JP2003324648A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a camera which is capable of easily setting the optimum exposure conditions in hybrid exposure imaging of both silver salt photographing and digital imaging is sought. <P>SOLUTION: The camera consists of a silver salt photographing means 1, digital imaging means 6, photometric circuit 13 for performing photometry on an object by using a photometric element, stroboscopic circuit 12 for supplementarily illuminating the object, exposure-calculating means for calculating and setting exposure conditions of the means 1, 6 on the basis of the photometry of the object obtained by the means 13, and γ table storage means for storing γdata for applying γ-conversion processing to the image data which are imaged and generated by the means 6. In this camera, predetermined γ data are selected by driving of the circuit 12. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to silver having a silver salt photographing means for photographing a subject image on a silver salt film and a digital photographing means for photographing a subject image digitally using an imager composed of a photoelectric conversion element. Regarding exposure control of a camera for combined use of salt and digital photography (hereinafter referred to as a hybrid camera), an exposure control method for performing substantially simultaneous photography with a silver salt film and an imager, and a sequential exposure as represented by a CMOS imager, The present invention relates to exposure control of a hybrid camera using a sequential read drive type imager.

[0002]

2. Description of the Related Art A hybrid camera is provided with a shutter for exposing a subject light on a silver salt film and a shutter for exposing a subject light on an imager. , Charge Coupled Device = CCD) are used.

In such a hybrid camera, when the silver salt film and the imager are imaged at substantially the same time,
In particular, it is necessary to devise an exposure control method for flash photography. That is, how to control the photographing means by the silver salt film and the imager, which have different sensitivities, with a predetermined amount of light and the optimum exposure amount based on one strobe emission.

The following two methods are known as exposure control methods for this hybrid camera.

The first method is an exposure control method mainly using a silver salt film. The exposure control of the silver salt film is equivalent to the publicly known exposure control performed by the silver salt camera,
The brightness and distance of the subject, the aperture value Fno of the silver halide photography optical system,
Also, the shutter speed, shutter aperture value, and strobe light amount are determined by a predetermined program based on the sensitivity of the silver salt film and the like.

On the other hand, when the CCD is used as the imager, the exposure control is such that the opening of the shutter for the CCD is started in accordance with the start of the exposure of the silver salt film. Since the shutter aperture for film is controlled to emit light when the aperture aperture value becomes appropriate, the shutter aperture aperture value for CCD is not appropriate for the strobe light amount in most cases at the time of strobe emission. .

Therefore, considering the amount of strobe light, the aperture value of the shutter for the CCD, and the sensitivity of the CCD,
A method for correcting the apparent proper exposure by processing such as adjusting the gain of the CCD output amplifier is disclosed in Japanese Patent Laid-Open No. 2000-
It is disclosed in Japanese Patent No. 180951.

The second method is to control the exposure timing of the silver salt film and the imager. The exposure control of the silver salt film is the same as the known exposure control described above, but the opening start timing of the shutter for the silver salt film and the opening start timing of the shutter of the imager CCD are not the same but different. .

That is, for the CCD shutter, there is a method of setting the aperture start timing so that the aperture diaphragm value becomes appropriate at the time of strobe light emission.
No. 22 publication.

[0010]

The exposure control method for the hybrid camera disclosed in each of the above publications has two problems.

The first problem is that the photographing optical system for the imager cannot be downsized. In the conventional exposure control method, diaphragm control is basically used, and if the aperture value of the diaphragm is extremely small, there occurs a problem that an optical diffraction phenomenon occurs and the resolution of a digital image to be captured deteriorates. Therefore, there is a limit to the aperture control.

Further, in order to avoid the optical diffraction phenomenon, the minimum aperture value of the shutter diaphragm and the installation position of the shutter diaphragm are restricted, and as a result, the taking optical system becomes large.

The second problem is that as an imager, C
When CMOS is used instead of CD, the aperture control is C
It is not suitable for a sequential exposure image sensor such as a MOS. That is, in the diaphragm using the CMOS imager, the diaphragm aperture value must be kept constant during the exposure period of the CMOS imager. If the aperture opening value is not constant, exposure unevenness will occur in the CMOS imagers of sequential exposure, and trying to avoid this exposure unevenness complicates the aperture mechanism, which hinders cost increase and size reduction. become.

The present invention has been made in view of the above problems, and provides a hybrid camera capable of simultaneous exposure exposure for silver salt photography and digital photography, which can be miniaturized without increasing cost. Prevents underexposure (underexposure) of peripheral objects in images shot with the imager when shooting with the silver salt film and the imager at approximately the same time and in synchronization with flash firing The purpose is to provide a camera that can.

[0015]

A camera of the present invention comprises a first photographing means for photographing a subject using a silver salt film and a second photographing means for photographing a subject using an imager. A photometric unit for performing photometry of the subject using a photometric element, an illumination unit for auxiliary illumination of the subject, and a subject brightness measured by the photometric unit for the subject, the first photographing unit, And exposure calculation means for calculating and setting the exposure condition of the second photographing means, and γ table storage means for storing a plurality of γ data tables used for the γ conversion processing of the image data photographed and generated by the second photographing means, A plurality of gamma tables stored in the gamma table storage means according to the operation of the illumination means when the first and second photography means are driven to be photographed at substantially the same time.
The feature is that a predetermined γ data table is selected from the data table.

The operation of the illuminating means of the camera of the present invention is characterized in that the subject is photographed with strobe light for auxiliary illumination, and is photographed with no strobe light emitted. .

Further, the γ data table stored in the γ table storage means of the camera of the present invention is a γ data table selected when the illumination means is driven and stroboscopic light is emitted for photographing. , A γ data table that is selected when shooting without strobe light emission without driving the illumination means, and a γ data table that is selected when strobe light emission shooting is used for shooting without strobe light emission. Compared with the γ data table selected at that time, it is characterized by having a characteristic of correcting the low-luminance region in the direction of making it brighter.

The camera of the present invention can provide a hybrid camera capable of simultaneous miniaturization of silver salt photography and digital photography without changing the shutter function for silver salt photography as in the prior art, and silver salt photography. Compensation for underexposure (insufficient) due to insufficient strobe light in the image taken by the imager when shooting with the film and the imager at approximately the same time and in synchronization with strobe emission makes it possible to shoot with proper exposure It was

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a camera according to the present invention, FIG. 2 is an explanatory diagram illustrating the configuration of a neutral density filter unit used in a digital photographing means of the camera according to the present invention, and FIG. 3 is a camera according to the present invention. 4 is a flowchart illustrating the basic exposure control operation of the camera, FIG. 4 is a flowchart illustrating the operation of the digital exposure control 1 of the camera according to the present invention, and FIG. 5 is a flowchart illustrating the operation of the digital exposure control 2 of the camera according to the present invention. 6 is an explanatory diagram for explaining gamma correction of the imager of the camera according to the present invention, FIG. 7 is a flowchart for explaining the operation of the digital exposure control 3 of the camera according to the present invention, and FIG. 8 is a digital exposure for the camera according to the present invention. 7 is a flowchart illustrating an operation of control 4.

First, the overall structure of the camera according to the present invention will be described with reference to FIG. The camera according to the present invention has a first photographing means 1 which is a silver salt photographing means and a second photographing means 6 which is a digital photographing means.

The first photographing means 1 is composed of a first optical means 2 and a silver salt film 5. The first optical means 2 condenses the subject light, and the subject light is collected. A lens group (not shown) for projecting and exposing the silver salt film 5, a focus lens 3 for adjusting an image forming focus of the subject light on the exposure surface of the silver salt film 5, and projecting the subject light on the silver salt film 5. The shutter aperture 4 controls the subject light amount and the exposure time.

The second photographing means 6 is composed of a second optical means 7, a neutral density filter means 8 and a light receiving means 9. The second optical means is composed of a lens group that collects subject light and projects and forms the subject light on the exposure surface of the light receiving means 9.

The dimming filter means 8 has a plurality of filters for dimming the subject light projected from the second optical means 7 to the light receiving means 9, and as shown in FIG. A frame 8a formed of a disc-shaped member that does not pass through, for example, is provided with four opening portions in the equiangular direction from the center of the frame 8a,
Optical filters with different dimming amounts that attenuate the intensity of transmitted light are arranged in the four openings.
That is, the transparent optical filter 8b that does not reduce the transmitted light intensity at all, the ND1 optical filter 8c that reduces the light intensity to 1/2, the ND2 optical filter 8d that reduces the light intensity to 1/4, and the light ND3 that reduces the intensity to 1/8
It is composed of an optical filter 8e. However, if the optical filters 8b to 8e have the same thickness and the same material (refractive index), and if the thickness and the material (refractive index) are different, the respective optical filters 8b to 8e are the optical paths of the second image pickup means 6. Set the relationship so that the influence on the length is equal.

The neutral density filter means 8 is rotated by the second drive means 11 about the central axis of the frame 8a. The second drive means 11 includes a motor 11a and a pinion 11b provided on a rotation shaft of the motor 11a.
The pinion 11b meshes with the outer periphery of the frame 8a of the neutral density filter means 8. The motor 11a is driven and controlled by the CPU 24 described later.

The light receiving means 9 comprises a CMOS imager for photoelectrically converting the object image projected and imaged from the second optical means 7 through the neutral density filter means 8, and is supplied from an image signal processing means 17 described later. Under the drive control, the photoelectrically converted image signal is output.

The driving of the entire camera of the present invention is controlled by a microprocessor (hereinafter referred to as CPU) 24.

Focus variable magnification drive of the lens group of the first optical means 2, drive of the focus lens 3 and shutter diaphragm 4,
The winding / rewinding drive of the silver salt film 5 is performed by the first drive means 16 based on a drive control instruction from the CPU 24.

The first drive means 16 is also adapted to drive the finder optical means 15, which will be described later, in conjunction with the first optical means 1 for focus variable magnification drive control.

Further, when the strobe light emitting portion (not shown) has a movable structure, the first driving means 16 can drive and control the strobe light emitting portion to a light emitting position. The strobe light emitting unit has at least a strobe light emitting lamp and a reflector.

In the film loading chamber (not shown) in which the silver salt film 5 is loaded, the type D of the film described on the outer surface of the silver salt film 5, the ISO sensitivity, etc. are displayed.
DX detection means 10 for detecting X information is provided.
The DX detection means 10 detects the DX information of the silver salt film 5 under the drive control of the CPU 24.

The strobe circuit 12 includes a charging circuit for the power source for lighting the strobe light emitting lamp of the strobe light emitting portion (not shown), a lighting control circuit for the strobe light emitting lamp, and the like. The flash emission control for illuminating the subject is performed based on the drive control of.

The photometric circuit 13 is means for detecting the brightness of the subject under the drive control from the CPU 24.
The photocurrent generated in the photodiode is analog-processed according to the brightness of the photodiode and the subject to obtain the photometric value.The photometric method is to measure the light of only one part of the subject or to measure multiple parts. Things, and moreover,
There are various methods such as a method in which a plurality of locations are measured and the average brightness is detected, a method in which the center is emphasized, and the like, but the present embodiment is not particularly concerned with these methods.

The distance measuring circuit 14 is a camera (accurately, the exposed surface of the silver salt film 5) under the control of drive from the CPU 24.
It is means for detecting the distance from the subject to the subject or the defocus amount of the subject image with respect to the exposed surface of the silver salt film 5 and outputting the information necessary for adjusting the focus of the subject image.

As for the distance measuring method of the distance measuring circuit 14, many various methods are known as in the photometering circuit 13, but in the present embodiment, the method is not particularly limited.

The finder optical means 15 is a means for the photographer to confirm the image pickup range of the subject and determine the composition of the image pickup when the photographer takes the image. The finder optical system 15 is also an independent optical system or an optical system that shares a part of the photographing optical system (generally, a TTL optical finder).
However, in the present embodiment, the method is not particularly limited.

The image signal processing means 17 drives and controls the light receiving means 9 on the basis of drive control from the CPU 24, acquires an image signal generated by photoelectric conversion, and processes this image signal. Further, when the image signal is recorded, the image signal is compressed, or conversely, the stored image signal is read out and expanded. The JPEG method or the like is used for this image compression and expansion processing.

Further, the image signal processing means 17 also performs signal conversion into an image signal which can be image-displayed on the first display means 18 described later. In addition to the above, the subject brightness information is extracted from the image signal, the contrast evaluation value of the image signal is calculated, white balance processing, defective pixel correction,
Various image signal processes such as γ correction, color tone correction, various filter processes, edge enhancement, saturation correction, hue adjustment, and Knee process are executed. The detailed description of each image signal process described above is omitted because it is not directly related to the present invention.

The first display means 18 uses a general liquid crystal display element (LCD), an image is picked up by the second image pickup means 6, and the image signal processing means 1 is controlled by the drive control of the CPU 24.
A captured image is displayed by an image signal from the display device 7, a real-time moving image (through image) is displayed, and a menu screen (GUI) is displayed according to camera operation.

The first storage means 19 is a volatile memory for temporarily storing various data subjected to the image signal processing by the image signal processing means 17, and is an SDRAM.

The second storage means 20 is a non-volatile memory for recording and storing the image data obtained by compressing the image signal generated by the image signal processing means 17 under the control of the CPU 24, and is a flash memory. Is used.
As the second storage unit 20, smart media (registered trademark), compact flash (registered trademark), memory stick (registered trademark), and the like, which are storage media that can be detached from the camera, are known. However, in the present invention, it is not essential that the storage unit 20 can be attached to and detached from the camera.

The input means 21 includes various switches such as a release switch, a zoom switch, a mode change switch, and a power switch. The CPU 24 detects information about switches operated by a photographer who is a user, and switches the switches. Processing is executed according to the information.

The second display means 22 displays information such as the date and time and the number of frames photographed on the silver salt film 5 under the control of the CPU 24, and serves as an auxiliary role of the first display means 18. have. In addition, the first display means 18
The second display means 22 consumes less power than the second display means 22, and is always displayed when the camera is powered on.

The clock / imprinting means 23 has a function of setting the date and time, measures the time, and at the same time, the silver salt film 5
It has a function of imprinting date data and so on.

A battery and a power supply circuit for driving each functional means of the camera are not shown, and a program for controlling various functions of the camera by the CPU 24 is a CPU.
It is stored in the internal ROM, or CPU2
It is obvious that the data is stored in a program memory (generally a flash memory) provided outside the memory 4. Further, it is clear that the RAM (work memory, cache memory, etc.) used by the CPU 24 during calculation may be a CPU built-in type or an external memory (generally SRAM).

Further, the first and second storage means 19, 20
May exist in the illustrated number or more, and a plurality of types of storage media may be detachable from the camera.

The operation of the CPU 24 for exposure control at the time of photographing an object of the camera having such a configuration will be described with reference to FIG.

First, the basic operation of the exposure control of the camera will be described with reference to FIG. CPU 24 in step S1
Detects the strobe mode input from the input means 21. The flash modes include an automatic flash mode in which the flash fires when the subject brightness falls below a certain value, a forced flash mode in which the flash fires regardless of the subject brightness value, and a flash inhibit mode in which the flash firing is prohibited regardless of the subject brightness value. Etc. are common. Obviously, a strobe mode other than this light emission mode may be included.

When the strobe mode is detected in step S1, the CPU 24 drives and controls the photometric circuit 13 to measure the brightness of the object and drives the distance measuring circuit 14 to reach the object in step S2. The distance is measured and the DX detection means 10 is driven and controlled to detect the ISO sensitivity from the DX information of the silver salt film 5.

Next, in step S3, the CPU 24 makes the first
The silver salt exposure calculation of the silver salt photographing means which is the photographing means 1 is performed. The silver salt exposure calculation in step S3 is performed by calculating the aperture value (Fno) of the shutter aperture 4 and the shutter speed according to the subject brightness value measured and detected in step S2, the subject distance, the film sensitivity ISO, and the presence / absence of stroboscopic light emission. The exposure condition is calculated by a method called program AE of a known calculation method.

When strobe light is emitted, based on the aperture value (Fno) of the shutter aperture 4 and the subject distance,
The amount of strobe light emission is calculated by a method called flashmatic control.

At the aperture value (Fno) calculated by the silver salt exposure calculation in step S3 and the shutter speed, the drive control setting of the shutter diaphragm 4 of the silver salt photographing means which is the first photographing means 1 is performed and the calculation is performed. It is set so that the strobe circuit 12 is driven by the strobe emission light amount value, but detailed description thereof will be omitted.

Next, in step S4, the CPU 24 determines whether the subject brightness value measured in step S2 is brighter or darker than the first threshold value. The first threshold value is set to a value substantially equal to a value for determining the presence / absence of strobe light emission when the strobe mode is set to the automatic light emission mode.

If the subject brightness in step S4 is higher than the first threshold value, that is, if the subject brightness is high enough that strobe light does not have to be emitted, the CPU 24 proceeds to the digital exposure control 1 in step S5. If the brightness value is a medium / low object brightness value equal to or lower than the first threshold value, the process branches to step S6.

That is, after step S4, the process shifts to a process for controlling the exposure of the digital photographing means which is the second photographing means 6 in accordance with the subject brightness.

Although the details of the digital exposure control 1 in step S5 will be described later, a process for controlling the light receiving means 9 of the second photographing means 6 so as to obtain the optimum exposure with respect to the brightness of the subject regardless of whether or not the strobe is emitted. Is.

If it is determined in step S4 that the subject brightness is medium or low brightness equal to or lower than the first threshold value, it is determined in step S6 whether or not the strobe light is emitted. The presence / absence of the flash emission is determined by branching to the digital exposure control 2 in step S7 if the flash mode detected in step S1 is the automatic flash mode or the forced flash mode, and if it is in the flash inhibition mode, step 8 It branches to the subject brightness determination.

Although the details of the digital exposure control 2 in step S7 will be described later, the light receiving means 9 of the second photographing means 6 is controlled so as to have an appropriate exposure with respect to the amount of stroboscopic light emission, regardless of the brightness of the subject. It is a process to do.

In the subject brightness determination in step S8, the subject brightness measured in step S2 is again compared with the second threshold. This second threshold is the same as in step S
A value equal to or smaller than the first threshold value of 4 is set to a value that divides a low-luminance object in which the strobe is in the light emission prohibition mode and originally requires strobe light emission into medium luminance and low luminance.

If it is determined that the brightness is medium in step S8, the process branches to the digital exposure control 3 in step S9.
If it is determined that the brightness is low, the process branches to the digital exposure control 4 in step S10.

The second darkness value in step S8 is
It is a predetermined subject brightness value and is set based on the characteristics of the second optical means 7, the neutral density filter means 8, the light receiving means 9, and the image signal processing means 17 of the second photographing means 6. .

Although the details of the digital exposure control 3 in step S9 will be described later, the internal gain (signal amplification factor) is adjusted so that the light receiving means 9 of the second photographing means 6 is properly exposed to the brightness of the subject. It is a process to do.

Digital exposure control 4 in step S10
Will be described later in detail, it is a process of adjusting the internal gain and the photographing speed so that the light receiving means 9 of the second photographing means 6 is appropriately exposed to the brightness of the subject.

The image pickup speed is the frame rate (f
ps: frame / second), movie is 30
It is common to shoot 30 frames per second, which is fps. In addition, for example, when it is set to 15 fps, the image pickup time per frame is increased, and it is possible to cope with low brightness capable of long-time exposure.

In this way, after the exposure control of any one of the digital exposure controls 1 to 4 of the second photographing means 6 is performed, the first photographing means 1 and the second photographing means 6 are substantially removed. Although exposure shooting is performed at the same time, description of those exposure shooting operations will be omitted.

Next, the processing of the digital exposure control 1 in step S5 will be described with reference to FIG. As described above, the digital exposure control 1 controls the light receiving means 9 of the second photographing means 6 so as to have an appropriate exposure with respect to the brightness of the subject regardless of whether or not the strobe light is emitted.

In step S11, the CPU 24 acquires the subject brightness (Bv) information measured in step S2. The subject brightness (Bv) information is an apex calculation value indicating the relationship between the aperture value and the shutter speed for the same subject brightness. That is, it is a value calculated and set so that the relationship between the aperture value and the shutter speed and the relationship between the brightness value indicating the brightness of the subject and the silver salt film sensitivity ISO are equal.

That is, the object brightness (Bv) information when it is determined in step S4 that the object brightness is equal to or higher than the first threshold value is 5 or more. The exposure control condition of the second photographing means 6 at the time of photographing a subject having a subject brightness (Bv) of 5 or more is set using Table 1.

[0068]

[Table 1] This Table 1 shows the selection setting values of the dark filter means 8 of the second photographing means 6, the gain of the light receiving means 9, the frame rate, the electronic shutter speed, etc. for the subject brightness (Bv) information. These values are tabulated, and these values are experimentally obtained by the performance and function of the second optical unit 7, the neutral density filter of the neutral density filter unit 8, the light receiving unit 9, and the image signal processing unit 17. It is a thing. In particular, the driving conditions of the neutral density filter means 8 and the light receiving means 9 are set so that the CCD or CMOS imager used for the light receiving means 9 can drive and control within a specific luminance information range for efficient photoelectric conversion.

In other words, since the efficient photoelectric conversion area of the light receiving means 9 is relatively narrow, the photoelectric conversion is saturated when a high quantity of object light above a certain value is input, or a small quantity of light below a certain value. When the subject light is input, sufficient photoelectric conversion is not performed and an unreadable image signal is generated. Therefore, the light receiving means 9 sets the exposure condition for generating the optimum image signal.

Based on the subject brightness (Bv) information acquired in step S11, the CPU 24 executes step S12.
Then, the position of the neutral density filter means 8 is calculated from Table 1. That is, for example, when the subject brightness (Bv) is 8, the transparent filter 8b of the neutral density filter means 8 is selected.

Next, in step S13, the CPU 24 obtains the gain of the light receiving means 9 from Table 1, and in step S14 the image signal processing means 17 is adjusted so that the gain is obtained.
The gain of the light receiving means 9 is set via. That is, the gain of the light receiving means 9 is set to 1 time.

Next, in step S15, the CPU 24 obtains the frame rate of the light receiving means 9 from Table 1, and in step S16, the CPU 24 of the light receiving means 9 operates so as to drive at the obtained frame rate. Set the frame rate. That is, the frame rate of 30 fps is selected.

Next, in step S17, the CPU 24 obtains the speed of the electronic shutter of the light receiving means 9 from Table 1, and in step S18 causes the image signal processing means 17 to drive the light receiving means 9 at the obtained electronic shutter speed. The electronic shutter of the light receiving means 6 is set via the. That is, the subject brightness 8
In the case of, the electronic shutter 14H is set.

That is, in steps S12 to S18, based on the subject brightness (Bv) information, the selection of the neutral density filter of the neutral density filter means 8 of the second photographing means 6 and the light receiving means 9 from the data table of Table 1. The exposure conditions including the gain, the frame rate, and the electronic shutter are set.
Further, the gain of the light receiving means 9 of the second photographing means 6 is 1
The frame rate is fixedly set to 30 fps.

The setting values of steps S12 to S18 are not limited to the method of selecting from the data table shown in Table 1 according to the subject brightness (Bv) information, but the subject brightness (Bv)
It is also possible to use a method of calculating and setting the neutral density filter means 8 and the electronic shutter speed from the v) value and the gain or frame rate of the light receiving means 9 by an arithmetic expression.

Next, in step S19, the CPU 24 drives the neutral density filter means 8 through the second drive means 11 to drive it to the position selected in step S12.

The neutral density filter means 8 in step S19
When the driving of is finished, in step S20, the CPU 24
By driving the light receiving means 9 via the image signal processing means 17,
The subject brightness value is detected by photometry. Based on the subject brightness value measured in step S20, the CPU 2 determines in step S21.
Reference numeral 4 calculates and calculates the electronic shutter speed of the light receiving means 9, and finely adjusts and corrects the electronic shutter speed set in step S18.

In the photometry of the subject brightness using the light receiving means 9 in the step S20, the image signal processing means 17 extracts the image signal of a predetermined area on the light receiving means 9,
There is a method of calculating from the primary color system (R, G, B) or the complementary color system (C, M, Y) of the extracted image signal, but in general,
R, G, B of the image signal generated by the image signal processing means 17
The signal for each color is calculated by Equation 1.

[0079]

## EQU00001 ## Luminance = 0.299R + 0.5787G + 0.114B In addition to correcting the electronic shutter speed, this fine adjustment correction uses the gain of the light receiving unit 9 and the frame rate, or the fine adjustment filter unit 8 for fine adjustment. You may.

As the photometric area, any of various photometric methods such as the average brightness of the central portion of the subject or the entire subject is used.

In this way, after the exposure setting of the digital exposure control 1 of the second photographing means 6 is performed, the silver salt and the digital photographing are executed, and both the silver salt and the digital photographing are based on the proper exposure. To be photographed.

The order of steps S12 to S19 does not necessarily have to be as described above. For example, the necessary setting data may be read from the data table or the necessary setting data may be obtained by an arithmetic expression first. Then
Obviously, the driving of the neutral density filter 8, the gain of the light receiving means 9, the frame rate, and the driving setting of the electronic shutter may be set based on the setting data.

Next, the operation of the digital exposure control 2 in step S7 will be described with reference to FIG. The digital exposure control 2 is a process for controlling the light receiving means 9 of the second photographing means 6 to have an appropriate exposure with respect to the light emission amount of strobe light regardless of the brightness of the subject, and is synchronized with the strobe light emission. Exposure control when shooting a silver salt film and digital shooting at approximately the same time.

In step S22, the CPU 24 causes the silver salt film 5 used in the silver salt exposure calculation in step S3.
The ISO sensitivity information of is acquired.

Next, in step S23, the CPU 24 obtains the aperture value information of the first optical means 2 of the first photographing means 1 calculated by the silver salt exposure calculation in step S3. The aperture value is an open aperture value of the shutter aperture 4 of the first optical unit 2, and is a value that changes according to the magnification of the first optical unit 2. In the silver salt camera, there is a known technique of aperture priority shooting mode. However, the aperture value in this aperture priority shooting mode is not necessarily the full aperture value but the aperture value set by the user. However, in the case of performing program shooting in a regular shooting mode, it is general to set the aperture value to a maximum in flash synchronized shooting.

Therefore, in this step S23, the CPU 24
Detects the open aperture value of the shutter aperture 4 of the first optical means 2.

The CPU 24 may calculate the open aperture value by calculation, or may calculate it from the data table registered in advance. In this case, various input conditions such as the state of the first optical unit 2 (zoom position, magnification, etc.), specifically, a zoom encoder value and a zoom pulse value can be considered.

Next, the CPU 24 obtains the subject distance information when the silver salt exposure calculation of step S3 is performed in step S24, and the subject brightness (Bv) information when the silver salt exposure calculation of step S3 is performed in step S25. To get.

The object distance information and the object brightness information in steps S24 and S25 may be measured and detected by driving and controlling the distance measuring circuit 14 and the photometric circuit 13.

Further, it is apparent that the processing order of the steps S22 to S25 is not limited to the order described above and can be changed.

Using the silver salt film sensitivity ISO, the aperture value of the shutter aperture of the first optical system, the object distance value, and the object brightness value obtained in the processing of steps S22 to S25, the CPU 24 in step S26 determines the second value. The digital exposure amount ΔEv of the photographing means 6 is calculated.

The digital exposure amount ΔEv is a deviation value from the proper exposure amount of the second image pickup means 6, especially the light receiving means 9. Specifically, as the exposure condition of the light receiving means 9, the transparent filter 8b is selected as the dark filter means 8, and the deviation value from the assumption that the output gain of the light receiving means 9 is 1 and the frame rate is 30 fps is set. It is to be calculated.

The digital exposure amount ΔEv, which is the deviation value, is calculated from the deviation value from the proper exposure value with respect to the strobe light and the deviation value from the proper exposure value with respect to the subject brightness.

The appropriate exposure value for strobe light is obtained using Table 2.

[0095]

[Table 2] This Table 2 shows the sensitivity ISO of the silver salt film 5 for silver salt photography,
The focal length of the first optical means 2 and the aperture open value (Fn
o) and the light receiving means 9 of the second photographing means 6 for digital photographing
Is a silver salt film sensitivity ISO100 equivalent, the focal length of the second optical means 7 is equivalent to 38 mm in terms of silver salt film, and a digital value corresponding to the subject distance when the aperture opening value (Fno) is a fixed value of 2.8. A deviation value (error value) from the optimal exposure amount for photographing is experimentally obtained and used as data.

That is, the sensitivity of the silver salt film is IS01.
00, the focal length of the first optical unit 2 is 80 mm, the aperture opening value (Fno) is 9.15, and the subject distance is 5 m,
The digital exposure amount ΔEv is 0.00Ev according to Table 2. This 0.00Ev digital exposure amount is obtained by the light receiving means 9
On the other hand, it means that the strobe light emits with an appropriate amount of light. On the contrary, the light amount becomes insufficient for the silver salt film 5. This is a limitation due to the ability of the strobe circuit 12,
Specifically, as shown in the notes in Table 2, the maximum amount of strobe light (Gno) is limited to 14. In other words, if the strobe circuit 12 has a high performance and the amount of light emission is sufficient to optimize the silver salt film 5, the light receiving means 9 will be overexposed.

That is, the sensitivity of the silver salt film 5 and the light receiving means 9 to the strobe light, the first and second optical means 2,
The proper exposure condition is calculated from the aperture open value of 7 and the subject distance. However, since the sensitivity of the light receiving means 9 and the aperture open value of the second optical means 7 are fixed, the silver salt film sensitivity ISO
By inputting the aperture open value of the shutter aperture 4 and the subject distance, the digital exposure amount ΔEv for the strobe light can be calculated from Table 2.

Next, the proper exposure value for the subject brightness is
It is determined using Table 3.

[0099]

[Table 3] This Table 3 shows the exposure error Δ from the subject brightness (Bv), the proper electronic shutter value of the light receiving means 9 and the actual electronic shutter value.
Ev is required. The exposure error ΔEv in the case where the transparent filter 8b is selected as the neutral density filter means 8 of the second photographing means 6, the gain of the light receiving means 9 is 1 and the frame rate is fixedly set to 30 fps is experimentally determined. It was obtained and converted into data.

On the other hand, in this embodiment, since the light receiving means 9 uses the CMOS imager of the sequential exposure and sequential reading system, the electronic shutter is restricted. That is, it is necessary to limit the electronic shutter value at the timing when all pixels of the CMOS imager are exposed. Specifically, it is necessary to set the full-frame exposure and make the strobe emit light at the timing of exposure of all pixels. Generally, the exposure timing of all pixels comes during the vertical blanking period.

Therefore, for example, the subject brightness (Bv) is set to 4
Then, the proper electronic shutter is 226H, but the actual electronic shutter is 525H, so the deviation value is +
Over exposure of 1.21 Ev.

The electronic shutter values shown in Table 3 are values peculiar to the imager and are not limited to the values shown in Table 3. Further, the unit H of the electronic shutter is 1 in the horizontal direction.
It means line scan, and the value corresponds to time.

In this way, from Table 2, the error ΔEv of the proper exposure amount with respect to the strobe light amount is set to a, and from Table 3 the error ΔEv of the proper exposure amount to the subject brightness is set to b. Deviation value ΔE from the optimum exposure amount
Calculate v.

[0104]

[Equation 2] _{^{ΔEv = log 2 (2 a +2}} b) means that the value of the above-described example in this formula 2, the error Delta] Ev exposure amount with respect to the strobe light intensity a = 0.00Ev
And the exposure error ΔEv with respect to the subject brightness, b =
When calculated using + 1.21Ev, the deviation value ΔEv =
It becomes 1.73 Ev, and the light receiving means 9 is overexposed by 1.73.

In this way, in step S26, it is determined in step S27 whether the deviation value ΔEv from the optimum exposure amount calculated using Table 2, Table 3 and Equation 2 is positive or negative. If the deviation value ΔEv is negative, it is determined to be underexposure (insufficient), or if it is positive, it is determined to be overexposure.

If the result of determination in step S27 is that the deviation value ΔEv is negative and underexposure (ΔEv <0), the CPU 24 determines in step S28 to correct underexposure (ΔEv <0). Calculate the correction amount. This correction amount is an amount for adjusting the internal gain (output gain) of the light receiving means 9, and since the underexposure occurs, the light receiving means 9
The adjustment amount (correction amount) in the direction of increasing the gain of is calculated, and based on the calculated correction amount, CP is calculated in step S29.
U24 sets the internal gain of the light receiving means 9. When this light-receiving unit 9 correction adjustment gain exceeds the upper limit of the gain value that can be set in the light-receiving unit 9, it is set to the upper limit value of the gain.

Next, in step S30, the CPU 24 determines in step S29 whether the correction adjustment gain is equal to or higher than the upper limit gain of the light receiving means 9. That is, it is determined whether the light receiving means 9 has been rounded to the upper limit.

As a result of the determination in step S30, if the upper limit value of the light receiving means 9 is not rounded, it is within the range in which the exposure can be corrected, and it is determined that the light receiving means 9 is corrected and adjusted to the proper exposure, and the digital exposure is performed. Control 2 is ended.

When it is determined in step S30 that the light receiving means 9 has been rounded to the upper limit value, the light receiving means 9 cannot fully compensate the exposure due to insufficient gain, and C in step S31.
The PU 24 performs a γ table changing process. The change of the γ table is a process for aiming at the same effect as the apparent gain of the light receiving unit 9 in the image signal processing of the image signal processing unit 17.

This γ table is changed from the normal γ curve shown in FIG. 6 to the γ curve when the gain is insufficient.

The γ table shown in FIG.
In the table for performing the t-number conversion and the operation of the Knee characteristic, the γ curve when the gain is insufficient has a characteristic that a signal in a bright portion is amplified and a signal including much noise in a dark portion is not amplified. By changing the γ table in this way, it is possible to correct the exposure of at least the main subject portion as appropriately as possible.

Next, as a result of the determination in step S27,
When it is determined that the deviation value ΔEv is negative and is not underexposed (ΔEv <0), the CPU 24 determines in step S32 whether the deviation value ΔEv is positive and overexposed (ΔEv> 0).

If it is determined in step S32 that the deviation value ΔEv is not overexposure (ΔEv> 0), the deviation value ΔEv = 0 in combination with the judgment in step S27.
That is, the light receiving unit 9 can determine that the proper exposure has already been made, and the processing of the digital exposure control 2 ends.

In this embodiment, the divergence value ΔEv = 0 is used for proper exposure, but it is possible to devise steps S27 and S32 so that the proper exposure has a certain range. If it is determined in step S32 that the deviation value ΔEv> 0 is overexposed, the CPU determines in step S33.
Reference numeral 24 drives the neutral density filter means 8 for correcting overexposure, calculates the neutral density filter position so that the light receiving means 9 provides proper exposure, and based on the detection result of the neutral density filter position, In step S34, the CPU 24 drives the neutral density filter means 8 via the second drive means 11 to the calculated neutral density filter position.

It is not always necessary to drive the neutral density filter means 8 at this timing, and the light receiving means 9 is required.
It suffices if the drive is completed before the start of exposure. In particular, those that require a relatively long time such as mechanical driving may be postponed.

Next, in step S35, the CPU 24 determines whether or not further light reduction is necessary because the light reduction filter position of the light reduction filter means 8 calculated and set in steps S33 to S34 is insufficient. If the dimming is sufficient in step S35, the digital exposure control 2 ends, and if it is insufficient, the process branches to step S36.

In step S36, the CPU 24 calculates the internal gain of the light receiving means 9 in order to further correct the insufficient amount of dimming, and based on the calculated correction gain value, step S36 is performed.
At 37, the gain is corrected and set in the light receiving means 9, and the processing operation of the digital exposure control 2 ends.

As a modification of the digital exposure control 2, the branch of the step S35 is deleted and the step S35 is executed.
The coarse adjustment of the exposure correction by the neutral density filter unit 8 in 33 and S34 may be performed, and the fine adjustment may be performed by the exposure correction by the gain of the light receiving unit 9 in Steps S36 and S37.

Next, the processing operation of the digital exposure control 3 in step S9 will be described. This will be described with reference to FIG. The digital exposure control 3 is a processing operation for adjusting the internal gain (signal amplification rate) of the light receiving means 9 of the second photographing means 6 so that the light exposure means 9 has an appropriate exposure with respect to the brightness of the subject without strobe light emission.

In step S38, the CPU 24 acquires the subject brightness (Bv) information when the silver salt exposure calculation in step S3 is performed. The subject brightness (Bv) information is
This is the apex operation value described in step S11.

That is, the subject brightness (Bv) information when it is determined in step S8 that the subject brightness is equal to or higher than the second threshold value is in the range of 0 to 4. Using Table 4, the exposure control condition of the second photographing means 6 at the time of photographing the subject brightness equal to or higher than the second threshold value is set.

[0122]

[Table 4] This Table 4 shows the selection setting values of the dark filter means 8 of the second photographing means 6, the gain of the light receiving means 9, the frame rate, the electronic shutter speed, etc. for the subject brightness (Bv) information. These values are tabulated, and these values are experimentally obtained by the performance and function of the second optical unit 7, the neutral density filter of the neutral density filter unit 8, the light receiving unit 9, and the image signal processing unit 17. It is a thing. In particular, the driving conditions of the neutral density filter means 8 and the light receiving means 9 are set so that the CCD or CMOS imager used for the light receiving means 9 can drive and control within a specific luminance information range for efficient photoelectric conversion.

Based on the subject brightness (Bv) information acquired in step S38, the CPU 24 executes step S39.
Then, the position of the neutral density filter means 8 is calculated from Table 4. That is, the transparent filter 8b of the neutral density filter means 8 is selected.

Next, in step S40, the CPU 24 obtains the gain of the light receiving means 9 from Table 4, and in step S41 the image signal processing means 17 is adjusted so that the gain is obtained.
The gain of the light receiving means 9 is set via.

Next, in step S42, the CPU 24 obtains the frame rate of the light receiving means 9 from Table 4, and in step S43, the CPU 24 of the light receiving means 9 operates so as to drive at the obtained frame rate. Set the frame rate.

Next, in step S44, the CPU 24 obtains the speed of the electronic shutter of the light receiving means 9 from Table 4, and in step S45 the image signal processing means 17 is operated so that the light receiving means 9 is driven at the obtained electronic shutter speed. The electronic shutter of the light receiving means 6 is set via the.

That is, in steps S39 to S45, based on the subject brightness (Bv) information, the selection of the neutral density filter of the neutral density filter means 8 of the second photographing means 6 and the light receiving means 9 from the data table of Table 4. The exposure conditions including the gain, the frame rate, and the electronic shutter are set.

The setting values of steps S39 to S45 are not limited to the method of selecting from the data table shown in Table 4 according to the subject brightness (Bv) information, and
It is also possible to use a method of calculating and setting the neutral density filter means 8 and the electronic shutter speed from the v) value and the gain or frame rate of the light receiving means 9 by an arithmetic expression.

Next, in step S46, the CPU 24 drives the neutral density filter means 8 through the second drive means 11 to drive it to the position selected in step S39.

The neutral density filter means 8 in step S46
When the drive of is finished, in step S47, the CPU 24
The subject brightness value is photometrically detected from the image signal captured by the light receiving unit 9 and generated by the image signal processing unit 17. Based on the subject brightness value measured in step S47, the CPU 24 calculates and calculates the electronic shutter speed of the light receiving means 9 in step S48, and finely adjusts the electronic shutter speed set in step S45.

The fine adjustment correction may be performed by using the gain or frame rate of the light receiving means 9 or the neutral density filter means 8 instead of correcting the electronic shutter speed.

In the photometry of the object brightness using the light receiving means 9 in the step S47, the image signal processing means 17 extracts the image signal of the predetermined area on the light receiving means 9,
From the extracted image signal, it is calculated and calculated by Expression 1.

There are various photometric methods such as using the average brightness of the central area of the subject image or the entire area of the image, and any one of them is used.

In this way, after the exposure setting of the digital exposure control 3 of the second photographing means 6 is performed, the silver salt and the digital photographing are executed, and both the silver salt and the digital photographing are based on the proper exposure. To be photographed.

The order of steps S39 to S46 does not necessarily have to be as described above. For example, the necessary setting data is read from the data table or the necessary setting data is obtained by the arithmetic expression first. Then
Obviously, the driving of the neutral density filter 8, the gain of the light receiving means 9, the frame rate, and the driving setting of the electronic shutter may be set based on the setting data.

As described above, in the digital exposure control 3,
After tentatively determining the exposure condition of the light receiving unit 9 from the table data based on the subject brightness information (Bv), the light receiving unit 9 itself performs photometry, and based on the result, the electronic shack value is corrected and the exposure condition is finely adjusted. It is a thing.

Finally, the digital exposure control 4 in step S10 will be described with reference to FIG. This digital exposure control 4 is used for long-time exposure without flash emission, and when the subject has very low brightness, the internal gain of the light-receiving means 9 and the photographing speed are adjusted so that the second photographing means 6 is properly exposed. Is a process for adjusting.

In step S49, the CPU 24 acquires subject brightness (Bv) information when the silver salt exposure calculation is performed in step S3. The subject brightness (Bv) information is
This is the apex operation value described in step S11.

That is, the object brightness (Bv) information when it is determined in step S8 that the object has a low brightness equal to or lower than the second threshold value is in the range of -1 to -5. The exposure control condition of the second photographing means 6 at the time of photographing the subject brightness of the second threshold value is set using Table 5.

[0140]

[Table 5] This Table 5 shows the selection setting values of the dark filter means 8 of the second photographing means 6, the gain of the light receiving means 9, the frame rate, the electronic shutter speed, etc. with respect to the subject brightness (Bv) information. These values are tabulated, and these values are experimentally obtained by the performance and function of the second optical unit 7, the neutral density filter of the neutral density filter unit 8, the light receiving unit 9, and the image signal processing unit 17. It is a thing. In particular, the driving conditions of the neutral density filter means 8 and the light receiving means 9 are set so that the CCD or CMOS imager used for the light receiving means 9 can drive and control within a specific luminance information range for efficient photoelectric conversion.

The CPU 24 executes step S50 based on the subject brightness (Bv) information acquired in step S49.
Then, the position of the neutral density filter means 8 is calculated from Table 5. That is, the transparent filter 8b of the neutral density filter means 8 is selected.

Next, in step S51, the CPU 24 obtains the gain of the light receiving means 9 from Table 5, and in step S52 the image signal processing means 17 is adjusted so as to obtain the gain.
The gain of the light receiving means 9 is set via.

Next, in step S53, the CPU 24 obtains the frame rate of the light receiving means 9 from Table 5, and in step S54, the CPU 24 of the light receiving means 9 operates so as to drive at the obtained frame rate. Set the frame rate.

Next, in step S55, the CPU 24 obtains the speed of the electronic shutter of the light receiving means 9 from Table 5, and the image signal processing means 17 is operated in step S56 so that the light receiving means 9 is driven at the obtained electronic shutter speed. The electronic shutter of the light receiving means 6 is set via the.

That is, in steps S50 to S56, based on the subject brightness (Bv) information, the selection of the neutral density filter of the neutral density filter means 8 of the second photographing means 6 and the light receiving means 9 from the data table of Table 5. The exposure conditions including the gain, the frame rate, and the electronic shutter are set.

The setting values of steps S50 to S56 are not limited to the method of selecting from the data table shown in Table 5 according to the subject brightness (Bv) information, and
It is also possible to use a method of calculating and setting the neutral density filter means 8 and the electronic shutter speed from the v) value and the gain or frame rate of the light receiving means 9 by an arithmetic expression.

Next, in step S57, the CPU 24 drives the neutral density filter means 8 via the drive means 2 to drive it to the position selected in step S50.

The neutral density filter means 8 in step S57
When the drive of is completed, silver salt and digital photography are executed,
Both silver salt and digital photography are taken under the proper exposure.

The order of steps S50 to S57 does not necessarily have to be as described above. For example, the necessary setting data may be read from the data table or the necessary setting data may be obtained by an arithmetic expression first. Then
Obviously, the driving of the neutral density filter 8, the gain of the light receiving means 9, the frame rate, and the driving setting of the electronic shutter may be set based on the setting data.

As described above, the digital exposure control 4 is similar to the operation of the digital exposure control 3 described above, but when the low-luminance subject is exposed for a long time, the digital exposure control 3 uses the light receiving means. 9 performs the fine adjustment and correction of the exposure condition by itself, while the digital exposure control 4 controls the subject brightness (B
v) The exposure condition is uniquely determined based on the information.

As described above, the camera of the present invention is
First, set the exposure conditions so that the silver halide film shooting will be the proper exposure, and then perform four types of digital exposure control according to the subject and camera shooting state and the strobe emission amount, so that almost all subjects will be exposed. Both silver salt photography and digital photography have proper exposure, and simultaneous photography is possible.

[0152]

The camera of the present invention can be downsized without changing the shutter function as in the prior art, and can be used when shooting with a silver salt film and an imager at substantially the same time and in synchronization with stroboscopic light emission. The underexposure (insufficiency) of the imager shooting has an effect of obtaining the proper exposure shooting of the imager shooting by γ correction of the image signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a camera according to the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of a neutral density filter unit used in a digital image capturing unit of a camera according to the present invention.

FIG. 3 is a flowchart illustrating a basic exposure control operation of the camera of the present invention.

FIG. 4 is a flowchart illustrating an operation of digital exposure control 1 of the camera of the present invention.

FIG. 5 is a flowchart for explaining the operation of the digital exposure control 2 of the camera of the present invention.

FIG. 6 is an explanatory diagram illustrating gamma correction of the imager of the camera according to the present invention.

FIG. 7 is a flowchart illustrating an operation of digital exposure control 3 of the camera of the present invention.

FIG. 8 is a flowchart illustrating an operation of digital exposure control 4 of the camera of the present invention.

[Explanation of symbols]

1 ... First photographing means (silver salt photographing means) 2 ... second optical means 3 ... Focus lens 4 ... Shutter diaphragm 5 ... Silver salt film 6 ... Second photographing means (digital photographing means) 7 ... Second optical means 8 ... Neutral filter means 9 ... Light receiving means 10 ... DX detection means 11 ... Driving means 12 ... Strobe circuit 13 ... Photometric circuit 14: Distance measuring circuit 17 ... Image signal processing means 24 ... Control means (CPU)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/238 H04N 5/238 Z F term (reference) 2H002 AB04 EB09 JA09 2H053 AA06 AB03 BA71 2H054 AA01 BB07 2H104 AA18 5C022 AB02 AB13 AB15 AB17 AB22 AB40 AC02 AC03 AC13 AC42 AC55 AC74

Claims (3)

[Claims] 1. A first photographing means for photographing a subject using a silver salt film, a second photographing means for photographing a subject using an imager, and a subject metering using a photometric element. A photometric unit for performing, an illuminating unit for illuminating the subject in an auxiliary manner, and a subject brightness measured by the subject by the photometric unit,
An exposure calculation unit for calculating and setting exposure conditions of the first photographing unit and the second photographing unit, and a plurality of γ data tables used for γ conversion processing of image data photographed and generated by the second photographing unit are stored. And a γ table storage means for storing images in the γ table storage means according to the operation of the illumination means when the first shooting means and the second shooting means are driven for substantially simultaneous shooting. A camera characterized by selecting a predetermined γ data table from a plurality of γ data tables. 2. The operation of the illuminating means is a case where a subject is photographed with strobe light for auxiliary illumination, and a case where the subject is photographed without the strobe light being emitted. The listed camera. 3. The γ data table stored in the γ table storage means includes a γ data table selected when the illumination means is driven and strobe light is emitted to take an image, and the illumination means. It has a γ data table that is selected when shooting without driving and strobe light emission, and the γ data table that is selected when shooting with strobe light emission is selected when shooting without strobe light emission. 2. The camera according to claim 1, further comprising a characteristic for correcting the low-luminance region to be brighter than that of the γ data table.