture (Av) and the exposure time (Tv) will be described below. ) Only as an exposure control value.

  When starting the still image recording mode, the system control unit 50 determines the shooting mode in step S301. The shooting mode is determined by obtaining the shooting mode at the end of the previous still image recording mode from the nonvolatile memory 56 and storing it in the memory 52. Alternatively, when the operation unit 70 is operated by the user and the setting of the shooting mode is input, the setting and input shooting mode is stored in the memory 52. Note that the shooting mode in the still image recording mode can be arbitrarily selected from a plurality of shooting modes by operating the operation unit 70. Selectable shooting modes include an auto mode that is automatically determined by a program incorporated in the imaging apparatus 100 based on photometric values obtained by measuring various camera parameters, and various camera parameters can be freely set by the user. Manual mode. In addition, a scene mode in which setting of exposure conditions suitable for the shooting scene is automatically determined is included.

  In step S <b> 302, when the shooting mode is determined in step S <b> 301, the system control unit 50 subsequently performs a through display in which image data from the imaging unit is displayed on the image display unit 28.

  Subsequently, in step S <b> 303, the system control unit 50 determines whether there is a problem in the operation of the imaging apparatus 100 with the remaining capacity constituted by a battery or the like using the power supply control unit 80, the presence / absence of the recording medium 200, and the remaining capacity. Determine whether. If there is a problem such as a shortage of remaining battery capacity, a predetermined warning is displayed by image or sound using the image display unit 28 in step S304, and the process returns to step S301.

  If it is determined in step S303 that there is no problem, photometric processing is performed in step S305. In step S <b> 305, the system control unit 50 obtains a photometric value indicating the subject luminance based on the signal level of the image data read from the imaging unit, and stores it in the memory 52. The metering process reflects a metering method that can be set using the operation unit 70. The metering method includes spot metering in which only the spot metering frame displayed on the image display unit 28 is a metering area, center-weighted metering in which the entire area of the screen is a metering area and weights in the center, and substantially the entire screen. Evaluative metering that corrects photometric data based on the luminance distribution and the like. As for the evaluation photometry, when the face of the subject is detected by the image processing unit 20, the detected face area is weighted to perform exposure control.

  In step S306, exposure control is performed according to the photometric result in step S305. Here, the aperture is also changed according to the photometric value. Further, for a dark subject, control is performed such that the settable exposure time is extended by setting the imaging rate (frame rate) low, and a long exposure time is set. That is, an exposure response range (hereinafter referred to as follow-up) that is provided in the range of photometric values that can be acquired and changes at least one of the aperture value and the exposure time according to the amount of change when the acquired photometric value changes. The exposure control (first exposure control mode) is performed in the normal range.

  Next, in step S307, the system control unit 50 determines whether the shutter switch SW1 is ON. If the shutter switch SW1 is OFF, the process returns to step S305, and steps S305 and S306 are repeated. On the other hand, if the shutter switch SW1 is ON, the process proceeds to step S308.

  In step S308, in order to obtain the latest photometric value when the shutter switch SW1 is turned on, the first photometric process is performed after the shutter switch SW1 is turned on, and the photometric value is stored in the memory 52.

  Next, based on the photometric value stored in step S308, the system control unit 50 performs exposure control suitable for AF processing (step S309). For example, control is performed to open the aperture so that AF processing can be performed in a state where the depth of field is shallow. At this point, since exposure control is performed without providing a limit of the tracking range as will be described later, the aperture may be opened until the aperture value reaches the most open side. After the exposure control is completed, AF processing is performed in step S310 to focus the photographing lens 10 on the subject, and the process proceeds to step S311.

  In step S311, an exposure control value for still image shooting is calculated based on the photometric value stored in step S308. For example, an exposure control value suitable for the shooting scene is obtained by using a program diagram corresponding to the shooting mode determined in S301. The obtained still image exposure control value is stored in the memory 52.

  In step S312, the non-servo AE SW1 exposure control value is calculated and stored in the memory 52. The non-servo AE SW1 exposure control value is an exposure control value during SW1 holding when the aperture value and exposure time are fixed without being changed even if the subject brightness changes during SW1 holding. Here, in order to suppress the time lag due to the aperture driving at the time of shooting (when SW2 is ON), the aperture value of the SW1 exposure control value for non-servo AE is matched with the aperture value for the still image obtained in step S311.

  In step S313, the system control unit 50 determines whether to perform flash photography. For example, with reference to the still image exposure control value stored in step S311, it is determined to perform flash photography when the exposure time is longer than a predetermined value or when it is determined that the scene is a backlight scene from the imaging data. The determination result is stored in the memory 52.

  In step S401 shown in FIG. 4, the system control unit 50 performs a servo AE determination process for determining whether to perform servo AE. Step S401 for performing the servo AE determination process will be described later with reference to FIG.

  If it is determined that servo AE is to be performed based on the determination result in step S401 (step S402), the process proceeds to step S403, and servo AE information storage processing is performed. This servo AE information storage process will be described later with reference to FIG.

  In step S404, a servo AE SW1 exposure calculation process is performed. This servo AE SW1 exposure calculation process will be described later with reference to FIG.

  Next, the system control unit 50 determines whether or not the subject is properly exposed based on the servo AE SW1 exposure control value obtained in step S404 (step S405). If it is determined that it is not appropriate, the process proceeds to step S406. As will be described later, in step S404, the exposure time of the servo AE SW1 exposure control value is limited to a range in which the imaging rate does not decrease. In this case, the process proceeds to step S406.

  If it is determined in step S402 that the servo AE is not performed, or if it is determined in step S405 that the servo AE SW1 exposure control value is not appropriate, the process proceeds to step S406. In step S406, the system control unit 50 performs exposure control so that the non-servo AE SW1 exposure control value stored in step S312 is obtained. After that, if the shutter switch SW1 is turned on, the exposure control value is fixed until the shutter switch SW2 is turned on and photographing is performed. In step S407, the servo AE flag stored in the memory 52 is turned OFF.

  If it is determined in step S405 that the servo AE SW1 exposure control value is appropriate, the process proceeds to step S408. In step S408, the system control unit 50 performs exposure so that the servo AE SW1 exposure control value stored in step S404 is obtained. Take control. In step S409, the servo AE flag stored in the memory 52 is set.

  In step S501 shown in FIG. 5, the ON / OFF state of the shutter switch SW2 is determined. If the shutter switch SW2 is ON, the process proceeds to step S601 shown in FIG.

  If the shutter switch SW2 is OFF (step S501), and if the shutter switch SW1 is also OFF (step S502), the process returns to step S305. While the shutter switch SW1 is ON and the shutter switch SW2 is OFF, the processes in steps S501 and S502 are repeated.

  After setting the servo AE flag stored in the memory 52 in step S409, the system control unit 50 starts servo AF in step S503. Servo AF refers to AF control that keeps focusing by performing focus control following the movement of the subject while holding SW1, and thereafter focusing on the subject until servo AF is stopped. Perform a process to continue matching.

  Next, the system control unit 50 determines whether there is any change in the state of the dial or pop-up strobe included in the operation unit 70 (step S504). Here, the object for determining the state change is an operation member related to the setting that affects the exposure condition, such as an ISO dial capable of setting the ISO sensitivity, an exposure correction dial capable of setting the exposure correction value, a pop-up strobe, and the like. . If there is a change in these states, the process returns to step S311.

  If there is no change in the dial or pop-up state (S504), photometric processing is performed to obtain the latest photometric value, and the photometric value is stored in the memory 52 (S505).

  In step S506, the system control unit 50 calculates a servo AE still image exposure control value for the photometric value obtained in step S505. This servo AE still image exposure calculation process will be described later with reference to FIG.

  Next, in step S507, the system control unit 50 calculates the SW1 exposure control value for servo AE for the photometric value obtained in step S505. This servo AE SW1 exposure calculation process will be described later with reference to FIG.

  In step S508, exposure control is performed so that the servo AE SW1 exposure control value obtained in step S507 is obtained.

  In step S509, the display on the display unit 54 is updated according to the exposure control value calculated in step S506. For example, the aperture value, exposure time, and ISO sensitivity obtained in step S506 are displayed, and a camera shake warning is displayed according to the exposure time. Normally, when the exposure time is long, a strobe warning may be issued together with a camera shake warning display. However, the strobe warning is not performed here. This is because during the servo AE, the exposure time may change, and if the strobe state is matched with that, the light emission / non-light emission may be frequently switched. If the light emission / non-light emission is switched, even if a sudden light emission is attempted, a charging completion wait occurs and the release time lag is increased, so that the flash is not emitted even during the exposure time of the servo AE. That is, whether or not flash shooting is to be performed is determined at the timing of step S313 before the servo AE is started, and during the servo AE, whether or not flash shooting is to be performed is not determined even if the subject brightness changes. Like that.

  In steps S510 and S511, it is determined whether the shutter switch SW1 and the shutter switch SW2 are on or off. If the shutter switch SW2 is ON (step S510), the servo AF is stopped (step S512), and the process proceeds to step S601.

  If the shutter switch SW2 is OFF (step S510) and the shutter switch SW1 is also OFF (step S511), the servo AF is stopped (step S513), and the process returns to step S305. While the shutter switch SW1 is ON and the shutter switch SW2 is OFF, steps S504 to S511 are repeated.

  In step S601 illustrated in FIG. 6, the system control unit 50 interrupts the through display of the image display unit 28. In step S602, the system control unit 50 executes photographing processing including exposure processing and development processing. In the exposure process, image data photographed in the memory 30 via the A / D conversion unit 16, the image processing unit 20, the memory control circuit 22, or directly from the A / D conversion unit 16 via the memory control circuit 22. Is written. In the development process, the system control unit 50 reads the image data written in the memory 30 as necessary and performs various processes. Details of this photographing process will be described later with reference to FIG.

  Next, in step S603, the system control unit 50 causes the image display unit 28 to display a REC review display of the image data obtained by the shooting process. Rec review is a process of displaying image data on the image display unit 28 for a predetermined time (review time) after photographing and before recording on a recording medium for confirmation of the photographed image. After the REC review display, in step S604, the system control unit 50 executes a recording process for writing the image data obtained by the photographing process to the recording medium 200 as an image file.

  When the recording process in step S604 ends, in step S605, the system control unit 50 determines the ON / OFF state of the shutter switch SW2. If the shutter switch SW2 is ON, the determination in step S605 is repeated, and the process waits for the shutter switch SW2 to be OFF. During this time, the display of the REC review on the image display unit 28 is continued. With this configuration, the user can carefully check the captured image data using the REC review by continuing to fully press the shutter button.

  After the user has taken a picture with the shutter button fully pressed, when the shutter button SW2 is turned off by releasing the shutter button and the shutter switch SW2 is turned off, the process proceeds to step S606. In step S606, the system control unit 50 determines whether or not a predetermined predetermined review time has elapsed. If the predetermined review time has elapsed, the system control unit 50 proceeds to step S607. In step S607, the system control unit 50 returns the display state of the image display unit 28 from the REC review display state to the through display state. With this processing, after the captured image data is confirmed by the REC review display, the display state of the image display unit 28 is automatically switched to a through display state in which image data from the imaging unit is sequentially displayed for the next shooting. Become.

  In step S608, the system control unit 50 determines whether the shutter switch SW1 is ON / OFF. If the shutter switch SW1 is ON, the system control unit 50 proceeds to step S609. If it is OFF, the system control unit 50 returns to step S305.

  In step S609, the servo AE flag stored in the memory 52 is referred to. If the flag is ON, the process returns to step S503. If the flag is OFF, the process returns to step S501. That is, when the shutter button is half-pressed (shutter switch SW1 is ON), the system control unit 50 prepares for the next shooting (steps S501 and S503). On the other hand, if the half-pressed state of the shutter button is released (shutter switch SW1 is OFF), the system control unit 50 ends the series of shooting operations and returns to the shooting standby state (step S305).

  FIG. 7 is a flowchart showing the servo AE determination process in step S401 shown in FIG. FIG. 7 shows an example of the determination items, and the determination is not necessarily performed based on the items shown in FIG. Further, the timing of performing the determination process may not be the timing of step S401 as long as the state of the determination item being held in SW1 is confirmed.

  The system control unit 50 refers to the shooting mode stored in the memory 52 in step S301, and determines whether or not the shooting mode is for performing the AE process (step S701). If the shooting mode does not perform AE processing, the process proceeds to step S705, and servo AE is not executed while SW1 is held. An example of the shooting mode in which the AE process is not performed is a manual mode.

  If the shooting mode is to perform the AE process (step S701), the system control unit 50 determines the ON / OFF setting state of the servo AF (step S702). If the servo AF is set to OFF, the process proceeds to step S705, and the servo AE is not executed.

  If the servo AF is set to ON (step S702), the system control unit 50 refers to the result of the light emission determination in step S313, and if it is determined to perform flash shooting, the process proceeds to step S705.

  If it is determined not to perform flash photography (step S703), the system control unit 50 determines whether or not the AE is locked (step S704). If the AE is locked, the process proceeds to step S705. The AE lock can be executed by operating an AE lock button included in the operation unit 70.

  If the AE is not locked (step S704), the system control unit 50 stores the determination result in the memory 52 as executing the servo AE (step S706), and ends the servo AE determination process.

  In step S705, the system control unit 50 stores the determination result in the memory 52 on the assumption that the servo AE is not executed, and ends the servo AE determination process.

  FIG. 8 is a flowchart showing the servo AE information storage process in step S403 of FIG.

  In step S801, the system control unit 50 determines whether or not the first information storage process after the shutter switch SW1 is turned on. If the information storage process to be described later has already been performed once, such as when the exposure correction dial included in the operation unit 70 is turned with the shutter switch SW1 turned on, the process proceeds to step S805.

  If it is the first information storage after the shutter switch SW1 is turned on, the process proceeds to step S802, and the latest photometric value is stored in the memory 52. The photometric value stored here is the value obtained in step S308. Note that the recorded photometric value does not have to be the value obtained in step S308. If the value obtained in step S308 and the value obtained in step S305 are substantially equal, the value obtained in step S305 is stored. May be.

  Next, in step S803, a tracking range in which exposure control is performed in accordance with the change in subject brightness while SW1 is held is set and stored in the memory 52. For example, the tracking range is set so that exposure control is performed by changing at least one of the aperture value and the exposure time when the photometric value changes in a range of ± 2 steps centering on the photometric value stored in step S802. . The follow-up range set here is related to the exposure control value used during photometry while holding SW1, so that the exposure correction value is not reflected even when the exposure correction value is set to obtain photometric accuracy. In addition, the range of ± 2 steps centered on the photometric value is set as the tracking range, but a predetermined range based on the photometric value may be set as the tracking range, and is limited to the range of ± 2 steps centering on the photometric value. It is not something. For example, a range where the photometric value is not the center, such as a range of +1 step and −2 step with reference to the photometric value, may be set as the tracking range. Or you may enable it to operate and set the operation part 70 as an arbitrary range judged from the photometry result etc. by the user.

  Further, in step S804, the latest face detection number is stored in the memory 52, and the process proceeds to step S805. Depending on the number of faces stored in step S804, whether or not to perform AE processing with emphasis on the face area detected while holding SW1 is switched. For example, when the number of detected faces stored in step S804 is 0, the entire photometry area is always set as the photometric area while holding SW1, and it is detected even if a new face is detected while holding SW1. Avoid exposure control with emphasis on the face area. Conversely, when the number of detected faces stored in step S804 is 1 or more, exposure control is performed so that the detected face area is always properly exposed while SW1 is held. When a face is not detected while SW1 is held, the exposure control value is fixed in a state where the last detected face area is in a proper exposure. When the face is detected again, the exposure control is resumed so that the detected face area is properly exposed. In the case of the normal AE performed in step S306, the entire screen photometry is performed when no face is detected, and the face-weighted photometry is switched when the face is detected. Therefore, the normal AE and servo AE performed in step S306 are Different controls will be performed.

  In step S <b> 805, the system control unit 50 sets a still image tracking range that is a range in which the exposure control value for the still image is tracked with respect to a change in subject luminance by the servo AE, and stores the still image tracking range in the memory 52. For example, the tracking range is set so that exposure control is performed by changing at least one of the aperture value and the exposure time when the photometric value changes in a range of ± 2 steps centering on the photometric value stored in step S802. . The still image follow-up range set here is different from the follow-up range set in step S803 in that it is a value that reflects the exposure correction value set by the user. When the exposure correction value changes, the still image tracking range also changes. Therefore, when the exposure correction dial included in the operation unit 70 is operated while SW1 is held, the still image tracking range is reset. .

  When the still image tracking range is determined in step S805, an exposure control value corresponding to the still image tracking range lower limit is obtained using a program diagram or the like in step S806 and stored in the memory 52. The lower limit of the tracking range represents the tracking limit when the subject brightness is low (the subject is dark), and the upper limit of the tracking range is the tracking limit when the subject brightness is high (the subject is bright). It shall be expressed. Here, a still image exposure control value is obtained using a program diagram that opens the aperture most for the same luminance, which will be described later with reference to FIG.

  Next, exposure control values corresponding to the upper limit and lower limit of the tracking range during SW1 holding are obtained and stored in the memory 52 (step S807). Regarding the exposure control value obtained here, the aperture value is matched with the still image aperture value obtained in step S806. When the process is finished, the servo AE information storage process is finished.

  FIG. 9 is a flowchart showing the servo AE still image exposure calculation processing in step S506 of FIG.

In step S <b> 901, the system control unit 50 performs clip processing on a target exposure value indicating a target exposure value for exposure control obtained from the latest photometric value based on the still image tracking range. That is, when the target exposure value is Ev and the exposure values corresponding to the lower and upper photometric values of the still image tracking range are Ev (a) and Ev (b) {Ev (a) <Ev (b)}, respectively. , Ev and Ev (a), Ev (b) are corrected as follows according to the magnitude relationship. The corrected target exposure value is Ev after correction.
After correction Ev = Ev (a) {Ev <Ev (a)}
After correction Ev = Ev {Ev (a) ≦ Ev ≦ Ev (b)}
After correction Ev = Ev (b) {Ev> Ev (b)}
As described above, if the target exposure value falls below the exposure value corresponding to the lower limit of the tracking range, the exposure value corresponding to the lower limit of the tracking range is corrected to become the target exposure value, and the exposure value corresponding to the upper limit of the tracking range is changed. If it exceeds, the exposure value corresponding to the upper limit of the tracking range is corrected to become the target exposure value. Note that the photometric value used here is obtained in step S505. Further, the exposure correction value set by the user is reflected on the target exposure value Ev. That is, when the exposure correction value is not set, the exposure value at which the appropriate exposure is obtained is set as the target exposure value. However, when the exposure correction value is set, the exposure correction value is more than the exposure value at which the appropriate exposure is obtained. The shifted exposure value is set as a target exposure value Ev.

  Next, in step S902, an exposure control value for realizing the corrected Ev, which is the corrected target exposure value obtained in step S901, is determined using a program diagram or the like, stored in the memory 52, and servo AE stationary. Step S506 for performing the image exposure calculation process is terminated.

  FIG. 10 is a flowchart showing the servo AE SW1 exposure calculation processing in step S404 of FIG. 4 and step S507 of FIG.

In step S <b> 1001, the system control unit 50 performs clip processing on the target exposure value indicating the exposure value that is the target of exposure control obtained from the latest photometric value within the tracking range that is held by SW <b> 1. That is, the target exposure value is Ev ′, and the exposure values corresponding to the lower limit and upper limit photometric values of the tracking range during SW1 holding are Ev (a) ′, Ev (b) ′ {Ev (a) ′ <Ev (b, respectively. ) ′}, The target exposure value is corrected as follows in the same manner as in S901. The corrected target exposure value is set to Ev ′ after correction.
After correction Ev ′ = Ev (a) ′ {Ev ′ <Ev (a) ′}
After correction Ev ′ = Ev ′ {Ev (a) ′ ≦ Ev ′ ≦ Ev (b) ′}
After correction Ev ′ = Ev (b) ′ {Ev ′> Ev (b) ′}
As described above, if the target exposure value falls below the exposure value corresponding to the lower limit of the tracking range, the exposure value corresponding to the lower limit of the tracking range is corrected to become the target exposure value, and the exposure value corresponding to the upper limit of the tracking range is changed. If it exceeds, the exposure value corresponding to the upper limit of the tracking range is corrected to become the target exposure value. The target exposure value Ev ′ does not take into account the exposure correction value set by the user, and an exposure value that always provides proper exposure is set as the target exposure value Ev ′.

  In step S1002, the aperture value and ND filter are matched with the aperture value and ND filter stored in step S806. Further, the exposure time is determined in accordance with the corrected Ev ′ that is the corrected target exposure value obtained in step S1001 within a range where the imaging rate is not lowered (step S1003). By limiting the exposure time to a range in which the imaging rate does not decrease, image blur caused by a long exposure time can be prevented and servo AF can be performed with high accuracy. In this embodiment, the exposure control is performed during the servo AE with an exposure time in a range that does not lower the imaging rate. However, particularly when the imaging rate is low, the longest exposure time that is allowable from the viewpoint of AF accuracy. May be set so that the exposure time does not increase beyond that. In other words, during the servo AE, the longest exposure time that can be set may be controlled to be shorter than the normal exposure control.

  Finally, in step S1004, the exposure is determined by adjusting the sensitivity so as to realize the corrected target exposure value Ev ′, and the steps S404 and S507 for performing the servo AE SW1 exposure calculation process are ended.

  FIG. 11 is a flowchart showing the photographing process in step S602 of FIG.

  In step S <b> 1101, the system control unit 50 acquires the date and time from a system timer (not shown) at the start of shooting and stores it in the memory 52. Subsequently, in step S1102, the shutter 12 having an aperture function is controlled in accordance with the aperture value stored in step S311 or S506. If a separate ND filter is provided, the ND is also controlled here. Thus, exposure is started (step S1103).

  In step S1104, the system control unit 50 waits for the exposure of the image sensor 14 to end according to the exposure time stored in step S311 or S506. When the exposure end time is reached, the system control unit 50 closes the shutter 12 in step S1105. In step S 1106, the charge signal is read from the image sensor 14 and passed through the A / D converter 16, the image processor 20, the memory control circuit 22, or directly from the A / D converter 16 through the memory control circuit 22. The image data is written into the memory 30. At this time, processing for amplifying the signal at the time of reading is also performed according to the sensitivity setting. As described above, steps S1101 to S1106 correspond to the exposure process.

  Subsequently, in step S1107, the system control unit 50 reads out the image data written in the memory 30 and sequentially performs image processing as necessary. This image processing includes, for example, white balance processing, compression processing using the compression / decompression unit 32, and the like. Further, dark part correction processing for gaining up a dark part of the image data is also performed here. The processed image data is written into the memory 30. In step S 1108, the system control unit 50 reads the image data from the memory 30, expands the image data using the compression / expansion unit 32, and resizes the image data for display on the image display unit 28. Then, the resized image data is transferred to the D / A converter 26 for display on the image display unit 28. When a series of processing is finished, the photographing processing is finished.

  Next, the process for obtaining the still image exposure control value in step S806 will be described with reference to FIG. FIG. 12 shows an example of a program diagram for still images, FIG. 12A shows an example of a normal program diagram, and FIG. 12B shows a program diagram when motion of a subject is detected. An example is shown.

  A relationship between the still image exposure control value and the tracking range will be described with reference to FIG. First, it is assumed that the appropriate exposure value of the still image corresponding to the photometric value at the time when the shutter switch SW1 is turned on is Ev1. The photometric value at this time is the one stored in step S802. As the still image tracking range when performing servo AE, for example, from a photometric value that is one step lower than the photometric value corresponding to the appropriate exposure value Ev1 to a photometric value that is one step higher than the photometric value corresponding to the appropriate exposure value Ev1. Set the range as the tracking range. That is, as the follow-up range of the exposure value, the range of the appropriate exposure value Ev1 ± 2 steps is the follow-up range. This process corresponds to the process in step S805.

  Once the still image tracking range has been set, processing for obtaining a still image exposure control value at the lower limit of the tracking range, which is processing in step S806, is performed. In the example shown in FIG. 12A, the still image exposure control value at the lower limit of the tracking range is obtained as (Av1, Tv1). When exposure control is performed while following the subject within the tracking range during servo AE, the exposure control value that most likely opens the aperture is (Av1, Tv1). For this reason, if the aperture value is opened to Av1 while holding SW1, the aperture is not opened with a still image compared to the aperture when the servo AF is operated and focusing is performed while SW1 is held. That is, it is possible to prevent the focus from deviating by opening the aperture and reducing the depth of field. In view of this, in this embodiment, Av1, which is the minimum aperture value in the aperture value corresponding to the tracking range, is stored as the aperture value used for exposure control while holding SW1, and the servo AE SW1 in steps 404 and 507 is stored. The reference is made in the exposure calculation process.

  When the subject becomes bright from the time when SW1 is turned on, the exposure control value for actual still image shooting calculated in step S506 is, for example, (Av2, Tv2). In this case, the aperture is fixed so that the aperture value becomes Av1 while holding SW1 at the timing of steps S408 and S508, and the aperture value is set to Av2 at the timing of step S1102, that is, at the time of still image exposure control. Squeeze to become.

  As described above, since Av2 is in a state in which the aperture is reduced from Av1, the depth of field changes from a shallow state to a deep state even if the aperture value is changed during still image exposure control. While SW1 is held, a still image can be photographed while the subject is in focus.

  In addition, by limiting the tracking range for changing the aperture value and exposure time during servo AE, and fixing the aperture at the minimum aperture value among the aperture values corresponding to the tracking range until an instruction to start shooting processing is given, It is possible to limit the amount of change in the aperture when changing the aperture value during still image exposure control. By doing so, the release time lag associated with aperture control can be reduced.

  Also, by setting the tracking range based on the photometric value at the time when SW1 is turned on, it is possible to set the tracking range corresponding to the amount of change in the subject brightness assumed during SW1 holding. Therefore, it is possible to reduce the influence of the problem that smearing occurs and the photometric accuracy is lowered by opening the aperture without opening the aperture more than necessary to fix the originally bright subject. In addition, when the aperture is opened, photometry is performed in a region where the linearity of input / output of the image sensor is broken, so that it is possible to reduce the influence of the problem that the photometry accuracy is lowered and the high luminance followability is lowered.

  Next, in addition to the normal program diagram shown in FIG. 12A, for example, a still image exposure control value in the case of having a plurality of program diagrams, such as a program diagram when motion of a subject is detected. The processing for obtaining will be described with reference to FIG. For comparison, in FIG. 12B, the program diagram when the subject is stationary (the normal program diagram shown in FIG. 12A) is also shown by broken lines.

  Examples of the method for detecting the movement of the subject include the following methods. A method in which the image processing unit 20 detects a difference between frames of image data continuously captured and detects the difference based on the magnitude of the difference, a method in which the system control unit 50 monitors a photometric result and detects it by a change in a photometric value, and the like. Can be mentioned. In addition, a method in which the system control unit 50 monitors face position information detected by the image processing unit 20 and detects it based on the amount of movement of the face (positional difference), based on an output signal of a gyro unit (not shown). Although the method of detecting etc. is mentioned, you may detect a subject's movement by any method.

  When the subject is moving, it is desired that the exposure time be as short as possible to prevent subject blurring, so that there is a tendency to open the aperture for subjects with the same luminance. For example, with respect to the exposure value Ev1-2 corresponding to the lower limit of the tracking range, the aperture value is Av1 = 4 in the program diagram when the subject is stationary, but Av3 = 3 in the program diagram when the motion is detected. The aperture is opened (exposure time is further shortened). When the exposure control is performed by appropriately switching between the two diagrams according to the result of the motion detection of the subject during the servo AE, the exposure during SW1 holding is performed using the program diagram at the time of motion detection that opens the aperture more. It is desirable to obtain the aperture value used for control. For example, assuming that the subject is stationary at the time of SW1, the still image exposure control value at the lower limit of the tracking range is obtained as (Av1, Tv1) using the program diagram when the subject is stationary, and the aperture value is set to Av1 while SW1 is held. And exposure control. At this time, if the subject moves just before shooting (SW2) and the system control unit 50 detects the movement and switches the program diagram, the exposure value corresponding to the photometric value is finally Ev1-2. Photographing is performed with an exposure control value of (Av3, Tv3). When the aperture control is performed in this way, Av1> Av3. Therefore, even if the subject is focused by servo AF while SW1 is held, the aperture is opened during still image shooting, and the subject is in focus. There is a possibility that still images will not be taken. In order to prevent this, in step S806, a still image exposure control value at the lower limit of the tracking range and SW1 holding are used using a program diagram that opens the aperture most for the same subject luminance, such as a program diagram at the time of motion detection. The aperture value in the middle is calculated. In this way, even if the program diagram to be used is switched, the aperture is not opened at the time of still image shooting, and it is possible to prevent the focus from deviating with respect to the subject focused on while holding SW1.

  In the present embodiment, only the case where the program diagram is switched in accordance with the motion detection of the subject has been described. However, the program diagram is not limited to the motion detection, and the program diagram is switched according to the shooting conditions during the servo AE. In such a case, the same processing may be performed. For example, the same applies to the case where the characteristics of the shooting scene are extracted and determined by the image processing unit 20 and the system control unit 50, and the program diagram is automatically switched to a program diagram suitable for the shooting scene.

  Next, the difference between the still image tracking range during servo AE and the tracking range during SW1 holding will be described with reference to FIG. FIG. 13 is an example of a program diagram for obtaining a still image exposure control value and an exposure control value while holding SW1. Note that Ev1, Ev2, (Av1, Tv1), (Av2, Tv2), and (Av3, Tv3) used in FIG. 13 are also used in FIG.

  FIG. 13A is a program diagram for still image exposure. When the appropriate exposure value corresponding to the photometric value when the shutter switch SW1 is turned ON is Ev1, and the range of the appropriate exposure value Ev1 ± 1 step is set as the tracking range (tracking range 1) as the tracking range of the exposure value think of. The exposure correction value set at this time is 0.

  If the servo AE is started in this state and the exposure correction value is changed to +3 in S504, for example, the follow-up range changes to an Ev2 ± 1 step range (Ev2 = Ev1-3) (follow-up range 2). Even if there is no change in the subject brightness, if the exposure correction value is changed to +3, it is necessary to shoot with an exposure control value that is three steps brighter. In other words, since it is necessary to open the aperture and photograph with a longer exposure time, the tracking range is shifted by the exposure correction value so that the range of the exposure value to be tracked is also shifted from the tracking range 1 to the tracking range 2. Similarly, when the exposure correction value is changed to −3, the follow-up range changes to a range of Ev3 ± 1 step (Ev3 = Ev1 + 3) (follow-up range 3).

  On the other hand, FIG. 13B shows the exposure control value during SW1 holding during servo AE in a program diagram. From FIG. 13A, the aperture value for the lower limit of the tracking range for still images when the exposure correction value is 0 is Av1, and the aperture value for the lower limit of the tracking range for still image exposure is Av2 when the exposure correction value is +3. The aperture value at the lower limit of the tracking range for still image exposure of −3 is Av3. Therefore, the SW1 exposure control value is fixed to Av = Av1 when the exposure correction value is 0, Av = Av2 when the exposure correction value is +3, and Av = Av3 when the exposure correction value is −3. Fixed.

  The tracking range during SW1 holding is different from the still image tracking range in that it is constant regardless of the exposure correction value. During the servo AE, since the photometric process is performed with the exposure control value held by SW1, the exposure control value held by SW1 is required to be suitable for photometry. When photometry is performed with an exposure control value that is not suitable for subject brightness, photometry is likely to occur in an area where the linearity of the input / output of the image sensor is broken, and the photometric accuracy is reduced. Therefore, since it is desirable to set an exposure control value suitable for the subject brightness in order to obtain photometric accuracy, the exposure control value during SW1 holding during servo AE is an appropriate exposure value regardless of the presence or absence of the exposure correction value. Set the exposure control value corresponding to. That is, the target exposure value in step S1001 is set to a value that does not reflect the exposure correction value. Further, the image data displayed on the image display unit 28 while holding SW1 is also displayed with the image data obtained with the exposure control value while holding SW1, so that the appropriate exposure that does not reflect the exposure correction is displayed. The image data will be displayed.

  As described above, since the exposure correction value is not reflected in the exposure control value while SW1 is held, the tracking range while SW1 is held is constant as shown in FIG. 13B even if the exposure correction value changes. However, since the aperture value varies depending on the exposure correction value, the combination of exposure control values varies depending on the exposure correction value.

  In view of these, the still image tracking range affected by the change of the exposure correction value and the still image aperture value corresponding to the lower limit of the tracking range are changed each time in step S404. On the other hand, information that does not change after SW1 is turned on, such as the follow-up range in which SW1 is held, is stored only in the first time in S403.

  As described above, even if the subject becomes dark after starting the still image recording preparation process (after SW1 is turned on), it corresponds to the subject brightness when the preparation process is started as long as it is within the tracking range. Shooting with a wider aperture than the aperture value is possible, and still images can be shot with a desired exposure.

  Since the aperture is fixed at the lower limit of the tracking range while SW1 is held, the aperture is not opened in still image shooting as compared with the state in which the focus is held while SW1 is held by servo AF. It is possible to avoid defocus due to the shallowness of the image.

  Further, during SW1 holding, the exposure time is controlled within a range that does not become longer than the predetermined time, thereby preventing image blur caused by the long exposure time and performing AE control without impairing the focusing accuracy of servo AF. Can do. In particular, the exposure time is controlled within a range where the imaging rate is not lowered, and the AE control can be performed without interfering with the AF control by keeping the imaging rate constant, so that the subject followability of the focus and the exposure is improved.

(Other examples)
The present invention can also be realized by executing the following processing. That is, software (program) for realizing the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

DESCRIPTION OF SYMBOLS 10 Shooting lens 12 Shutter 14 Image pick-up element 18 Timing generation circuit 20 Image processing part 28 Image display part 40 Exposure control means 42 Focus control means 50 System control part 52 Memory 62 Shutter switch SW1
64 Shutter switch SW2
70 Operation Unit 72 Mode Dial Switch 100 Imaging Device

Claims (5)

Imaging means for capturing an image of a subject and acquiring image data;
Photometric means for obtaining a photometric value based on image data obtained by the imaging means;
A first exposure control mode; and a second exposure control mode in which the longest exposure time that can be set is shorter than that of the first exposure control mode. The first exposure control mode and the second exposure control mode Exposure control means for performing exposure control based on a photometric value acquired by the photometry means in any one of the exposure control modes,
The imaging apparatus according to claim 1, wherein the exposure control unit performs exposure control by switching an exposure control mode from the first exposure control mode to the second exposure control mode when in a shooting preparation state.   The imaging apparatus according to claim 1, wherein the exposure control unit performs the exposure control with an exposure time in a range in which the frame rate is not reduced when performing the exposure control in the second exposure control mode. Preparation instruction means for instructing the state of the imaging apparatus to be in the shooting preparation state;
Determining means for determining whether to perform exposure control in the second exposure control mode;
The determination means determines that an instruction is given by the preparation instruction means,
The exposure control unit switches the exposure control mode from the first exposure control mode to the second exposure control mode when the determination unit determines that the exposure control is performed in the second exposure control mode. The imaging device according to claim 1, wherein: Focusing control means for performing focusing control based on image data acquired by the imaging means;
The determination unit determines that exposure control is performed in the second exposure control mode when the focus control by the focus control unit is performed in accordance with the movement of the subject in the shooting preparation state. The imaging device according to claim 3. An imaging apparatus control method comprising: an imaging unit that images a subject to acquire image data; and a photometric unit that acquires a photometric value based on the image data acquired by the imaging unit,
Based on a photometric value acquired by the photometric means in any one of the first exposure control mode and the second exposure control mode in which the longest exposure time that can be set is shorter than that of the first exposure control mode. Exposure control step for performing exposure control,
In the image pickup apparatus, the exposure control step performs exposure control by switching the exposure control mode from the first exposure control mode to the second exposure control mode when an instruction to start shooting preparation processing is given. Control method.

Images