JP6653845B1 - Imaging device, imaging method, and program - Google Patents

Abstract

A live view display is performed by simulating pseudo ND filter photographing before photographing. A photographing apparatus includes an imaging unit, a first synthesis unit, a first gain application unit, a second synthesis unit, a second gain application unit, and a display unit. The imaging unit 20 acquires the first image data at the first exposure time, and acquires the second image data at the second exposure time. The first synthesizing unit 61 adds and synthesizes the plurality of first image data acquired until the total exposure time reaches the third exposure time, and the first gain applying unit 62 applies the first gain to the first synthesized image data and sets ND First still image data having a first brightness corresponding to the brightness reduced by the filter is generated. The second combining unit 63 sequentially adds and combines the second image data, and the second gain applying unit 64 applies the second gain to the second combined image data to generate first live view image data of the first brightness. . The display unit displays the first live view image at a frame rate for displaying a live view image. [Selection diagram] FIG.

Description

  The disclosure of the present specification relates to an imaging device, an imaging method, and a program.

  2. Description of the Related Art Conventionally, in the field of photographing apparatuses, a photographing method is known in which light is reduced using an ND (Neutral Density) filter, a slow shutter effect is produced by extending an exposure time, and overexposure of a high-luminance subject is prevented. ing. However, in the device configuration in which the ND filter is manually attached / detached, the work load associated with the attachment / detachment is a problem. Usually, the ND filter is used by combining a plurality of ND filters. Therefore, the combination of the ND filters themselves is complicated. Further, resetting operations such as ISO sensitivity, shutter speed, and aperture which occur after the ND filter is mounted and light is reduced is complicated. In addition, when the ND filter is mounted in a dark environment, there is a problem of visibility that a finder cannot be seen. Not only an optical viewfinder but also an EVF (Electronic View Finder) is a problem because the amount of incident light is reduced. In addition, it is necessary to prepare photographing equipment, which places a burden on the user. Further, in a device configuration in which an ND filter is built in and inserted into and removed from the optical path, there is a problem that the size and cost of the imaging device are increased.

  A technique related to such a problem is described in Patent Document 1. Patent Literature 1 discloses a technique for reproducing a pseudo image using an ND filter by combining divisional exposure and image processing for the purpose of preventing overexposure of a high-luminance subject. Hereinafter, imaging that reproduces imaging using an ND filter without using a physical ND filter is referred to as pseudo ND filter imaging.

  Patent Document 2 discloses a technique in which pseudo ND filter photographing is applied in moving image photographing for the purpose of preventing overexposure. Further, Patent Document 3 discloses a technique in which each playback frame designated by a user as a target of synthesis from a recorded moving image file is read and edited to generate a still image. Patent Literature 4 describes an image processing technique for adding a special effect in a moving image such as multi-echo processing during recording of a moving image. Patent Literature 5 describes a technique for reproducing and editing a reproduced image to correct the exposure amount after the end of image capturing, and to regenerate the synthesized image. Patent Literature 6 discloses a technique in which a reproduced image is reproduced and edited after photographing to add an image effect in first-curtain synchronization / second-curtain synchronization / multi-emission.

JP-A-2015-136087 JP-A-2006-058808 JP-A-2005-103119 JP-A-2006-048968 JP-A-2017-015276 JP 2009-232383 A

  In conventional ND filter photography and pseudo ND filter photography, setting of appropriate photographing conditions including ND magnification of photographing that takes several seconds to several tens of seconds is complicated and difficult, and a slow shutter effect is produced until photographing is completely completed. Still images are not displayed. For this reason, re-imaging will greatly waste time, and a technique for simulating the brightness and the slow shutter effect associated with the ND magnification of ND filter imaging before the start of imaging is expected. Note that Patent Literatures 1 to 5 describe a technique of pseudo ND filter imaging or an imaging technique similar thereto, but in any of the literatures, using an ND filter before starting imaging, the “brightened light with reduced light” is used. And a technique for simulating pseudo ND filter photographing before starting photographing in order to judge whether the setting is appropriate or not. It has not been.

  In view of the above situation, an object of one aspect of the present invention is to provide a technique for simulating pseudo ND filter photographing before photographing and performing live view display.

  An imaging device according to one embodiment of the present invention is an imaging unit which captures an image of a subject, acquires first image data for recording a still image at a first exposure time, and acquires live image display at a second exposure time. An image capturing unit that acquires second image data; a first combining unit that adds and combines a plurality of first image data repeatedly acquired by the image capturing unit until a first total exposure time reaches a third exposure time; A first gain application unit configured to generate a first still image data having a first brightness by applying a first gain to the first combined image data output from the first combining unit; A second combining unit for sequentially adding and combining the second image data; and a second unit having the first brightness by applying a second gain to the second combined image data sequentially output from the second combining unit. 1 Generate live view image data A gain applying unit, wherein the second gain is applied each time the second combined image data is output from the second combining unit; and a second gain applying unit. A display unit that updates the first live view image at the frame rate for displaying the live view image in the imaging unit and displays the first live view image based on the first live view image data generated in step (a).

  According to an imaging method of one embodiment of the present invention, first combined image data is generated by adding and combining a plurality of first image data repeatedly acquired until a first total exposure time reaches a third exposure time. Each of the plurality of first image data is image data for recording a still image, is acquired at a first exposure time, and applies a first gain to the first composite image data to obtain a first image data. Generating first still image data having brightness, and before generating the first combined image data, sequentially adding and combining the second image data to generate second combined image data; The two image data is image data for displaying a live view image, is acquired at a second exposure time, and applies a second gain to the second combined image data before generating the first combined image data. The first brightness Generating first live-view image data, wherein the second gain is applied each time the second composite image data is generated, and the first gain is generated before the first composite image data is generated. Based on the live view image data, the first live view image is updated and displayed at the live view image display frame rate.

  A program according to an aspect of the present invention is an imaging unit that captures an image of a subject, acquires first image data for recording a still image at a first exposure time, and obtains first image data for live view image display at a second exposure time. The first synthesizing is performed by adding and synthesizing a plurality of pieces of first image data repeatedly acquired by the imaging unit until the first total exposure time reaches a third exposure time in an imaging apparatus including the imaging unit that acquires two image data. By generating image data and applying a first gain to the first combined image data, first still image data having a first brightness is generated, and before the first combined image data is generated, A second combined image data is generated by sequentially adding and combining the second image data acquired by the imaging unit, and a second gain is applied to the second combined image data before generating the first combined image data. By applying Generating first live view image data having a first brightness, wherein the second gain is applied each time the second composite image data is generated, and before generating the first composite image data, Based on the first live view image data, a process of updating and displaying a first live view image at a frame rate for displaying the live view image in the imaging unit is executed.

  According to the above aspect, it is possible to simulate the pseudo ND filter photographing before photographing and perform live view display.

FIG. 2 is a diagram illustrating a configuration of the photographing apparatus 1. FIG. 2 is an external view of the photographing device 1. FIG. 2 is a diagram illustrating a functional configuration of the photographing apparatus 1. It is a figure showing the flow of photography processing. FIG. 3 is a diagram illustrating an example of a live view image. FIG. 9 is a diagram illustrating another example of the live view image. FIG. 11 is a diagram showing still another example of the live view image. It is a flowchart of a pseudo ND photography button process. It is a flowchart of dial rotation processing during button press. FIG. 9 is a diagram for explaining a method of roughly changing the dimming rate. It is a figure for explaining a method of changing a dimming rate finely. It is a flowchart of a button short press dial rotation process. FIG. 6 is a diagram illustrating an example of a dimming rate setting screen. FIG. 9 is a diagram for explaining a method of changing an ND filter type. It is a figure for explaining a method of changing a target item. It is a flowchart of a dimming rate automatic setting process. It is a flowchart of a photography process. It is a flowchart of pre-processing. It is a modification of the flowchart of the preprocessing. It is a flowchart of an exposure time setting process. It is a flowchart of an exposure time setting process for manual ND. It is a flowchart of a continuity calculation process. It is a modification of the flowchart of the continuity calculation process. It is the figure which showed an example of the warning display regarding continuity. It is a flowchart of a reproducibility calculation process. It is a modification of the flowchart of the reproducibility calculation process. It is a modification of the flowchart of the manual ND exposure time setting processing. 9 is a flowchart of an automatic ND exposure time setting process. It is a flowchart of a live simulation process. It is a flowchart of a pseudo ND filter imaging process. It is a flowchart of a multi-shooting process. FIG. 3 is a diagram illustrating an example of a still image. It is a figure for explaining setting of a pseudo ND filter of a half type. FIG. 4 is a diagram for describing a pixel line of a still image. FIG. 9 is a diagram illustrating an example of a pseudo ND filter table. FIG. 9 is a diagram illustrating a modified example of the functional configuration of the photographing device 1. It is a modification of the flowchart of the button short press dial rotation processing. FIG. 7 is a diagram illustrating an example of a twin shutter speed setting screen. FIG. 9 is a diagram showing still another modified example of the functional configuration of the photographing device 1.

  FIG. 1 is a diagram exemplifying a configuration of the photographing device 1. FIG. 2 is an external view of the photographing device 1. The imaging device 1 performs pseudo ND filter imaging for reproducing imaging using an ND filter in a pseudo manner by a combination of divided exposure and image processing. In addition, before photographing a still image by pseudo ND filter photographing, the photographing apparatus 1 simulates pseudo ND filter photographing and performs live view display.

  Hereinafter, the configuration of the photographing apparatus 1 will be described with reference to FIGS. 1 and 2. Hereinafter, the case where the photographing device 1 is a digital camera will be described as an example. However, the photographing device 1 only needs to have a photographing function, and is not limited to a digital camera. The imaging device 1 may be, for example, a mobile terminal such as a smartphone, a mobile phone, or a tablet computer. The imaging device 1 may be, for example, a stationary computer, a microscope, or the like.

  The photographing apparatus 1 includes a display unit 2 as shown in FIGS. The display unit 2 is, for example, a liquid crystal display (LCD), an organic EL display, or the like provided on the back of the imaging device 1, and displays a live view image generated by simulating pseudo ND filter imaging.

  As shown in FIG. 1, the imaging device 1 further includes an imaging unit 20, a memory 26, a system control unit 27, an imaging control unit 28, a shutter control unit 29, an aperture control unit 30, a lens control unit 31, and an AF processing unit 32. , Exposure control unit 33, camera shake detection unit 34, image processing unit 35, power supply unit 36, power supply control unit 37, operation unit 38, external memory 39, nonvolatile memory 40, flash control unit 41, flash charging unit 42, and flash The light emitting section 43 is provided.

  The imaging unit 20 includes a lens 21, an aperture 22, a mechanical shutter 23, an imaging element 24, and an A / D conversion unit 25, and captures an image of a subject to acquire image data of the subject.

  The lens 21 is a single focus lens or a zoom lens, and includes one or a plurality of optical lenses for forming an optical image of a subject. The movement of some or all of the optical lenses that constitute the lens 21 is controlled by the lens control unit 31, thereby performing focusing, zooming, and the like.

  The diaphragm 22 limits the amount of light incident on the image sensor 24 by blocking light incident on the image capturing apparatus 1. The aperture diameter of the aperture 22 is controlled by the aperture control unit 30, whereby the light amount and the depth of field are adjusted.

  The mechanical shutter 23 switches between an exposure state in which light is incident on the image sensor 24 and a light-shielded state in which light is not incident on the image sensor 24. The opening and closing of the mechanical shutter 23 is controlled by the shutter control unit 29, thereby switching between the exposure state and the light shielding state.

  The imaging element 24 is, for example, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like, and includes a plurality of two-dimensionally arranged photodiodes each forming a pixel. . When the photodiode generates a current corresponding to the amount of received light, electric charges are accumulated in a capacitor connected to the photodiode. The exposure time and the frame rate of the imaging device 24 are controlled by the imaging control unit 28, whereby image data is output from the imaging device 24.

  The A / D converter 25 converts image data, which is analog data, output from the image sensor 24 into image data, which is digital data, and outputs the digital image data to the memory 26.

  The memory 26 is an electrically rewritable volatile memory for temporarily storing image data, and is, for example, an SDRAM (Synchronous Dynamic Random Access Memory).

  The system control unit 27 is an electric circuit that controls the photographing device 1. The system control unit 27 includes a processor and a memory, and may be, for example, an electric circuit in which they are integrated on one chip. The system control unit 27 is connected to various control units (an imaging control unit 28, a shutter control unit 29, an aperture control unit 30, a lens control unit 31, an AF processing unit 32, an exposure control unit 33, a flash control unit 41, and the like). I have.

  The AF processing unit 32 performs an autofocus process based on the image data. The exposure control unit 33 is an example of a photometry unit, and detects a subject luminance based on image data. The camera shake detection unit 34 detects a camera shake amount generated in the imaging device 1.

  The image processing unit 35 is an electric circuit that reads image data from the memory 26 and performs various image processing. The image processing unit 35 performs, for example, image synthesis processing performed by pseudo ND filter shooting in addition to basic image processing such as optical black subtraction processing, white balance correction processing, demosaicing processing, and color matrix processing.

  The power supply unit 36 may be, for example, a primary battery, a secondary battery, or the like, or may be an AC adapter connected to a commercial power supply. The power supply control unit 37 is a power supply circuit that supplies power supplied from the power supply unit 36 to each unit of the imaging device 1.

  The operation unit 38 is a member provided for a user's operation. For example, a pseudo ND photographing button 3, a photographing mode dial 4, a zoom ring 5, a manual focus ring 6, a shutter button 7, and an F dial shown in FIG. 8, an enlarge button 9, a moving image button 10, an LV mode button 11, an R dial 12, and the like.

  The external memory 39 is a recording medium detachable from the photographing device 1, and is, for example, a memory card. The nonvolatile memory 40 is, for example, a flash memory. In the external memory 39, for example, still image data obtained by pseudo ND filter shooting is recorded.

  The flash control unit 41 controls a flash charging unit 42 and a flash emission unit 43. The flash control unit 41 uses the energy stored in the flash charging unit 42 to cause the flash light emitting unit 43 to perform a light emitting operation.

  FIG. 3 is a diagram illustrating a functional configuration of the photographing apparatus 1. As shown in FIG. 3, the imaging device 1 includes an exposure time setting unit 50, an image generation unit 60, a still image recording unit 70, and a live ND filter imaging component. A view image display section 80 and an exposure time display section 90 are provided.

  The exposure time setting unit 50 includes a light reduction rate setting unit 51, and based on the light reduction rate set for recording a still image in pseudo ND filter shooting, a first exposure time, a second exposure time, and a third exposure time. Set the time. When the operation unit 38 receives an operation of a user who specifies the dimming rate, the dimming rate setting unit 51 sets the dimming rate specified by the user. The functions of the exposure time setting unit 50 and the dimming rate setting unit 51 are realized by, for example, the system control unit 27 illustrated in FIG.

  The first exposure time is an exposure time for generating a still image with reduced brightness in pseudo ND filter imaging, and is set in the image sensor 24 when generating still image data. In the present embodiment, the first exposure time is an exposure time that determines the first brightness that has been reduced according to the reduced light amount of the pseudo ND filter imaging. However, it is not necessary to change the first exposure time according to the reduced light amount. Instead, for example, the frame time may be fixed to the maximum frame rate of the main exposure reading control. When performing pseudo ND filter imaging, the imaging unit 20 continuously and repeatedly acquires image data of the first exposure time under the main exposure reading control. Note that the first exposure time is preferably a time during which the output voltage of each pixel is not saturated.

  The second exposure time is set in the image sensor 24 when generating the live view image data. The imaging unit 20 acquires image data at the second exposure time when simulating the pseudo ND filter imaging. The second exposure time may be, for example, a time (for example, 1/120 s) corresponding to the display frame rate of the live view image (for example, 120 fps). Here, the display frame rate of the live view image may fluctuate in accordance with the brightness within a range that does not impair subject tracking, which is an original finder function. In order to accurately simulate the live view up to the saturation state, imaging control by main exposure reading control is performed with the same aperture value as that at the time of main exposure in still image shooting, and the second exposure time is set to the same as the first exposure time. It is desirable to do. Alternatively, since the main exposure readout control is, for example, 60 fps at maximum, it is desirable to set the live view frame rate to 60 fps, but if not, it is configured to separately display a saturation warning display on the live view. You may.

  The third exposure time is an exposure time that determines the tracking time of the movement of the subject, and determines the flow rate of the subject image, that is, the slow shutter effect. Note that the third exposure time is longer than the first exposure time.

  The extinction ratio is the reciprocal of the value of the ND filter simulated in pseudo ND filter imaging (also referred to as ND magnification). For example, when the ND filter of ND2 is simulated, the ratio is 1/2, and when the ND filter of ND400 is simulated, the ratio is 1/400.

  The image generation unit 60 combines the image data in the simulation of the pseudo ND filter shooting and the simulation of the pseudo ND filter shooting to generate image data for live view display or image data for recording a still image. The image generation section 60 includes a first synthesis section 61, a first gain application section 62, a second synthesis section 63, and a second gain application section 64. The first combining unit 61 and the first gain applying unit 62 are used in pseudo ND filter imaging, and the second combining unit 63 and the second gain applying unit 64 are used in simulation of pseudo ND filter imaging. The function of the image generation unit 60 is realized by, for example, the image processing unit 35 illustrated in FIG.

  The first synthesis unit 61 adds and synthesizes a plurality of first image data repeatedly acquired by the imaging unit 20 until the total exposure time in the pseudo ND filter imaging reaches the third exposure time. Then, the first combining unit 61 generates the first combined image data by the addition combining process. The first image data is image data acquired for recording a still image by pseudo ND filter imaging, and is acquired at the first exposure time. Hereinafter, the total exposure time in the pseudo ND filter imaging is referred to as a first total exposure time.

The first gain application unit 62 generates first still image data having a brightness based on the dimming rate by applying the first gain to the first combined image data output from the first combining unit 61. Note that the brightness based on the dimming rate means the brightness corresponding to the first exposure time (hereinafter, referred to as the first brightness), and the first exposure time is defined as the maximum frame rate of the main exposure reading sequence. May be configured to be a fixed brightness different from the first brightness. The first gain is calculated by the following equation (1).
First gain = third exposure time × dimming rate / first total exposure time (1)

  If the first total exposure time coincides with the third exposure time, the first gain is the dimming rate itself set by the dimming rate setting unit 51, and is the reciprocal of the ND magnification of the pseudo ND filter. is there.

  The second combining unit 63 sequentially adds and combines the second image data acquired by the imaging unit 20. Then, the second synthesis unit 63 generates the second synthesized image data by the addition synthesis process. The second image data is image data acquired for displaying a live view image simulating the pseudo ND filter imaging, and is acquired at the second exposure time. Hereinafter, the total exposure time in the simulation of the pseudo ND filter imaging is referred to as a second total exposure time.

The second gain applying unit 64 applies a second gain to the second combined image data sequentially output from the second combining unit 63, thereby obtaining a brightness corresponding to still image data recorded as a product of ND filter imaging. The first live view image data having the length is generated. That is, the first live view image data having the first brightness is generated. The second gain is calculated by the following equation (2) every time the second combined image data is output from the second combining unit.
Second gain = third exposure time × dimming rate / second total exposure time (2)

  The still image recording unit 70 records the first still image data generated by the first gain application unit 62 as a result of the pseudo ND filter imaging. Note that the function of the still image recording unit 70 is realized by, for example, the external memory 39 shown in FIG.

  The live view image display unit 80 updates the first live view image at the frame rate for live view image display in the imaging unit 20 based on the first live view image data generated by the second gain application unit 64. To display. Note that the function of the live view image display unit 80 is realized by, for example, the display unit 2 illustrated in FIG.

  The exposure time display section 90 displays the third exposure time set by the exposure time setting section 50. Note that the function of the exposure time display unit 90 is realized by, for example, the display unit 2 illustrated in FIG.

  FIG. 4 is a diagram illustrating a flow of the photographing process performed by the photographing apparatus 1. In the photographing apparatus 1, for example, the system control unit 27 executes a predetermined program, so that the components illustrated in FIG. 3 function, and from the simulation of the pseudo ND filter photographing to the pseudo ND filter photographing illustrated in FIG. A series of photographing processing is performed.

  When the photographing process shown in FIG. 4 is started, the photographing apparatus 1 first sets a dimming rate for recording a still image (step S1). Here, for example, the dimming rate setting unit 51 sets the dimming rate based on the ND magnification specified by the user of the imaging device 1 operating the operation unit 38.

  Next, the photographing apparatus 1 sets an exposure time (Step S2). Here, the exposure time setting unit 50 sets the first exposure time and the third exposure time based on the dimming rate set in step S1, and sets the first exposure time and the third exposure time based on the frame rate for live view image display. 2 Set the exposure time. The frame rate for displaying a live view image is also simply referred to as the live view frame rate.

  In particular, regarding the first exposure time and the third exposure time, the exposure time setting unit 50 sets the first exposure time and the third exposure time based on the dimming rate and one of the first exposure time and the third exposure time. The other of the exposure times is calculated. More specifically, the exposure time setting unit 50 sets the first exposure time so that the ratio of the first exposure time to the third exposure time (= first exposure time / third exposure time) matches the dimming rate. And the other of the third exposure time.

  For example, the exposure time setting unit 50 may set the exposure time estimated by the photographing apparatus 1 to perform the automatic exposure (AE) control as the first exposure time. In that case, the first exposure time is reduced. The third exposure time may be calculated by dividing the third exposure time. In addition, the exposure time setting unit 50 may set the time manually set by the user as the third exposure time. In this case, the manually set third exposure time is multiplied by the extinction ratio, The first exposure time may be calculated.

  When the setting of the exposure time is completed, the photographing apparatus 1 starts the simulation of the pseudo ND filter photographing, and repeats the processing of steps S3 to S7 until there is a photographing instruction of the pseudo ND filter photographing in step S8.

  First, the imaging device 1 acquires image data for a live view image (step S3). Here, the imaging control unit 28 sets the second exposure time set in step S2 to the image sensor 24, and the imaging unit 20 acquires the second image data for live view image display at the second exposure time.

  Next, the imaging device 1 combines the image data acquired in step S3 (step S4). Here, the second combining unit 63 sequentially adds and combines the second image data acquired by the imaging unit 20 at the second exposure time to generate second combined image data.

  Further, the imaging device 1 calculates a gain (Step S5). Here, the second gain application section 64 calculates the second gain by the above-described equation (2).

  When the gain is calculated, the imaging device 1 generates live view image data (Step S6). Here, the second gain application unit 64 generates the first live view image data by applying the second gain to the second composite image data.

  Thereafter, the imaging device 1 displays the live view image (Step S7). Here, the live view image display unit 80 updates and displays the first live view image at the frame rate for live view image display based on the first live view image data generated in step S6. Further, the exposure time display section 90 may display the third exposure time.

  The live view image 100 shown in FIG. 5 is an example of the live view image displayed on the display unit 2 at the time when 0.5 seconds have elapsed from the start of the simulation, and the live view image 101 shown in FIG. It is an example of the live view image displayed on the display unit 2 at the time point when it has elapsed. Note that the mark 200 indicates the third exposure time. The marks 201 and 201a show the relationship between the third exposure time and the second total exposure time. More specifically, the mark 201 and the mark 201a are a ring graph indicating the ratio of the second total exposure time to the third exposure time, and a numerical value indicating the second total exposure time provided in the ring graph, It is composed of In other words, the ring graph indicates the ratio of the exposure time corresponding to the second combined image data to the third exposure time. A mark 202 indicates an ND magnification in pseudo ND filter imaging.

  In step S8, when the photographing instruction is detected, the photographing device 1 starts pseudo ND filter photographing. The shooting instruction is, for example, pressing of the shutter button 7 or the like.

  First, the photographing device 1 acquires image data for a plurality of still images (step S9). Here, the imaging control unit 28 sets the first exposure time set in step S2 to the image sensor 24, and the imaging unit 20 acquires the first image data for displaying a still image with the first exposure time. The imaging unit 20 acquires a plurality of first image data by repeating acquisition of the first image data until the first total exposure time reaches the third exposure time.

  Next, the imaging device 1 combines the image data acquired in step S9 (step S10). Here, the first combining unit 61 adds and combines the plurality of first image data acquired by the imaging unit 20 to generate first combined image data.

  Further, the imaging device 1 calculates a gain (Step S11). Here, the first gain application unit 62 calculates the first gain by the above-described equation (1).

  When the gain is calculated, the imaging device 1 generates still image data (Step S12). Here, the first gain application unit 62 generates the first still image data by applying the first gain to the first composite image data.

  Finally, the imaging device 1 records the still image data (Step S13). Here, the still image recording unit 70 records the first still image data generated in step S12.

  As shown in FIG. 4, the imaging device 1 can perform the pseudo ND filter imaging after displaying the live view image obtained by simulating the pseudo ND filter imaging. Therefore, by viewing the live view image, the user can confirm the slow shutter effect of the image obtained by the pseudo ND filter imaging. As a result, it is possible to avoid failure of pseudo ND filter imaging, that is, a situation in which an image obtained by pseudo ND filter imaging is significantly different from an image expected by a user. For this reason, it is possible to prevent a large amount of time from being wasted due to redoing of photographing.

  As described above, the imaging device 1 performs live view display of an image simulating the pseudo ND filter imaging before the pseudo ND filter imaging. On the other hand, for example, a technique of performing a multi-echo process during recording of a moving image and giving a special effect described in Patent Document 4 is similar in displaying a composite image, but still image shooting using an ND filter is performed live. It does not simulate on the view and does not change the shooting conditions of a specific still image by further simulating. Further, the techniques described in Patent Literature 5 and Patent Literature 6 are techniques for synthesizing and editing an image to reproduce and display the image after photographing is completed. These techniques also do not simulate the specific still image photographing conditions on a live view, and in that respect, are larger than the photographing apparatus 1.

  Further, the photographing apparatus 1 displays the live view image at the same brightness as the dimmed still image, and simultaneously displays the slow shutter effect. Further, since the slow shutter effect is automatically reset in response to the change of the photographing condition and the photographing is restarted, not only it contributes to avoiding the redoing of the photographing, but also enables a quick redoing.

  Further, the imaging device 1 displays a live view image immediately after starting the simulation of the pseudo ND filter imaging. Since the user can confirm the slow shutter effect according to the elapsed time from the start of the simulation in the live view image, the user can see the live view image 100 and the live view image 101 shown in FIGS. 5 and 6, for example. , The slow shutter effect obtained in the third exposure time can be expected. Therefore, the user can confirm that the required slow shutter effect can be obtained before the third exposure time elapses from the start of the simulation, so that the pseudo ND filter imaging can be performed early while avoiding re-imaging. Can be started.

  Further, as described above, since the user can check the slow shutter effect according to the elapsed time from the start of the simulation in the live view image, the third exposure set for the expected slow shutter effect is performed. It is possible to know that the time is too long or too short. Therefore, the appropriate setting of the exposure time can be grasped before the pseudo ND filter photographing, and the failure of the pseudo ND filter photographing can be avoided by reviewing the setting.

  5 and 6 show an example in which the display unit 2 displays the third exposure time out of the first exposure time to the third exposure time. However, as shown in FIG. The first exposure time may be displayed in addition to the third exposure time. In this case, the first exposure time and the third exposure time may be indicated by marks (marks 200a and marks 204a) that can be distinguished. The mark 200a indicates a third exposure time indicating the degree of flow of the subject image, and the mark 204a indicates a first exposure time indicating the brightness of the image.

  Thereby, in addition to the relationship between the slow shutter effect and the third exposure time, the relationship between the brightness of the image and the first exposure time can be grasped by checking the live view image and the mark. Therefore, the user can adjust the brightness of the image by changing the first exposure time as needed. Further, the configuration may be changed so that the user can individually set the first exposure time (mark 200a) and the third exposure time (mark 204a), and calculate and display the ND magnification (mark 200). .

  Hereinafter, the processing performed by the imaging device 1 will be described in more detail. First, a simulation of pseudo ND filter imaging and a setting operation of pseudo ND filter imaging performed by a user before starting pseudo ND filter imaging will be described with reference to FIGS.

  FIG. 8 is a flowchart of the pseudo ND shooting button processing. FIG. 9 is a flowchart of the dial rotation process during button press. FIG. 10 is a diagram for explaining a method of roughly changing the dimming rate. Here, the user can quickly select a frequently used discrete sequence value from ND2 to ND1000. Further, by selecting ND_AUTO, the camera can be set to a mode for automatically selecting the ND magnification. FIG. 11 is a diagram for explaining a method of finely changing the dimming rate. Here, FIG. 10 shows an embodiment of fine adjustment of the ND magnification when the ND 16 is selected. FIG. 12 is a flowchart of the button short-press dial rotation processing. FIG. 13 is a diagram showing an example of the dimming rate setting screen. FIG. 14 is a diagram for explaining a method of changing the ND filter type. FIG. 15 is a diagram for explaining a method of changing a target item. FIG. 16 is a flowchart of the dimming rate automatic setting process.

  The user can set the pseudo ND filter photographing by pressing the pseudo ND photographing button 3 shown in FIG. Specifically, when the pseudo ND photographing button 3 is pressed, the photographing apparatus 1 starts the pseudo ND photographing button processing shown in FIG.

  First, the photographing apparatus 1 determines whether or not the pseudo ND photographing button 3 is being pressed (step S21). If the button is being pressed, the button rotating dial processing shown in FIG. 9 is performed (step S22).

  In the dial rotation process while the button is pressed, the photographing apparatus 1 determines whether the F dial 8 or the R dial 12 has been rotated (step S31). If the F dial 8 or the R dial 12 has been rotated, the pseudo ND filter photographing Flg is set to “1”. Is set (step S32). The pseudo ND filter imaging Flg is a flag indicating whether or not the imaging apparatus 1 performs pseudo ND filter imaging. When the pseudo ND filter imaging Flg is “1”, the imaging device 1 performs the pseudo ND filter imaging, and when the pseudo ND filter imaging Flg is “0”, the imaging device 1 does not perform the pseudo ND filter imaging.

  When the flag is set, the imaging device 1 changes the dimming rate according to the rotation of the dial (steps S33 to S35). First, the imaging device 1 determines whether the rotated dial is the F dial 8 or the R dial 12 (step S33). If the rotated dial is the R dial 12, the dimming rate setting unit 51 discretely changes the dimming rate roughly as shown in FIG. 10 (step S34). On the other hand, if the rotated dial is the F dial 8, the dimming rate setting unit 51 finely changes the dimming rate, for example, so that the ND magnification changes by one as shown in FIG. 11 (step S35). ). When the dimming rate is finely changed, the upper limit and the lower limit of the dimming rate (ND magnification) may be limited as shown in FIG. The changed ND magnification is reflected on the mark 202 on the shooting standby screen shown in FIGS. 5, 6, and 7.

  As described above, in the imaging device 1, the user can manually set the dimming rate by operating the dial on the imaging device 1 (imaging standby screen).

  If it is determined that the pseudo ND shooting button 3 is short-pressed (step S23), the imaging device 1 performs a button short-press dial rotation process shown in FIG. 12 (step S24).

  In the button short-press dial rotation process, the imaging device 1 determines whether or not the pseudo ND filter imaging Flg is “1” (step S41). If it is determined that the pseudo ND filter imaging Flg is not “1”, the imaging device 1 sets “1” to the pseudo ND filter imaging Flg (step S47), and ends the button short-press dial rotation processing.

  If it is determined that the pseudo ND filter imaging Flg is “1”, the imaging device 1 displays a dimming rate setting screen (step S42). The dimming rate setting screen is, for example, a screen in which a dimming rate setting wizard 210 is superimposed on a screen displaying a live view image as shown in FIG. In the dimming rate setting wizard 210, for example, the type of the pseudo ND filter (item I1) and the ND magnification (items I2 to I6) can be changed.

  Thereafter, the imaging device 1 determines whether the F dial 8 or the R dial 12 has been rotated (step S43). Then, when it is determined that the rotated dial is the R dial 12, the photographing apparatus 1 changes the setting content of the item (hereinafter referred to as the target item) currently selected by the dimming rate setting wizard 210 (step S44). . In the example of FIG. 13, since the item I1 for designating the type of the pseudo ND filter is selected, when the R dial 12 is rotated, as shown in FIG. 14, the types of the pseudo ND filter are "half" and "normal". Switch between. Pseudo ND filter imaging using a normal type pseudo ND filter applies the same dimming rate to all pixels, whereas pseudo ND filter imaging using a half type pseudo ND filter requires each pixel line Different dimming rates are used. The half type will be described later in detail.

  If the item I2 for designating the ND magnification is selected, when the R dial 12 is rotated, discrete series values of the ND magnification (that is, the dimming rate) are switched as shown in FIG. If any of the items I3 to I6 for designating the ND magnification is selected, when the R dial 12 is rotated, the content changes by one from "0" to "9". Thereby, as shown in FIG. 11, the ND magnification can be finely changed.

  If it is determined in step S43 that the rotated dial is the F dial 8 in step S43, as shown in FIG. 15, the imaging device 1 changes the target items of the dimming rate setting wizard 210 (step S45).

  When the setting content or the target item is changed, the photographing apparatus 1 repeats the processing from step S43 to step S45 until an instruction to end the dimming rate setting is input (step S46 YES).

  As described above, in the imaging apparatus 1, the user can manually set the ND filter type and the ND magnification (dimming rate) on the dimming rate setting wizard 210.

  If it is determined that the press of the pseudo ND shooting button 3 is a long press (step S23), the imaging device 1 sets “0” to the pseudo ND filter Flg, and the imaging device 1 ends the pseudo ND filter imaging. Thus, the setting of the imaging device 1 is changed.

  If it is determined that the depression of the pseudo ND photography button 3 is a double click (step S23), the photographing apparatus 1 performs a dimming rate automatic setting process shown in FIG. 16 (step S26).

  In the automatic dimming rate setting process, first, the photographing apparatus 1 analyzes a live view image (step S51) and determines a photographing scene (step S52).

  If the imaging device 1 determines that the subject is a waterfall or a mountain stream, it sets the dimming rate so that the third exposure time is, for example, 30 seconds (step S53). Thereafter, the image capturing apparatus 1 displays the words "waterfall / mountain stream like silk thread" on the display unit 2 for 3 seconds (step S54), and ends the automatic dimming rate setting process.

  When determining that the subject is on the water surface, the imaging device 1 calculates a fluctuation cycle of the brightness of the water surface from the live view image, and sets the third light exposure rate to be, for example, twice as large as the fluctuation cycle calculated. Is set (step S55). After that, the image capturing apparatus 1 displays the phrase “water surface like a mirror surface” on the display unit 3 for 3 seconds (step S56), and ends the automatic dimming rate setting process.

  When determining that the subject is fireworks, the imaging device 1 sets the dimming rate so that the relationship of, for example, “ISO sensitivity / 100 = 4” is satisfied (step S57). After that, the image capturing apparatus 1 displays the words "Let's prevent color loss of fireworks" on the display unit 2 for 3 seconds (step S58), and ends the automatic dimming rate setting process.

  When determining that the subject is a busy street, the imaging device 1 sets the dimming rate so that the third exposure time is 2 seconds, for example (step S59). After that, the image capturing apparatus 1 displays the words “Let's give a busy atmosphere” for 3 seconds on the display unit 2 (Step S60), and ends the automatic dimming rate setting process.

  When the imaging device 1 determines that the subject is a drifting cloud, the imaging device 1 calculates the speed of the flow of the cloud from the live view image. The dimming rate is set so as to reach the time (step S61). After that, the image capturing apparatus 1 displays the words “Let the atmosphere of a drifting cloud” appear on the display unit 3 for 3 seconds (step S62), and ends the automatic dimming rate setting process.

  As described above, in the photographing apparatus 1, when the user desires, instead of manually setting the dimming rate, the photographing apparatus 1 automatically determines the photographing scene and automatically sets an appropriate dimming rate. Can be set with.

  FIG. 17 is a flowchart of a photographing process performed by the photographing device 1. FIG. 18 is a flowchart of the preprocessing. FIG. 19 is a modified example of the flowchart of the preprocessing. FIG. 20 is a flowchart of the exposure time setting process. FIG. 21 is a flowchart of the manual ND exposure time setting process. FIG. 22 is a flowchart of the continuity calculation process. FIG. 23 is a modification of the flowchart of the continuity calculation process. FIG. 24 is a diagram illustrating an example of a warning display regarding continuity. FIG. 25 is a flowchart of the reproducibility calculation process. FIG. 26 is a modified example of the flowchart of the reproducibility calculation process. FIG. 27 is a modified example of the flowchart of the manual ND exposure time setting process. FIG. 28 is a flowchart of the automatic ND exposure time setting process. FIG. 29 is a flowchart of the live simulation process. FIG. 30 is a flowchart of the pseudo ND filter photographing process. FIG. 31 is a flowchart of the multi-shooting process. Hereinafter, the simulation of the pseudo ND filter imaging and the pseudo ND filter imaging will be described in detail with reference to FIGS.

  When the photographing process shown in FIG. 17 is started, the photographing apparatus 1 first determines whether or not the pseudo ND filter photographing Flg is “1” (step S71). Here, when it is determined that the pseudo ND filter imaging Flg is not “1”, the imaging apparatus 1 performs a normal imaging process (step S78).

  When it is determined that the pseudo ND filter imaging Flg is “1”, the imaging device 1 performs the pre-processing illustrated in FIG. 18 (Step S72). Note that the pre-processing is a preparation process for appropriately performing the pseudo ND filter imaging. The pre-processing illustrated in FIG. 18 is performed when inappropriate settings are made for the pseudo ND filter imaging. This is a process for prohibiting the pseudo ND filter imaging and performing the normal process of step S78.

  In the pre-processing shown in FIG. 18, the imaging device 1 first determines an imaging mode (step S81). When the photographing mode is a predetermined mode that is not appropriate for the pseudo ND filter photographing, the photographing apparatus 1 performs the normal processing without performing the pseudo ND filter photographing (step S78). The predetermined modes that are not appropriate for the pseudo ND filter shooting are, for example, an automatic exposure shooting mode, a BULB shooting mode, a flash shooting mode, and a moving image shooting mode.

  The automatic exposure shooting mode is a shooting mode in which at least one of the shutter speed and the aperture is determined according to the brightness of the subject, and includes a P mode, an A mode, an S mode, and the like. In photographing using an ND filter, there are usually a target aperture value (depth of field) and a shutter speed. Therefore, the automatic exposure photographing mode in which at least one of these is automatically determined is a pseudo-ND filter photographing. Not the proper shooting mode.

  The BULB shooting mode has an indefinite exposure time before shooting, and is not suitable for pseudo ND filter shooting in that point. Further, in the flash photography mode, it is difficult to reduce the amount of light incident by the flash according to the designated dimming rate in terms of the resolution of the flash emission control unit, which is suitable for pseudo ND filter photography. Absent. Since the continuity of exposure between frames of a moving image is regarded as important, the moving image shooting mode is not suitable for pseudo ND filter shooting.

  If it is determined that the shooting mode is other than the predetermined mode, the shooting device 1 determines the shutter mode (Step S82). When the shutter mode is the mechanical shutter mode, the imaging device 1 performs the normal processing without performing the pseudo ND filter imaging.

  When a mechanical shutter is used, a non-exposure period occurs in a shooting frame period due to a shutter charge and an imaging reset. For this reason, continuity is not ensured between the frame images, and the motion of the subject is reproduced discontinuously. Since the discontinuity can be a factor that hinders the normal performance of the slow shutter effect, the mechanical shutter is not suitable for pseudo ND filter imaging.

  If it is determined that the shutter mode is the electronic shutter mode, the imaging device 1 updates the ISO sensitivity (step S83), and ends the pre-processing. Here, it is desirable that the photographing apparatus 1 sets, for example, the ISO sensitivity to a lower ISO sensitivity than that in the normal photographing. The sensitivity may be limited to the lowest ISO sensitivity that can be set by the photographing apparatus 1, or may be limited to the lowest ISO sensitivity excluding the extended ISO sensitivity. Further, the ISO sensitivity setting range including the extended ISO sensitivity may be limited in consideration of the dynamic range.

  As described above, in step S83, the ISO sensitivity is limited by changing the ISO sensitivity for normal imaging to the ISO sensitivity for pseudo ND filter imaging. As a result, it is not only meaningless to set the ND magnification to a high value with a high ISO sensitivity, but rather, a harmful setting action in image quality can be prevented.

  As described above, by performing the pre-processing illustrated in FIG. 18, when improper settings are set for the pseudo ND filter imaging, the imaging apparatus 1 performs the normal processing of step S78. This makes it possible to prohibit pseudo ND filter imaging with inappropriate settings.

  Note that the imaging device 1 may perform the pre-processing illustrated in FIG. 19 instead of the pre-processing illustrated in FIG. The pre-processing shown in FIG. 19 is a process of changing the setting suitable for the pseudo ND filter imaging when the setting inappropriate for the pseudo ND filter imaging is made.

  In the preprocessing shown in FIG. 19, the photographing apparatus 1 first determines the exposure mode (step S91), and when the exposure mode is the automatic exposure mode, sets the exposure mode to the manual exposure mode (step S92). .

  Further, the photographing apparatus 1 determines the shutter mode (Step S93), and when the shutter mode is the mechanical shutter mode, sets the shutter mode to the electronic shutter mode (Step S94).

  Finally, the photographing apparatus 1 updates the ISO sensitivity (step S95), and ends the pre-processing. Note that the processing in step S95 is the same as the processing in step S83.

  As described above, the imaging apparatus 1 performs the pre-processing shown in FIG. 19 instead of the pre-processing shown in FIG. It is desirable that the setting be automatically changed to an appropriate setting in order to reduce the number of rework steps. Also in this case, similarly to the case where the pre-processing shown in FIG. 18 is performed, pseudo ND filter imaging with inappropriate settings can be prohibited by automatic setting change.

  When the pre-processing is completed, the imaging device 1 performs an exposure time setting process shown in FIG. 20 (Step S73). In the exposure time setting process shown in FIG. 20, the imaging device 1 first determines whether or not the automatic ND setting has been performed (step S101). Note that the automatic ND setting refers to a setting in which the image capturing apparatus 1 automatically determines the ND magnification (that is, the dimming rate).

  If the automatic ND setting has not been performed, the imaging device 1 performs a manual ND exposure time setting process shown in FIG. 21 (step S102). If the automatic ND setting has been made, the image capturing apparatus 1 performs an automatic ND exposure time setting process shown in FIG. 28 (step S103).

  When the manual ND exposure time setting process shown in FIG. 21 is started, the photographing apparatus 1 first sets a second exposure time (step S111), and further determines an exposure mode (step S112). Here, the second exposure time is the reciprocal of the frame rate of the live view. The frame rate of the live view usually takes a value from 15 fps to 120 fps depending on the brightness.

  When the exposure mode is the manual exposure mode, the imaging device 1 sets the third exposure time to the time specified by the user (step S113), and sets the first exposure time to the third exposure time set in step S113. The time calculated by multiplying the three exposure times by the extinction ratio is set (step S114).

  On the other hand, when the exposure mode is the automatic exposure mode, the imaging device 1 performs automatic exposure control to estimate the exposure time (step S115). Thereafter, the photographing apparatus 1 sets the exposure time estimated in step S115 as the first exposure time (step S116), and divides the third exposure time by dividing the first exposure time set in step S116 by the dimming rate. Is set (step S117).

  When the first exposure time and the third exposure time are set, the photographing apparatus 1 sets the third exposure time as the display exposure time (step S118), and then performs the continuity calculation processing shown in FIG. 22 (step S118). Step S119). The display exposure time is an exposure time displayed on the display unit 2, and is used, for example, for generating the mark 200 shown in FIGS.

  The continuity calculation process is a process for ensuring that the slow shutter effect is properly exerted in the pseudo ND filter shooting. If the first exposure time is too short with respect to the frame rate of the main image reading control for the still image, the flow indicating the motion of the subject that should appear in the image due to the slow shutter effect is cut off. More specifically, the first exposure time is longer than the time corresponding to the reciprocal of the maximum frame rate of the main image reading control for the still image (that is, 1 / maximum frame rate, also referred to as maximum frame rate time). If it is short, the flow appearing in the image may be cut off. Here, the main exposure reading frame rate is a frame rate in a control in which the image capturing apparatus 1 reads out all pixels, and is slower as the image pickup device is larger. For a large image sensor for one eye, a value of about 20 fps to about 60 fps is usually used.

  Therefore, in the continuity calculation process, the photographing apparatus 1 determines whether the first exposure time is equal to or longer than the time corresponding to the reciprocal of the maximum frame rate of the main image reading control for the still image (step S121). If one exposure time is shorter than the time corresponding to the reciprocal of the maximum frame rate for a still image, the first exposure time and the third exposure time are reset (steps S122 and S123). Specifically, the imaging device 1 sets a time corresponding to the reciprocal of the maximum frame rate of the main image reading control for the still image to the first exposure time (step S122), and sets the first exposure time to the third exposure time. Is set by dividing by the dimming rate (step S123). Thereby, the slow shutter effect is sufficiently exhibited without the flow being cut off on the image. The first exposure time may be set to a time longer than the time corresponding to the reciprocal of the maximum frame rate of the main image reading control for the still image.

  Instead of the continuity calculation processing shown in FIG. 22, the continuity calculation processing shown in FIG. 23 may be performed. In the continuity calculation processing shown in FIG. 23, the imaging device 1 determines whether the first exposure time is equal to or longer than the time corresponding to the reciprocal of the maximum frame rate for a still image (step S131), and Is less than the time corresponding to the reciprocal of the maximum frame rate of the main image reading control for the still image, a warning is displayed (step S132).

  The method of displaying the warning is not particularly limited, but as shown in FIG. 24, the mark 202 indicating the ND magnification and the mark 200 indicating the third exposure time blink at, for example, 2 Hz, so that the motion of the subject appearing in the image is performed. May be notified to the user that the flow indicating is broken. Thus, it is possible to prompt the user to adjust the first exposure time voluntarily.

  When the continuity calculation processing shown in FIG. 22 or FIG. 23 ends, the imaging device 1 performs the reproducibility calculation processing shown in FIG. 25 (step S120).

  The reproducibility calculation process is a process for ensuring that the slow shutter effect in the pseudo ND filter imaging is appropriately reproduced in the simulation of the pseudo ND filter imaging. If the frame rate for displaying the live view image is higher than the maximum frame rate for main exposure reading for recording the still image, the slow shutter effect that can be confirmed in the live view image is not always obtained in the still image. Further, even when the second exposure time for displaying the live view image is shorter than the live view frame rate time, the slow shutter effect that can be confirmed in the live view image is not always obtained in the still image.

  Therefore, in the reproducibility calculation processing, the photographing apparatus 1 determines whether the second exposure time is less than the live view frame rate time (step S141), and determines that the second exposure time is less than the live view frame rate time. Next, the live view frame rate time is set as the second exposure time (step S142). As a result, it is possible to prevent the simulation reproducibility of the slow shutter effect from being lowered due to the difference between the second exposure time and the live view frame rate time. Note that the live view frame rate time is a time corresponding to the reciprocal of the frame rate for displaying a live view image.

  Note that the reproducibility calculation processing shown in FIG. 26 may be performed instead of the reproducibility calculation processing shown in FIG. In the reproducibility calculation process shown in FIG. 26, the imaging device 1 determines whether the second exposure time is less than the live view frame rate time (step S151), and determines that the second exposure time is less than the live view frame rate time. If there is, a warning is displayed (step S152). This allows the user to notice that there is a problem in the reproducibility of the slow shutter effect and the overexposure prevention effect of the live view.

  In the manual ND exposure time setting process shown in FIG. 21 described above, an example is shown in which the user specifies the third exposure time when the exposure mode is the manual exposure mode. Instead of the manual ND exposure time setting process shown in FIG. 21, a manual ND exposure time setting process shown in FIG. 27 may be performed. In the manual ND exposure time setting process shown in FIG. 27, when the exposure mode is the manual exposure mode, the imaging device 1 sets the first exposure time to the time designated by the user (step S163). The time calculated by dividing the first exposure time set in step S163 by the dimming rate is set to the three exposure times (step S164). Other processes are the same as the manual ND exposure time setting process shown in FIG. Specifically, the processing of steps S161 and S162 is the same as the processing of steps S111 and S112 shown in FIG. The processing from step S165 to step S170 is the same as the processing from step S115 to step S120 shown in FIG.

  By performing the manual ND exposure time setting processing shown in FIGS. 21 and 27, the imaging apparatus 1 can perform the first exposure time, the second exposure time, and the third exposure time based on the manually set dimming rate. Can be set appropriately.

  On the other hand, when the automatic ND exposure time setting process shown in FIG. 28 is started, the photographing apparatus 1 first sets a second exposure time (step S171), and further performs automatic exposure control to perform exposure. The time is estimated (step S172).

  Thereafter, the imaging device 1 determines the photometry mode (Step S173). If the metering mode is other than the evaluation metering mode (for example, spot metering mode, center-weighted metering mode, etc.), the exposure time estimated in step S172 is set as the first exposure time without performing the saturation point detection. (Step S178).

  On the other hand, when the photometry mode is the evaluation photometry mode, the imaging device 1 performs the saturation point detection (step S174). If a saturation point exists (step S175 YES), the imaging device 1 recalculates the exposure time (step S176), and sets the first exposure time to the recalculated exposure time in step S176 (step S177). ). If no saturation point exists (step S175 NO), the imaging device 1 sets the first exposure time to the exposure time estimated in step S172 (step S178).

  When the first exposure time is set, the imaging device 1 determines an exposure mode (Step S179). If the exposure mode is the automatic exposure mode, the imaging device 1 sets the third exposure time to the same time as the first exposure time set in step S177 or step S178 (step S182). On the other hand, when the exposure mode is the manual exposure mode, the imaging device 1 sets the third exposure time to the time specified by the user (step S180). Thereafter, the first exposure time is compared with the third exposure time (step S181). If the first exposure time is long, the first exposure time is set to the third exposure time in order to avoid a small ND magnification. The same time as the exposure time is set (step S182).

  When the first exposure time and the third exposure time are set, the imaging device 1 sets the third exposure time as the display exposure time (step S183). Finally, the imaging device 1 sets the first exposure time and the third exposure time. The extinction ratio is set based on the third exposure time (step S184), and the automatic ND exposure time setting process ends. Note that the dimming rate is calculated by dividing the first exposure time by the third exposure time.

  By performing the automatic ND exposure time setting process shown in FIG. 28, the photographing apparatus 1 sets the first exposure time, the second exposure time, and the third exposure time without manually setting the dimming rate. can do.

  When the exposure time setting process (step S73 in FIG. 17) ends, the imaging device 1 determines whether or not the LV addition and synthesis Flg is “1” (step S74). The LV addition synthesis Flg is a flag indicating whether or not the imaging device 1 performs a simulation of pseudo ND filter imaging. The setting of the LV addition synthesis Flg can be manually performed by the user on the setting screen. Thereby, the user can instruct the start and stop of the live view simulation of the pseudo ND filter imaging at an arbitrary timing on the imaging standby screen. Further, the LV countable composition Flg is changed in accordance with the operation of changing the imaging conditions of the pseudo ND filter imaging, and the simulation is stopped, reset, and restarted.

  If it is determined that the LV-added composite Flg is "1", the imaging device 1 performs the live simulation process shown in FIG. 29 (step S75), and if it is determined that the LV-added composite Flg is "0". The imaging device 1 performs a normal live view image display process (step S76).

  When the live simulation process shown in FIG. 29 is started, the photographing apparatus 1 first determines an ND filter type (step S191). If the ND filter type is half, the imaging device 1 performs a half ND filter live view image display process (step S208).

  On the other hand, when the ND filter type is normal, the imaging device 1 acquires one frame of image data (second image data) F for a live view image (step S192). Here, the imaging unit 20 acquires image data at the second exposure time T2. Next, the imaging device 1 adds and synthesizes the acquired image data F to generate synthesized image data (step S193). Here, the composite image data F1 and the composite image data F2 are generated. After the addition and synthesis, the imaging device 1 updates the counter (Step S194). Here, the counter K1 for the composite image data F1 and the counter K2 for the composite image data F2 are updated.

  Next, the imaging device 1 determines whether or not the counter K2 has reached a predetermined threshold value KTH (step S195). The threshold KTH is a threshold that controls the update frequency of the live view image under specific conditions. The threshold value KTH may be calculated from the live view image display frame rate such that the update of the live view image is about 0.5 to 1 second. If the counter K2 is equal to the predetermined threshold KTH, the photographing apparatus 1 stores the composite image data F2 in a FIFO (First In, First Out) queue, and resets the composite image data F2 and the counter K2 (step S196). As a result, live view countable image data F2 of about 0.5 to 1 second is sequentially queued in the FIFO queue. Countable image data for each frame of the live view is accumulated in the composite image data F2.

  Further, the photographing apparatus 1 determines whether or not the total exposure time (second total exposure time) TT for obtaining the composite image data F1 has reached the third exposure time T3 (Step S197). When the total exposure time TT has not reached the third exposure time T3 (step S197 YES), the imaging device 1 updates the progress display displayed on the display unit 2 (step S202). The progress display is, for example, a mark 201 shown in FIG. 5 and a mark 201a shown in FIGS. 6 and 7. The imaging device 1 generates, for example, the mark 201 illustrated in FIG. 5 based on the total exposure time TT and the third exposure time T3, and displays the mark 201 on the display unit 2. Thus, the mark 201 is updated as needed until the total exposure time TT reaches the third exposure time T3.

  Thereafter, the imaging device 1 calculates the gain (second gain) G1 using the above-described equation (2) (step S203). Further, the imaging device 1 generates live view image data by applying the calculated gain G1 to the composite image data F1 (step S204), and updates and displays the live view image based on the live view image data (step S204). S205). As described above, the countable composite image data F1 is displayed and updated on the live view at the frame rate of the live view.

  On the other hand, when the total exposure time TT has reached the third exposure time T3 (step S197 NO), the imaging device 1 determines whether the total exposure time TT has reached the third exposure time T3 + the threshold time TTH. (Step S198). Here, the threshold time TTH is an exposure time required to acquire the threshold KTH image data F. That is, the threshold time TTH is calculated by the second exposure time T2 × threshold KTH.

  When the total exposure time TT has not reached the third exposure time T3 + the threshold time TTH, the imaging device 1 performs the process of step S206 without updating the live view image. On the other hand, when the total exposure time TT has reached the third exposure time T3 + the threshold time TTH, the image capturing apparatus 1 extracts the data FO from the FIFO queue (step S199) and subtracts the data FO from the composite image data F1. The image data F1 is updated (step S200). This makes it possible to reflect the latest image data while maintaining the slow shutter effect of the exposure time T3. Further, the imaging device 1 updates the counter K1 by subtracting the threshold value KTH from the counter K1. The data FO is the oldest data stored in the FIFO queue.

  Thereafter, the photographing apparatus 1 calculates the gain G1 as in the case where the total exposure time TT has not reached the third exposure time T3 (step S203), and applies the gain G1 to the composite image data F1 to perform live processing. View image data is generated (step S204), and the live view image is updated and displayed based on the live view image data (step S205). In the calculation of the gain G1 in step S203, the total exposure time TT is recalculated in consideration of the subtraction process in step 200. As described above, after the total exposure time TT reaches the third exposure time T3, the countable composite image data F1 is updated and displayed on the live view at an interval of 0.5 seconds to 1 second with a reduced update frequency.

  Finally, the photographing apparatus 1 determines whether or not a photographing instruction for pseudo ND filter photographing has been input (step S206). If not, the process returns to step S191 to repeat the processing.

  By performing the live simulation shown in FIG. 29, the imaging device 1 can display a live view image obtained by simulating the pseudo ND filter imaging. In particular, since the display is updated at the frame rate of the live view image until the total exposure time TT reaches the exposure time T3, the user can check the slow shutter effect according to the total exposure time in real time. . After the total exposure time TT has reached the exposure time T3, the user has already confirmed the slow shutter effect corresponding to the exposure time T3. For this reason, the consumption of the buffer memory is suppressed by suppressing the update frequency. Specifically, by updating the display of the live view image every threshold time TTH, the latest subject information can be reflected on the display. With the above configuration, a large-capacity buffer memory is not required, and the ND magnification exceeds 400 even with the normal buffer memory capacity of a single-lens camera. -It will be possible to conduct a session.

  When the live simulation or the normal live view image display processing in step S75 is completed in response to the input of the imaging instruction for the pseudo ND filter imaging, the imaging apparatus 1 performs the pseudo ND filter imaging processing shown in FIG. 30 (step S77).

  When the pseudo ND filter photographing process shown in FIG. 30 is started, the photographing apparatus 1 reads out all the pixels at the frame rate by the main exposure readout control, and converts the image data (first image data) F for a still image into one frame. A minute is acquired (step S211). Here, the imaging unit 20 acquires image data at the first exposure time T1. Next, the imaging device 1 adds and synthesizes the acquired image data F to generate synthesized image data (step S212). Here, the composite image data Y1 is generated. Further, the photographing apparatus 1 performs the multi-photographing process shown in FIG. 31 (step S213), and thereafter, the total exposure time (first total exposure time) YT for obtaining the composite image data Y1 reaches the third exposure time T3. Until (YES in step S214), the main exposure readout control is seamlessly and continuously repeated, and the processes in steps S211 to S213 are repeated. The multi-shooting process will be described later.

  When the total exposure time YT reaches the third exposure time T3, the imaging device 1 calculates the gain (first gain) GY1 using the above-described equation (1) (step S215). Further, the imaging device 1 generates still image data by applying the calculated gain GY1 to the composite image data Y1 (step S216), and records the generated still image data (step S217).

  By performing the pseudo ND filter photographing shown in FIG. 30, the photographing apparatus 1 can simulate photographing using the ND filter without using the ND filter and obtain a still image having a slow shutter effect. Further, by confirming the slow shutter effect in advance by the live simulation shown in FIG. 29, the slow shutter effect as intended by the user can be obtained by the pseudo ND filter photographing shown in FIG.

  The multi-shooting process shown in FIG. 31 is a process for recording not only the still image data corresponding to the exposure time T3 but also the still image data corresponding to a halfway time before the exposure time T3. Specifically, when the multi-shooting setting is set to ON (step S221 YES), the photographing apparatus 1 calculates a recording timing based on a preset number of recordings (step S222). Then, when the total exposure time YT matches the recording timing (step S223 YES), the imaging device 1 calculates the gain GY1 (step S224), applies the gain GY1 to the composite image data Y1, and converts the still image data. The still image data is generated (step S225), and the generated still image data is recorded (step S226). Thus, in addition to the still image data corresponding to the exposure time T3, still image data having a slow shutter effect different from the still image data corresponding to the exposure time T3 can be obtained.

  Although the case where the ND filter type is normal has been described above, the pseudo ND filter imaging can be performed even when the ND filter type is half. Hereinafter, the pseudo ND filter imaging when the ND filter type is half will be described with reference to FIGS. 32 to 35. FIG. 32 is a diagram illustrating an example of a still image. FIG. 33 is a diagram for explaining setting of a half-type pseudo ND filter. FIG. 34 is a diagram for describing a pixel line of a still image. FIG. 35 is a diagram illustrating an example of the pseudo ND filter table.

  For example, when photographing a landscape as shown in FIG. 32, it may be desired to make the ND magnification different between the sky portion and the mountain portion. Half-type pseudo ND filter imaging is suitable for such a case.

  As shown in FIG. 33, on the screen for setting the half-type pseudo ND filter, the ND magnification to be applied to each pixel can be set using the upper boundary line 301 and the lower boundary line 302. For example, ND100 is set as the ND magnification for the upper boundary line 301, and the upper boundary line 301 is moved to the vicinity of the boundary between the sky and the mountain using the button 301a. As a result, ND100 is set for the upper boundary line 301 and the pixel lines above it. In addition, ND2 is set as the ND magnification for the lower boundary line 302, and the lower boundary line 302 is moved to a desired position using the button 302a. As a result, ND2 is set for the lower boundary line 302 and the pixel lines below it. Further, an ND magnification between the upper limit ND100 and the lower limit ND2 is set for a pixel line between the upper limit boundary line 301 and the lower limit boundary line 302. For example, an ND magnification calculated by linearly interpolating ND100 and ND2 may be set for each pixel line between the upper boundary line 301 and the lower boundary line 302. Note that the same ND magnification may be set in units of several pixel lines, and the ND magnification may be changed stepwise from the upper limit to the lower limit. The ND magnification between the upper boundary line 301 and the lower boundary line 302 is not limited to linear interpolation, and may be interpolated by a higher-order function such as a quadratic function.

  By performing the above operation, the ND magnification is set for each of the pixel lines LINE (1) to LINE (N) shown in FIG. 34 and recorded in the table 310 shown in FIG. In the half-type pseudo ND filter imaging, the ND magnification (dimming rate) is set for each pixel line by referring to the table 310, and each pixel is exposed for an exposure time according to the ND magnification.

  The embodiments described above show specific examples for facilitating the understanding of the invention, and the embodiments of the invention are not limited to these. The imaging device, the imaging method, and the program can be variously modified and changed without departing from the scope of the claims.

  In FIG. 3, the exposure time setting unit 50 having the dimming rate setting unit 51 is illustrated, but the imaging apparatus 1 may include the exposure time setting unit 50a illustrated in FIG. 36 instead of the exposure time setting unit 50. Good. The exposure time setting unit 50a is different from the exposure time setting unit 50 in that the exposure time setting unit 50a has a first exposure time setting unit 51a and a third exposure time setting unit 51b instead of the dimming rate setting unit 51. The first exposure time setting unit 51a sets the first exposure time specified by the user operating the operation unit 38, and the third exposure time setting unit 51b sets the first exposure time by the user operating the operation unit 38. The designated third exposure time is set. The exposure time setting unit 50a calculates and sets the light attenuation rate from the first exposure time set by the first exposure time setting unit 51a and the third exposure time set by the third exposure time setting unit 51b.

  When the photographing apparatus 1 includes the exposure time setting unit 50a instead of the exposure time setting unit 50, the photographing device 1 performs a button short press dial rotation process illustrated in FIG. 37 instead of the button short press dial rotation process illustrated in FIG. .

  In the button short-press dial rotation processing illustrated in FIG. 37, the imaging device 1 determines whether or not the pseudo ND filter imaging Flg is “1” (step S231). If it is determined that the pseudo ND filter imaging Flg is not “1”, the imaging device 1 sets “1” to the pseudo ND filter imaging Flg (step S238), and ends the button short-press dial rotation processing.

  When it is determined that the pseudo ND filter imaging Flg is “1”, the imaging device 1 displays a twin shutter speed setting screen (step S42). The twin shutter speed setting screen is, for example, a screen in which a twin shutter speed setting wizard 220 is superimposed on a screen displaying a live view image as shown in FIG. In the twin shutter speed setting wizard 220, for example, the first exposure time for determining the brightness of the image and the third exposure time for determining the slow shutter effect can be changed. FIG. 38 shows an example in which the first exposure time is set to 1/60 s and the third exposure time is set to 10 seconds.

  Thereafter, the imaging device 1 determines whether the F dial 8 or the R dial 12 has been rotated (Step S234). Then, when it is determined that the rotated dial is the R dial 12, the imaging device 1 changes the third exposure time displayed on the twin shutter speed setting wizard 220 according to the rotation amount (step S235). Further, when it is determined that the rotated dial is the F dial 8, the imaging device 1 changes the first exposure time indicated by the twin shutter speed setting wizard 220 according to the rotation amount (step S236). In steps S235 and S236, the ND magnification is recalculated and the display of the ND magnification is updated in accordance with the change in the first exposure time or the third exposure time.

  The photographing apparatus 1 repeats the processing from step S234 to step S236 until an instruction to end the shutter speed setting is input (step S237YES).

  As described above, even when the image capturing apparatus 1 includes the exposure time setting unit 50a instead of the exposure time setting unit 50, the imaging apparatus 1 can simulate the pseudo ND filter imaging before imaging to perform live view display.

  In FIG. 3, the exposure time setting unit 50 having the dimming rate setting unit 51 is illustrated, but the imaging apparatus 1 may have the exposure time setting unit 50b illustrated in FIG. Good. The exposure time setting unit 50b is different from the exposure time setting unit 50 in that an exposure combined number setting unit 51c is provided instead of the dimming rate setting unit 51. The added combined number setting unit 51c sets the added combined number in the pseudo ND filter shooting specified by the user operating the operation unit 38, and calculates the first exposure time and the third exposure time based on the added combined number. I do. The number of combined images is the reciprocal of the dimming rate.

  As described above, even when the exposure time setting unit 50b is provided instead of the exposure time setting unit 50, the imaging device 1 can simulate the pseudo ND filter imaging and perform live view display before imaging.

  Further, the imaging device 1 may reset the sequential addition processing of the second image data under a predetermined condition. For example, when notified of the change of the shooting setting, the second combining unit 63 resets the already generated second combined image data, and obtains the second image acquired by the imaging unit 20 after the shooting setting is changed. The data may be sequentially added and synthesized. The shooting settings include, for example, focus adjustment by operating the manual focus ring 6, magnification change by operating the magnifying button 9, and operating the zoom ring 5. The change of the photographing setting may be detected by the operation of the operation unit 38 performed by the user. When the camera shake amount equal to or more than the first threshold value is detected by the camera shake detection unit 34, the second combining unit 63 resets the already generated second combined image data, ends the processing, and sets the camera shake amount to the first shake amount. May be configured to sequentially add and synthesize only the second image data in a state smaller than the threshold value. . This prevents images with different compositions from being synthesized due to changes in the angle of view in response to disturbances or zoom changes caused by camera shake, or prevents improper simulation from continuing when images with different focus conditions from when shooting were continued. This enables a quick simulation according to a change in shooting conditions, and contributes to quick confirmation and quick redoing of the user.

REFERENCE SIGNS LIST 1 shooting device 2 display unit 3 pseudo ND shooting button 4 shooting mode dial 5 zoom ring 6 manual focus ring 7 shutter button 8 F dial 9 enlarge button 10 movie button 11 LV mode button 12 R dial 20 imaging unit 21 lens 22 aperture 23 mechanical Shutter 24 Image sensor 25 A / D converter 26 Memory 27 System controller 28 Image controller 29 Shutter controller 30 Aperture controller 31 Lens controller 32 AF processor 33 Exposure controller 34 Camera shake detector 35 Image processor 36 Power supply Unit 37 power control unit 38 operation unit 39 external memory 40 nonvolatile memory 41 flash control unit 42 flash charging unit 43 flash light emitting units 50, 50a, 50b exposure time setting unit 51 dimming rate setting unit 51a first exposure time setting unit 51b Third exposure time setting section 51c Addition / combination number setting unit 60 Image generation unit 61 First synthesis unit 62 First gain application unit 63 Second synthesis unit 64 Second gain application unit 70 Still image recording unit 80 Live view image display unit 90 Exposure time display unit 100 101 Live view image 200, 200a, 201, 201a, 202, 204a Mark 210 Dimming rate setting wizard 220 Twin shutter speed setting wizard 301 Upper boundary line 301a, 302a Button 302 Lower boundary line 310 Table

Claims (20)

An imaging unit for imaging a subject, wherein the imaging unit acquires first image data for recording a still image at a first exposure time, and acquires second image data for live view image display at a second exposure time; ,
A first combining unit that adds and combines a plurality of first image data repeatedly acquired by the imaging unit until a first total exposure time reaches a third exposure time;
A first gain application unit that generates first still image data having a first brightness by applying a first gain to the first combined image data output from the first combining unit;
A second combining unit that sequentially adds and combines the second image data acquired by the imaging unit;
A second gain application unit configured to generate a first live view image data having the first brightness by applying a second gain to the second synthesized image data sequentially output from the second synthesis unit; The second gain application unit, wherein the second gain is applied each time the second combined image data is output from the second combination unit;
A display unit that updates and displays a first live view image at a frame rate for the live view image display in the imaging unit based on the first live view image data generated by the second gain application unit; An imaging device comprising: The photographing apparatus according to claim 1, further comprising:
The first exposure time and the third exposure time are set based on the dimming rate set for the still image recording, and the second exposure time is set based on a frame rate for displaying the live view image. An exposure time setting unit for
The exposure time setting unit calculates the other of the first exposure time and the third exposure time based on the dimming rate and one of the first exposure time and the third exposure time. Characteristic imaging device. The photographing apparatus according to claim 2,
The exposure time setting unit may calculate the other of the first exposure time and the third exposure time such that a ratio between the first exposure time and the third exposure time matches the dimming rate. Characteristic imaging device. The photographing apparatus according to claim 2 or 3,
The first exposure time is an exposure time estimated by the image capturing apparatus performing automatic exposure control,
The photographing apparatus according to claim 1, wherein the exposure time setting unit calculates the third exposure time by dividing the first exposure time by the dimming rate. The photographing apparatus according to claim 2 or 3,
The photographing apparatus, wherein the exposure time setting unit calculates the first exposure time by multiplying the third exposure time manually set in the photographing apparatus by the dimming rate. The photographing apparatus according to any one of claims 2 to 5, further comprising:
An operation unit that receives a user operation for specifying the dimming rate;
An imaging apparatus, comprising: a dimming rate setting unit configured to set the dimming rate specified by the user. The photographing apparatus according to any one of claims 2 to 6,
The exposure time setting unit,
Determining whether the first exposure time is equal to or longer than a time corresponding to a reciprocal of a maximum frame rate of the main exposure readout for recording the still image in the imaging unit,
When it is determined that the first exposure time is less than the time corresponding to the reciprocal of the maximum frame rate, the first exposure time is changed to a time longer than the time corresponding to the reciprocal of the maximum frame rate. Photographing device. The photographing apparatus according to any one of claims 2 to 6,
The exposure time setting unit determines whether the first exposure time is equal to or longer than a time corresponding to a reciprocal of a maximum frame rate of the main image reading for the still image recording in the imaging unit,
The image capturing apparatus according to claim 1, wherein the display unit displays a warning when the exposure time setting unit determines that the first exposure time is less than a time corresponding to a reciprocal of the maximum frame rate. The photographing apparatus according to any one of claims 2 to 6,
The exposure time setting unit,
Determine whether the second exposure time is less than the time corresponding to the reciprocal of the frame rate for the live view image display,
If it is determined that the second exposure time is less than the time corresponding to the reciprocal of the live view image display frame rate, the second exposure time corresponds to the reciprocal of the live view image display frame rate. An imaging device characterized by changing to time. The photographing apparatus according to any one of claims 2 to 6,
The exposure time setting unit determines whether the second exposure time is less than a time corresponding to a reciprocal of a frame rate for the live view image display,
The display unit displays a warning when the second exposure time is determined by the exposure time setting unit to be less than a time corresponding to a reciprocal of a frame rate for the live view image display, Shooting device. The imaging device according to any one of claims 1 to 10,
An imaging apparatus, wherein, when notified of a change in shooting setting, the second combining unit sequentially adds and combines the second image data acquired by the imaging unit after the shooting setting is changed. The imaging device according to any one of claims 1 to 11, further comprising:
A camera shake detection unit that detects a camera shake amount of the imaging device,
When the camera shake amount equal to or more than the first threshold is detected by the camera shake detection unit, the second synthesis unit resets and ends, and the image pickup unit acquires the camera shake amount at the camera shake amount smaller than the first threshold. An imaging device, wherein the second image data is sequentially countably combined. The photographing apparatus according to claim 1, further comprising:
An exposure time setting unit configured to set the first exposure time and the third exposure time based on the number of combined images set for recording the still image,
The exposure time setting unit may calculate the other of the first exposure time and the third exposure time based on the added combined number and one of the first exposure time and the third exposure time. Characteristic imaging device. The photographing apparatus according to claim 1, further comprising:
A photometric unit for detecting the subject brightness,
An image capturing apparatus, comprising: an exposure time setting unit that sets the first exposure time, the second exposure time, and the third exposure time based on a subject luminance detected by the photometry unit. The imaging device according to any one of claims 1 to 14,
The photographing device, wherein the display unit displays the third exposure time. The imaging device according to any one of claims 1 to 15,
The photographing apparatus, wherein the display unit displays the first exposure time and the third exposure time. The imaging device according to any one of claims 1 to 16,
The apparatus according to claim 1, wherein the display unit displays a ratio of an exposure time corresponding to the second combined image data to the third exposure time. The imaging device according to any one of claims 1 to 17,
The first exposure time determines the first brightness,
The imaging device according to claim 1, wherein the third exposure time determines a tracking time of the movement of the subject. First combined image data is generated by adding and combining a plurality of first image data repeatedly acquired until the first total exposure time reaches a third exposure time, wherein each of the plurality of first image data is , Image data for recording a still image, obtained at the first exposure time,
Applying a first gain to the first combined image data to generate first still image data having a first brightness;
Before generating the first combined image data, second combined image data is generated by sequentially adding and combining the second image data, wherein the second image data is image data for displaying a live view image. Which is obtained at the second exposure time,
Before generating the first composite image data, applying a second gain to the second composite image data to generate first live view image data having the first brightness, wherein the first live view image data having the first brightness is generated. The second gain is applied every time the second composite image data is generated,
Before generating the first combined image data, the first live view image is updated and displayed at a frame rate for displaying the live view image based on the first live view image data. Shooting method. An imaging unit for imaging a subject, wherein the imaging unit acquires first image data for recording a still image at a first exposure time and acquires second image data for live view image display at a second exposure time. Including shooting equipment,
Generating first combined image data by adding and combining a plurality of first image data repeatedly acquired by the imaging unit until the first total exposure time reaches a third exposure time;
Applying a first gain to the first combined image data to generate first still image data having a first brightness;
Before generating the first combined image data, second combined image data is generated by sequentially adding and combining the second image data acquired by the imaging unit,
Applying a second gain to the second combined image data before generating the first combined image data to generate first live view image data having the first brightness; Is applied every time the second composite image data is generated,
A process of updating and displaying a first live view image at a frame rate for displaying the live view image in the imaging unit based on the first live view image data before generating the first composite image data A program characterized by causing the program to execute.