JP2018098585A - Imaging apparatus, control method therefor, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an image having good exposure to be obtained even if aperture control is not performed in shooting of time lapse video.SOLUTION: An imaging apparatus includes an imaging section for acquiring an image by capturing a subject image, and executes intermittent imaging by using the imaging section, for acquiring a time lapse video by imaging the subject intermittently and connecting multiple images thus acquired, and further includes an aperture and an exposure control section for setting an aperture value of an aperture for use in intermittent imaging. The exposure control section maintains the aperture value, for use in the intermittent imaging, at a prescribed value during acquisition of the same time lapse video, on the basis of total imaging time for acquiring the same time lapse video.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for capturing a time-lapse moving image.

  2. Description of the Related Art Conventionally, a technique for acquiring a moving image (so-called time-lapse movie) in which a temporal change of a subject is compressed and recorded by sequentially joining a plurality of images acquired by intermittently capturing the subject is known. It has been.

  As one imaging method for acquiring this time-lapse moving image, Patent Document 1 discloses that a time-lapse moving image is generated by thinning out and compressing images from a series of moving images (interval shooting using image data for moving images). ) The technology has been proposed.

Japanese Patent Laying-Open No. 2015-142327

  However, since shooting for acquiring a time-lapse movie (time-lapse shooting) is a shooting in which a large number of frame images are acquired at a set shooting interval, in order to perform a movie-based interval shooting, the movie to be created An operation time more than several times the time is required. Therefore, if the operation of a mechanical part such as a diaphragm is controlled during photographing, the durability of the mechanism becomes a problem. For this reason, in time-lapse shooting, it is preferable to fix (maintain) the aperture so that it does not move during shooting. However, if the aperture is fixed at the start of time-lapse shooting, depending on the aperture value, exposure control for subsequent shooting may be greatly affected.

  For example, when time-lapse shooting is started at a bright time during the day and an attempt is made to obtain a moving image including a night view, the following problem occurs. In other words, the aperture is narrowed at the start of shooting because the surroundings are bright, but when shooting a night scene in that state, it is not possible to follow the exposure to the low-luminance side by the amount that is reduced. In this case, an image with appropriate brightness cannot be acquired for a subject included in a range where exposure tracking cannot be performed.

  This will be described more specifically with reference to FIG. FIG. 3 is a program diagram for shooting a normal moving image. This program diagram is a combination of controlling aperture (hereinafter referred to as Av), storage time (hereinafter referred to as Tv), and gain (hereinafter referred to as Sv) with respect to brightness (hereinafter referred to as Ev). It is a diagram used for deciding.

  In a normal moving image, it is preferable to make the depth of field as deep as possible (the aperture diameter of the aperture is narrowed down to the small aperture) so that the subject is in focus even if the subject moves slightly. For this reason, Av8 (F11) is used when it is brighter than Ev14, which is the general brightness of the daytime, and Av5 (F5.6) is used when it is brighter than Ev6, which is the general brightness of the room. I have to. When the brightness is lower than the general indoor brightness, the lens is set to an open aperture so that shooting can be performed with an appropriate exposure.

  When such a normal moving image program diagram is used to perform shooting such as day and night in time-lapse shooting, for example, the aperture value Av is fixed to the value at the start of daytime shooting. For example, under general daytime conditions at the start of shooting, Av8 is set as described above. In this case, Tv is limited to a value that can be set depending on the frame rate of the moving image. Therefore, even if Sv is used up to 13 (ISO25600), it is not possible to control the exposure until Ev6 is appropriate. Appropriate exposure cannot be set when shooting a night view of about Ev3. Conversely, when shooting is started at night, the aperture value of the aperture is set to the open side. Therefore, in a lens with an open aperture of Av2 (F2.0), the day is bright in that state. If it is attempted to shoot, it is possible to follow the exposure according to the luminance change of the subject only until Ev14.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to obtain an image with good exposure even when the aperture control is not performed during shooting in shooting a time-lapse movie.

  An imaging apparatus according to the present invention includes an imaging unit that captures a subject image to acquire an image, and in order to acquire a time-lapse movie in which a plurality of images acquired by intermittently capturing a subject are connected, An imaging apparatus that performs intermittent imaging using the imaging unit, and includes an aperture and an exposure control unit that sets an aperture value of the aperture, which is used for the intermittent imaging, and the exposure control The means maintains the aperture value used for intermittent imaging based on a total imaging time for acquiring the same time-lapse moving image at a predetermined value during acquisition of the same time-lapse moving image. .

  According to the present invention, it is possible to obtain a well-exposed image even when the aperture control is not performed during shooting in shooting a time-lapse movie.

1 is a block diagram showing a configuration of a digital camera that is an embodiment of an imaging apparatus of the present invention. 6 is a flowchart illustrating an operation of the imaging apparatus according to the embodiment. The figure which shows the program diagram 1 for exposure control. The figure which shows the program diagram 2 for exposure control. The figure which shows the program diagram 3 for exposure control. The figure which shows the exposure tracking range of each program diagram. The figure which shows the exposure tracking range of each program diagram. The figure which shows the exposure tracking range of each program diagram.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(Basic configuration of digital camera 1)
FIG. 1 is a block diagram showing a configuration of a digital camera (hereinafter simply referred to as a camera) 1 which is an embodiment of an imaging apparatus of the present invention. One or more of the functional blocks shown in FIG. 1 may be realized by hardware such as an ASIC or a programmable logic array (PLA), or may be realized by a programmable processor such as a CPU or MPU executing software. May be. Further, it may be realized by a combination of software and hardware. Therefore, in the following description, even when different functional blocks are described as the operation subject, the same hardware can be realized as the subject.

  As shown in FIG. 1, the camera 1 according to the present embodiment is a so-called interchangeable lens type imaging apparatus including a camera unit 100, an external recording medium 200, and a lens unit (imaging optical system) 300. It is not limited. For example, a configuration in which the camera unit 100 and the lens unit 300 are integrally provided may be employed, or a configuration without an optical finder 105 described later may be employed.

  First, the configuration of the camera unit 100 in the camera 1 will be described. In FIG. 1, a main mirror 101 guides a light beam corresponding to an optical image of a subject guided from a lens unit 300 (to be described later) into the camera unit 100 to the image sensor 103 side and the optical viewfinder 105 side. It is an optical member. The shutter 102 is a light shielding member for opening and shielding the optical path between the lens unit 300 and the image sensor 103. The image sensor 103 is a charge storage type solid-state image sensor such as a CCD or CMOS sensor, and generates an analog image signal by photoelectrically converting (imaging) a light beam of a subject incident through the lens unit 300.

  The pentaprism 104 is a second optical member that guides the light beam incident through the main mirror 101 to the optical viewfinder 105. The optical viewfinder 105 is a third optical member that allows the user to check the optical image of the subject. The A / D converter 106 converts the analog image signal output from the image sensor 103 into digital image data. The image processing circuit 107 performs various processing such as white balance adjustment processing and gradation processing on the digital image data output from the A / D conversion unit 106. The timing generation circuit 108 generates a signal (control signal such as a clock signal) for operating the image sensor 103, the A / D conversion unit 106, a D / A conversion unit 109 described later, and the like. The timing generation circuit 108 can control charge accumulation in the image sensor 103 by controlling the reset timing of the accumulated charge in the image sensor 103. The timing generation circuit 108 is controlled by a system control unit 120 described later.

  The memory control circuit 110 controls the A / D conversion unit 106, the image processing circuit 107, the D / A conversion unit 109, and the compression / decompression circuit 111, and writes the acquired image data to the image display memory 112 or the image recording memory 113. Execute the control. The image display unit 114 is a display unit that employs a TFT type LCD (thin film transistor driving type liquid crystal display), an organic EL element (organic electroluminescence element), or the like. The display digital image data written in the image display memory 112 is converted into a display analog image signal by the D / A conversion unit 109 and then displayed on the image display unit 114.

  The image recording memory 113 is a recording unit that stores image data acquired by capturing an image of a subject, and has a storage capacity sufficient to store a predetermined number of still image data and moving image data. The image recording memory 113 can also be used as a work area for the system control unit 120 described later. The compression / decompression circuit 111 reads the image data stored in the image recording memory 113, and compresses and decompresses the image data according to a predetermined image compression method and image decompression method in accordance with various uses. The shutter control circuit 115 is shutter control means for controlling the operation of the shutter 102, and controls the operation of the shutter 102 based on the subject photometric result calculated by the system control unit 120. The shutter 102 is controlled in conjunction with the control of a diaphragm 302 described later.

  The focus detection circuit 116 includes a focus sensor (not shown), and detects a focus state of an optical image (subject image) corresponding to a light beam incident from the lens unit 300 side via a sub mirror (not shown). It is. The photometric circuit 117 is a photometric unit that includes a photometric sensor (not shown) and calculates the brightness (luminance value) of an optical image corresponding to a light beam incident from the lens unit 300 side via a photometric lens (not shown). . Detection results of the focus detection circuit 116 and the photometry circuit 117 are input to the system control unit 120, and are used for lens position control (focus control) and exposure control of a focus lens (not shown) included in the lens unit 300.

  The system control unit 120 also performs lens position control (focus control) based on contrast information of image data captured by the image sensor 103 while shifting the position of the focus lens. Further, focus detection for detecting the in-focus state of the optical image from the captured image data can also be performed. Similarly, it is possible to perform photometry by calculating the luminance value of a subject using image data captured by the image sensor 103. Note that the imaging apparatus according to the present embodiment basically performs photometry and focus detection using image data captured by these imaging elements 103. The position detection circuit 118 detects the position of the camera 1 using a GPS (Global Positioning System) not shown.

  The system control unit 120 is a system control unit that comprehensively controls the operation of the camera 1, and is an exposure control unit that controls exposure based on the image data captured by the image sensor 103 as described above. It is also a focus control means. Further, as the above-described exposure control, parameters such as the aperture value related to the opening of the aperture 302, the charge accumulation time of the image sensor 103 corresponding to the shutter speed, and the imaging sensitivity related to analog and digital gain amounts are changed. A timer function using a system clock (not shown) is provided, and time information such as a shooting interval and a current time is managed from the time information set by the user by the operation unit 133. The main memory 121 stores in advance information related to exposure (appropriate exposure) with respect to the luminance value (program diagram based on table data or the like). The system control unit 120 can set an appropriate exposure according to the luminance value based on this information.

  Further, the system control unit 120 has a function of executing various controls relating to generation of a time-lapse moving image in a time-lapse mode to be described later. Details of various controls in the time lapse mode will be described later. The main memory 121 is a recording unit in which data related to the operation of the camera 1 is recorded. In the main memory 121, constants for operations executed by the camera 1, various exposure conditions, calculation formulas, and the like are stored in advance.

  The image synthesizing unit 122 generates a moving image (time-lapse moving image) in which temporal changes are compressed by connecting the image data acquired in the time lapse mode in the order in which the image data is captured. The nonvolatile memory 123 is a storage means that can be electrically erased and stored, such as an EEPROM typified by a flash memory.

  Each unit described below is an operation unit for inputting various operation instructions to the system control unit 120, and includes a button, a switch, a dial, a touch panel, a line-of-sight detection device, a voice recognition device, or a combination thereof. Consists of. The mode dial 130 is an operation member used when setting an arbitrary shooting mode from among a plurality of shooting modes that can be set by the camera unit 100. In the present embodiment, a plurality of modes of a normal moving image mode and a time lapse mode can be set as an imaging mode for acquiring a moving image. Note that the camera 1 can be set not only in the moving image mode but also in a normal still image mode for performing imaging for acquiring a still image.

  The normal moving image mode is a mode in which a plurality of image data acquired by continuously executing charge accumulation (imaging) using the image sensor 103 are sequentially connected and displayed (or recorded). In the time lapse mode, the image data for time lapse moving image (hereinafter referred to as “image data”) is based on a preset imaging interval (interval) from among a plurality of image data acquired by continuously performing imaging using the image sensor 103. , An appropriate image). In the time lapse mode, it is possible to display (or record) the images selected for the time lapse movie from consecutive frames of a normal movie by joining them in the order of acquisition (the order in which they were captured).

  In addition, the moving image acquired in the normal moving image mode has substantially the same time required for imaging for acquiring the moving image and the reproduction time of the moving image. On the other hand, in the time-lapse movie acquired in the time-lapse mode, the time required for imaging for acquiring the time-lapse movie differs from the playback time of the time-lapse movie.

  The time-lapse moving image acquired in the above-described time-lapse mode is a moving image obtained by joining intermittent image data in a predetermined period (total imaging time). Therefore, the moving image playback time is shortened with respect to the total imaging time (from the start to the end of imaging) for acquiring one time-lapse moving image. That is, in the normal moving image mode and the time lapse mode, when moving images having the same playback time are acquired, the total time for imaging for generating a moving image is different. Therefore, during moving image time-lapse shooting, it is desirable not to operate the aperture and the focus lens as much as possible in consideration of their mechanical durability. Therefore, in the time lapse mode, the camera 1 of the present embodiment is fixed (maintained) in the state (predetermined value) set at the time of the first imaging during imaging related to acquisition of the same time-lapse moving image.

  Note that the camera 1 of the present embodiment can further set individual modes in the above-described still image mode and moving image mode. For example, the camera 1 can set an automatic mode, a program mode, a shutter speed priority mode, an aperture priority mode, a manual mode, a depth of focus priority mode, a portrait mode, a landscape mode, a close-up mode, a sports mode, and a night scene mode.

  The shutter switch 131 is an operation member used when instructing the start of the imaging preparation operation or the imaging operation of the subject. The switch SW1 is turned on by the first stroke of the shutter switch 131 (for example, half-pressed). When the switch SW1 is turned on, an imaging preparation operation is started, and the system control unit 120 starts focus control, exposure control, auto white balance (AWB) processing, light emission control, and the like. Further, the switch SW2 is turned on by the second stroke (for example, full press) of the shutter switch 131. When the switch SW2 is turned on, an imaging operation is started, and the system control unit 120 starts an exposure process and a recording process related to charge accumulation (imaging) using the imaging element 103.

  In the exposure process, in response to an instruction from the system control unit 120, a signal read from the image sensor 103 is written into the image recording memory 113 as image data via the A / D conversion unit 106 and the memory control circuit 110. Then, in response to an instruction from the system control unit 120, development processing based on various calculations in the image processing circuit 107 and the memory control circuit 110 is performed on the image data, and the developed image data is stored in the image recording memory. 113 is written.

  In the recording process, the image data after the development process read from the image recording memory 113 is compressed by the compression / decompression circuit 111 in accordance with an instruction from the system control unit 120. Thereafter, in accordance with an instruction from the system control unit 120, the compressed image data is transferred to the external recording medium 200 via the first camera I / F 140, the first camera connector 141, the media connector 203, and the media I / F 202. It is written in the recording unit 201.

  The reproduction switch 132 is an operation member for instructing the start of reproduction processing for reading the acquired image data from the image recording memory 113 or the external recording medium 200 and displaying it on the image display unit 114. The operation unit 133 is an operation member used for various settings related to menu display and imaging, and various settings related to reproduction.

  Note that the imaging interval (fixed time interval) in the time lapse mode and the total imaging time obtained from the number of imaging operations can be set by the user operating the operation unit 133. In the time lapse mode, there are a technique for capturing an image without moving (fixing) the camera and a technique for so-called walk lapse for capturing an image while moving the camera.

  The power switch 134 is an operation member used to switch on / off of power supply from a power supply unit (battery) (not shown) to each unit of the camera 1. In addition, by operating the power switch 134, it is possible to switch on / off the power supply not only to the camera unit 100 but also to various accessory devices such as the lens unit 300 and the external recording medium 200 connected to the camera unit 100.

  The power supply control circuit 124 is a power supply control means including a battery detection circuit, a DC-DC converter, a switch circuit used for switching the energization block, and the like. Based on an instruction from the system control unit 120 according to the operation of the power switch 134, the power control circuit 124 detects the presence / absence of a battery, the type of battery, the remaining battery level, and supplies the necessary voltage for a necessary period. Only to each part of the camera 1.

  The second camera I / F 150 is provided on the camera mount unit 160 and is an interface for electrically connecting the camera unit 100 and the lens unit 300. The second camera connector 151 is a connection unit that electrically connects the camera unit 100 and the lens unit 300 via the lens connector 311 and the lens I / F 310. Note that the second camera connector 151 can transmit control signals, status signals, data signals, and the like and currents of various voltages between the camera unit 100 and the lens unit 300. The second camera connector 151 may be configured to transmit not only electrical communication but also optical communication, voice communication, and the like.

  The external recording medium 200 is an external recording device such as a memory card or a hard disk. The external recording medium 200 includes a recording unit 201 composed of a semiconductor memory, a magnetic disk, or the like, a media I / F 202 for the camera unit 100, and a media connector 203 for connecting to the camera unit 100.

  The lens unit 300 is an optical device that can be attached to and detached from the camera unit 100. The lens mount unit 320 is a connection unit that engages with the camera mount unit 160 and mechanically attaches the lens unit 300 to the camera unit 100. A lens connector 311 that electrically connects the lens unit 300 and the camera unit 100 is provided inside the lens mount unit 320. The lens connector 311 can transmit a control signal, a status signal, a data signal, etc., and receive various voltage currents between the lens unit 300 and the camera unit 100. The lens connector 311 may be configured to transmit not only electrical communication but also optical communication, voice communication, and the like.

  The imaging lens group 301 is an optical member including a focus lens, a zoom lens, a shift lens, and the like. The diaphragm 302 is a light amount adjusting member that adjusts the light amount of the light beam of the subject that passes through the imaging lens group 301 and enters the imaging element 103 side. A diaphragm control circuit 303 is a diaphragm control unit that controls the opening amount of the diaphragm 302 based on an instruction from the system control unit 120.

  The system control unit 120 instructs the aperture control circuit 303 to change the aperture diameter of the aperture 302 so that the aperture amount corresponds to the target aperture value. The aperture diameter of the diaphragm 302 being changed is sequentially detected by mutual communication between the lens unit 300 and the camera unit 100. Then, the system control unit 120 ends the change of the aperture diameter of the diaphragm 302 in response to the aperture diameter of the diaphragm 302 reaching the aperture diameter corresponding to the target aperture value.

  The lens control circuit 304 is a lens drive control unit that controls the operation (drive) of the imaging lens group 301. The lens control circuit 304 can detect the lens position (focus position) of the focus lens, and information regarding the detected lens position is transmitted to the camera unit 100 side.

  As described above, at the time of imaging a subject related to acquisition of a time-lapse movie in the time-lapse mode, the aperture control circuit 303 and the lens control circuit 304 are fixed so that the aperture value and the focal position when the first appropriate image is captured are fixed. Works.

  The lens system control unit 305 is a lens control unit that comprehensively controls the lens unit 300. The lens system control unit 305 includes a CPU (not shown), a volatile memory, and a non-volatile memory, and operation constants, variables, programs, and the like are stored in the volatile memory. The nonvolatile memory stores identification information such as a unique number related to the lens unit 300, management information, function information such as an open aperture value, a minimum aperture value, and a focal length. The basic configuration of the camera 1 has been described above.

(Time-lapse mode)
Hereinafter, the operation of the camera 1 when the imaging mode is set to the time lapse mode in the present embodiment will be described. FIG. 2 is a flowchart showing the operation sequence of the time lapse mode in the present embodiment. In the moving image time-lapse shooting in FIG. 2, the image sensor 103 continuously outputs images at a frame rate of, for example, 30 fps, and records only intermittent frames necessary for the time-lapse moving image in step S212 described later.

  In FIG. 2, in step S201, the mode dial 130 and the operation unit 133 are operated by the user to set the time lapse mode, and the photographing standby state is set. In step S202, the operation unit 133 can be used to select a shooting interval of time-lapse shooting, the number of shooting times, exposure control settings, a walk-lapse mode that is a special time-lapse mode in which a camera is carried while moving. Yes. The normal time lapse mode is a mode intended to intermittently image a subject without moving (fixing) the camera 1. On the other hand, the walk lapse mode is a mode in which the user intends to capture an image of the subject intermittently with the camera carried (with the camera 1 fixed). Therefore, the two modes differ in whether or not there is a change in the angle of view while acquiring the same time-lapse moving image.

  The exposure control setting here is to set whether to control exposure according to the exposure change during shooting (exposure tracking) or to fix the exposure control value at the start of shooting in time-lapse shooting. is there. Shooting with a fixed exposure control value is used for shooting in a situation where the brightness change of the subject is to be left as a time-lapse movie or in an environment where the brightness does not change. Shooting that changes the exposure control value (exposure control) is used when you want to maintain a constant exposure (or brightness) as the brightness of each image data for time-lapse movies even if the brightness of the subject changes. . In addition, the position detection circuit 118 can determine whether shooting with the camera 1 is indoor or outdoor.

  In step S203, if the exposure control setting is fixed exposure among the detailed settings of the time lapse shooting, the process proceeds to step S208 to select the control diagram 1 shown in FIG. 3 and perform exposure control (change exposure). If so, the process proceeds to step S204.

  In step S204, it is checked whether or not the walk lapse mode, which is one of the time lapse modes, is set. In the walk-lapse mode, the photographer performs time-lapse shooting in hand, so it is considered rare to continuously shoot for a long time spanning day and night. Therefore, it is determined that there is little change in luminance with time from day to night, and the process proceeds to step S208.

  The walk lapse mode may be determined based on an imaging mode manually set by the user, an output from a gyro sensor (not shown) provided in the camera 1, or a subject based on an acquired image. You may determine based on a motion vector.

  As described above, since it is assumed that the focus position is shifted due to a small change in luminance and because of hand-held shooting, the control diagram 1 having the deepest depth of field is selected as much as possible. On the other hand, if it is not walk-lapse shooting, the process proceeds to step S205.

  In step S205, it is checked whether the shooting location is indoor or outdoor. If the shooting location is indoor, it is determined that the shooting has little change in luminance, and the flow proceeds to step S208. If outdoor, the flow proceeds to S206.

  In step S206, the total imaging time is checked. If the determination result is less than the predetermined period, the process proceeds to step S207. If the determination result is greater than the predetermined period, the process proceeds to step S210. The total imaging time is the time from the start to the end of time-lapse imaging (time during image acquisition) obtained from the imaging interval and the number of imaging of time-lapse imaging.

  In step S207, the amount of luminance change within the imaging time is determined. This is because there may be a time zone in which the luminance change is large even if the total imaging time is shorter than the predetermined period. For example, in shooting such as dawn or dusk, the change in luminance increases even if the total imaging time is short. Therefore, it is determined whether the luminance change is large or small from the time when imaging starts and the total imaging time. It is determined whether to proceed or to proceed to step S210.

  In step S209, the control diagram 2 shown in FIG. 4 is selected for exposure control in the time lapse mode, and in step S210, the control diagram 3 shown in FIG. 5 is selected. When exposure control is executed by selecting this control diagram 2 or control diagram 3, the future exposure change direction is predicted from the time when shooting is started, as in the luminance change amount determination of step S207. The control may be corrected within the range of each control diagram. Specifically, if it can be predicted that the subject brightness will be dark, an aperture value on the open side with respect to the aperture value suitable for the current subject brightness is selected.

  The control diagram 1 will be described with reference to FIG. The control diagram 1 is a program diagram when the camera 1 captures a moving image at a frame rate of 30 fps, and selectively records a frame for a time-lapse moving image to acquire a time-lapse moving image. Here, the process proceeds to step S208 and the control diagram 1 is used when the change in luminance of the subject is not large, for example, when the exposure control setting is fixed at the determination in step S203. Therefore, in the time lapse mode, the exposure is actually determined using the control diagram 1 only at the time of the first imaging for acquiring the same moving image (for proper image acquisition), and other imaging. At times, fix the exposure.

  In FIG. 3, Tv changes from an upper limit of 1/2000 seconds (Tv11) to 1/30 seconds (Tv5) determined by the frame rate, and Sv can be set from ISO100 (Sv5) to ISO25600 (Sv13). The aperture value can be set from F2.0 (Av2) on the open side to F22 (Av9) on the small aperture side. Note that the shutter speed (exposure time) indicating the Tv value is controlled by the electronic shutter function of the image sensor 103.

  As described above, for example, when performing exposure control based on the control diagram 1, in the normal moving image mode, the luminance of the subject is tracked up to a subject having brightness corresponding to Ev0 to Ev21 in APEX units. Exposure control is possible. In this case, if the range in which the exposure can be tracked according to the change in luminance of the subject is defined as the interlocking range, when the control diagram 1 is used in the normal moving image mode, the amount corresponding to 22 steps of exposure is interlocked with the exposure. It becomes a range. However, as described above, in the time lapse mode, the aperture value set at the time of the first imaging (for obtaining an appropriate image) is also used at the time of the subsequent imaging, so that the exposure interlocking range is as much as the aperture value cannot be changed. Narrow. For example, when imaging a subject whose brightness at the start of imaging is Ev14 using the control diagram 1 in the time lapse mode, the aperture value is fixed at Av = 8, so the exposure interlocking range is Tv and Sv. This corresponds to 15 exposure levels that can be changed. Details of the exposure interlocking range described above will be described later with reference to FIG.

  If it is brighter than the room level of Ev6, reduce the aperture (below the predetermined value) to increase the depth of field as much as possible, widen the focus range, and focus even if the subject moves slightly. Like that. Also, if the accumulation time is shortened, when it is played back as a movie, the interval of the accumulation time between each frame constituting the moving image becomes large, and an unnatural movie whose subject motion is not smooth is acquired. May end up. In order to suppress this problem, the accumulation time in each moving image mode is relatively long in a range that can be set according to the frame rate. On the other hand, if it is darker than Ev6, the aperture value on the open side is set to make the exposure appropriate. However, as described above, when the aperture value is fixed in the time lapse mode, it may not be possible to cope with a generally assumed luminance change (Ev0: night view to Ev17: sunrise or sunset). Prepare a time-lapse diagram as shown.

  The control diagram 2 of FIG. 4 is a program diagram for time lapse imaging used when, for example, the total imaging time in the time lapse mode is relatively short. As described above, in the present embodiment, focus lens drive control (AF control) is not executed during time-lapse shooting. Therefore, the control diagram 2 is a diagram that assumes that the depth of field is as deep as possible, and that the change in exposure does not change significantly from the current luminance.

  The control diagram 3 of FIG. 5 is a program diagram for time lapse photography that is used, for example, when the subject is imaged across day and night with a relatively long total imaging time in the time lapse mode. When the control diagram 3 is used, it is a diagram that can cover the above-described general luminance change even when the luminance change of the subject is large, assuming that the luminance change is large.

  However, when performing exposure control based on the control diagram 3 in the time lapse mode, the brightness range in which the aperture value on the small aperture side can be set is narrower than in other control diagrams. Specifically, in the control diagram 2, the aperture value is Av8 when the brightness of the subject is Ev15 to 20 at the time of the first imaging in the time lapse mode, whereas in the control diagram 3, only in the case of Ev20, the aperture value is Av8. The aperture value is Av8. Therefore, when exposure control using the control diagram 3 is executed in the time lapse mode, the probability that an aperture value can be set so as to increase the depth of field is lower than when other control diagrams are used.

  As described above, in the normal moving image mode, the aperture value is sequentially changed according to the luminance change of the subject. Therefore, the exposure interlock range when executing the exposure control along the control diagram is 22 steps of exposure (Ev0 to Ev0). 21). On the other hand, in the time lapse mode, the aperture value can be changed only at the first imaging for acquiring the same moving image, and the aperture value at the first imaging is maintained at the second and subsequent imaging, The exposure interlocking range is 15 steps of exposure. That is, the exposure interlocking range in the time lapse mode is narrower than the normal moving image mode. For this reason, in the time lapse mode, the aperture value set at the time of the first imaging for acquiring the same moving image is important, and in order to suppress the change of the focus state between the appropriate images, the aperture value on the small aperture side is as much as possible. It is preferable that the aperture value can be set.

  FIG. 6 is a diagram illustrating an exposure interlocking range in the time lapse mode in the control diagram 1 by way of example. FIG. 7 is a diagram illustratively illustrating the interlocking range of exposure in the time lapse mode in the control diagram 2. FIG. 9 is a diagram illustratively explaining the interlocking range of exposure in the time lapse mode in the control diagram 3. 6 to 8 exemplify the interlocking range of exposure when the brightness of the subject is Ev14 at the time of the first imaging for acquiring the same moving image in the time lapse mode.

  For example, as illustrated in FIG. 6, in the control diagram 1, the aperture value Av is fixed to 8 and the exposure interlocking range is 15 steps of Ev6 to Ev20. As shown in FIG. 7, in the control diagram 2, the aperture value Av is fixed to 7 and the exposure interlocking range is 15 steps of Ev5 to Ev19. As shown in FIG. 8, in the control diagram 3, the aperture value Av is fixed to 5 and the exposure interlocking range is 15 steps of Ev3 to Ev17.

  As shown in FIGS. 6 to 7, the control diagram 2 is a line in which the aperture value on the small aperture side is more easily set than the control diagram 1 while covering the general luminance change as described above. It is a figure, Comprising: It adjusted so that the depth of field in an appropriate image may become deep. The exposure control using the control diagram 2 is executed when the total imaging time for executing intermittent imaging is short and the luminance of the subject changes to a small width. Therefore, the camera 1 of the present embodiment can select the control diagram 2 to perform exposure control that can easily focus on the subject to be imaged while covering the luminance change of the general subject as described above. It is.

  On the other hand, as shown in FIGS. 6 to 8, the control diagram 3 is a diagram in which the aperture value on the open side can be set more easily than the control diagram 1 or the control diagram 2. The depth of field is adjusted to be relatively shallow. The exposure control using the control diagram 3 is executed when the total imaging time for executing intermittent imaging is long and the luminance of the subject changes significantly. Therefore, the camera 1 of the present embodiment can perform exposure control that covers the change in luminance of the general subject and the change in ambient light over time as described above by selecting the control diagram 3. .

  Returning to FIG. 2, when a program diagram corresponding to each time-lapse shooting setting is selected, in step S <b> 211, the process waits for notification of a shooting start instruction. If a shooting start instruction is received in step S211, it is confirmed in step S212 whether the recording timing is for time-lapse shooting. If it is the recording timing, the process proceeds to step S213, and the frame is captured for the time-lapse moving image.

  In step S214, an instruction to interrupt or end time-lapse shooting is checked, and if an instruction to stop or end is issued, the process proceeds to step S215 to end time-lapse shooting.

  As described above, according to the above-described embodiment, the aperture control is not performed during shooting by switching the program diagram for controlling the exposure at the start of imaging according to the total imaging time of time-lapse movie shooting. However, it is possible to obtain an image with good exposure.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these, A various deformation | transformation and change are possible within the range of the summary. For example, the various values of Tv, Av, Sv, and Ev in the various program diagrams in the above-described embodiment are not limited to the values shown in the figure, and appropriate control can be performed by setting the time-lapse shooting and the total imaging time. Any configuration may be used as long as it is switched.

  In the above-described embodiment, the components of the camera 1 such as the image processing circuit 107, the memory control circuit 110, and the system control unit 120 operate in cooperation with each other to control the operation of the camera 1. However, the present invention is not limited to this. For example, a (computer) program according to the flowchart shown in FIG. 2 described above is stored in the main memory 121 in advance. And the structure which controls the operation | movement of the camera 1 by the system control part 120 containing a microcomputer etc. may be sufficient as the said program. Moreover, as long as it has the function of a program, it does not ask | require the form of programs, such as an object code, the program run by an interpreter, and the script data supplied to OS. The recording medium for supplying the program may be, for example, a magnetic recording medium such as a hard disk or a magnetic tape, or an optical / magneto-optical recording medium.

  In the above-described embodiment, a digital camera with an interchangeable lens and an optical viewfinder has been described as an example of the imaging apparatus of the present invention. However, the present invention is not limited to this. For example, an imaging apparatus other than a digital camera, such as a digital camera without an optical finder, a lens-integrated digital camera, a portable device such as a digital video camera or a smartphone, a wearable terminal, or a security camera may be employed.

(Other embodiments)
In addition, the present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read the program. It can also be realized by executing processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1: Digital camera, 100: Camera unit, 113: Image recording memory, 120: System control unit, 200: External recording medium, 300: Lens unit

Claims (14)

In order to acquire a time-lapse moving image obtained by connecting a plurality of images acquired by intermittently capturing a subject, the imaging unit is intermittently used to capture a subject image and acquire the image. An imaging device that performs accurate imaging,
Aperture,
Exposure control means for setting the aperture value of the aperture used for the intermittent imaging;
Have
The exposure control means maintains the aperture value used for intermittent imaging based on a total imaging time for acquiring the same time-lapse movie at a predetermined value during acquisition of the same time-lapse movie. An imaging device that is characterized.   The imaging apparatus according to claim 1, wherein the exposure control unit sets the predetermined value by switching a plurality of program diagrams stored in a memory based on the total imaging time. Determining means for determining whether or not the total imaging time is equal to or longer than a predetermined period;
The imaging apparatus according to claim 2, wherein the exposure control unit switches the plurality of program diagrams based on a determination result of the determination unit.   The exposure control means determines the predetermined value when the determination means determines that the total imaging time is shorter than the predetermined period, and the determination means determines that the total imaging time is equal to or longer than the predetermined period. The imaging apparatus according to claim 3, wherein an aperture value on a small aperture side that is equal to or smaller than the predetermined value is set.   5. The exposure control unit according to claim 2, wherein the exposure control unit switches the plurality of program diagrams in accordance with a magnitude of luminance change of a subject during a period in which the same time-lapse moving image is acquired. The imaging apparatus according to item 1.   The said exposure control means predicts the length of the said total imaging time according to imaging | photography mode, and sets the said predetermined value according to this prediction, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The imaging device described. The shooting mode includes a first mode in which the intermittent imaging is performed without moving the imaging device, and a second mode in which the intermittent imaging is performed while carrying the imaging device,
The exposure control means sets the shooting mode to the second mode when the luminance of the subject is within a predetermined brightness range, compared to when the shooting mode is set to the first mode. The imaging apparatus according to claim 6, wherein, when set, the predetermined value is set as a diaphragm value on a small diaphragm side.   When the luminance of the subject is within a predetermined brightness range, the exposure control means sets the predetermined value when the imaging device is outdoors rather than when the imaging device is indoors. The imaging apparatus according to claim 1, wherein the imaging device is set to a diaphragm value on a small diaphragm side.   The said exposure control means sets the said predetermined value based on the time which starts the said intermittent imaging for acquiring the same said time-lapse moving image, and the said total imaging time. The imaging device according to any one of 1 to 8. A moving image generating means for generating the time-lapse moving image by connecting a plurality of images acquired by the intermittent imaging,
The moving image generating means selects the images corresponding to a predetermined time interval from a plurality of images acquired by imaging the subject based on a fixed frame rate by the imaging means and joins the time-lapse moving images. The imaging device according to claim 1, wherein the imaging device is generated.   The exposure control means adjusts the charge accumulation time in the imaging means by an electronic shutter function in accordance with the brightness of the subject and the predetermined aperture value during the same time-lapse movie acquisition period. The image pickup apparatus according to claim 1, wherein exposure control is performed by using the image pickup apparatus. In order to acquire a time-lapse moving image obtained by connecting a plurality of images acquired by intermittently capturing a subject, the imaging unit is intermittently used to capture a subject image and acquire the image. A method for controlling an imaging apparatus that performs various imaging,
An exposure control step of setting an aperture value of an aperture used for the intermittent imaging;
In the exposure control step, based on a total imaging time for acquiring the same time-lapse movie, maintaining the aperture value used for intermittent imaging at a predetermined value while acquiring the same time-lapse movie. A control method for an imaging apparatus.   The program for making a computer perform each process of the control method of Claim 12.   A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 12.

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