JP2002277934A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a camera capable of photographing even under such a condition that it is impossible to take a photograph with a conventional electronic flash by making the electronic flash emit light several times so as to compensate for the shortage of light. SOLUTION: The camera which is equipped with an electronic flash 53 and which controls the emitted light quantity of the electronic flash 53 in accordance with the photographing condition so as to obtain the optimum exposure is further provided with a calculation part 3 for calculating the emission light quantity of the electronic flash 53 in accordance with the photographing condition, and a control part 4 for making the electronic flash 53 emit light several time so as to obtain the optimum exposure in the case that the light quantity is insufficient with a single light emission according to the result of the calculation by the calculation part 3. The calculation part 3 calculates the number of light emission for obtaining the optimum exposure, and a display part 6 displays the calculation result. The control part 4 performs multiple exposure until the optimum exposure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a strobe light emitter, which emits light in synchronization with opening and closing operations of a shutter of a camera to illuminate a subject. The present invention relates to a camera that can emit light a plurality of times to compensate for the lack of light.

[0002]

2. Description of the Related Art A strobe light emitter mounted or incorporated in a camera mainly emits illumination light and irradiates the object as auxiliary light when the luminance of the object is low and the exposure is insufficient, so that the exposure is insufficient. Used to supplement. However, if the amount of light from the strobe light emitter is too large, overexposure will occur. Therefore, in the conventional camera, the amount of light emitted from the strobe light emitter is controlled in accordance with shooting conditions to obtain an appropriate amount of road light. Generally, light emission is stopped when the appropriate road light amount is reached.

[0003]

A conventional camera having a strobe light emitter is effective under photographing conditions in which a proper light can be obtained by one light emission. However, depending on the photographing conditions, the amount of light required for proper exposure may not be reached by only one light emission. For example,
If the subject distance is long, the guide number of the strobe light emitter is small, or if it is desired to shoot with a small aperture value, the exposure tends to be insufficient even when the flash is used for synchronous flash shooting.

[0004] The present invention has been made to solve the above-mentioned problems of the prior art.
Even if the amount of light required for proper exposure does not reach the value required for a single light emission, that is, even under conditions where a conventional camera having a strobe light emission cannot capture images, the insufficient amount of light is compensated by causing the strobe light emitter to emit light a plurality of times. It is an object of the present invention to provide a camera capable of shooting.

According to the present invention, in order to compensate for a shortage of light quantity by making a strobe light emitter emit light a plurality of times, shooting conditions such as a case where the number of times of strobe light emission exceeds a specified number or a case where an exposure time exceeds a specified value are used. It is an object of the present invention to provide a camera that issues a warning when it is too bad and prompts the user to stop shooting.

[0006]

According to the first aspect of the present invention,
A camera having a strobe light emitter, and controlling a light emission amount of the strobe light emitter according to photographing conditions to obtain an appropriate amount of road light,
A calculation unit for calculating the light emission amount of the strobe light emitting device in accordance with the photographing condition; and a plurality of the strobe light emitting devices for obtaining an appropriate road light amount when a single light emission amount is insufficient as a result of the calculation by the calculation unit. And a control unit for emitting light once.

According to a second aspect of the present invention, in the first aspect of the present invention, the calculating section has a display section for calculating the number of times of light emission for obtaining an appropriate amount of road light and displaying the calculation result. . According to a third aspect of the present invention, in the first aspect of the invention, the control unit causes the multiple exposure to be performed until an appropriate amount of road light is obtained.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the control unit sets the shutter operation mode to a valve mode, and charges and emits light from the main capacitor of the strobe light emitter until an appropriate amount of road light is reached. It is characterized in that multiple emission photographing is repeatedly performed.

According to a fifth aspect of the present invention, in the first aspect of the present invention, there is provided a warning means for giving a warning when the number of times of flash emission exceeds a prescribed number or when the exposure time exceeds a prescribed value. And According to a sixth aspect of the present invention, in the first aspect of the present invention, there is provided a warning means for giving a warning when the charging time of the main capacitor of the strobe light emitter exceeds a prescribed value.

[0010] According to a seventh aspect of the present invention, in the first aspect of the invention, the control unit, when the appropriate amount of road light is reached while the shutter is open, stops the emission of the strobe light and interrupts the exposure by closing the shutter. And is performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a camera according to the present invention will be described with reference to the drawings. Figure 1
Shows an example of an electrical signal system in one camera. This signal system is roughly divided into an input unit 1, a detection unit 2 for various information, a calculation unit 3, a camera control unit 4, an output unit 5, a display 6, and a restriction information input unit 7 for the number of times of multiple light emission.

The input unit 1 is an input unit 1 for film information.
1. It has an auto focus (AF) unit 12 and a photometric unit 13. Input unit 11 for film information
Is a section for mainly inputting the film sensitivity, and generally detects a code provided in the film cartridge and automatically inputs the code. Of course, the input may be performed by the camera user confirming the film sensitivity and manually setting the film sensitivity.
From the auto-focus unit 12, shooting distance information (subject distance information) measured by the unit is input. From the photometric unit 13, subject brightness information measured by the unit is input.

The various information detecting section 2 is provided with the input section 1
This is a part that detects various types of information from the camera and various types of information from each part of the camera, converts them as appropriate, and inputs them to the arithmetic unit 3. Various types of information can be divided into shooting information and flash information.
The photographing information includes information such as film sensitivity (displayed in, for example, ISO), aperture value, photographing distance, and shutter speed. As the strobe information, there are information such as a guide number indicating a light emission amount of the strobe light emitter, a charging time until a terminal voltage of the main capacitor reaches a predetermined voltage, and the like. All of these pieces of information are information relating to shooting conditions.

The calculating section 3 reads various information input from the detecting section 2, that is, information relating to photographing conditions, and computes the light emission amount of the strobe light emitter according to the photographing conditions. In addition, as a result of the calculation, when the light amount is insufficient with one light emission amount, the number of times of light emission of the strobe light emitter necessary for obtaining the appropriate road light amount is calculated.

The camera control section 4 is a section for controlling the operation of each section of the camera and the strobe light emitter based on the calculation result of the calculation section 3. The camera control unit 4 selects the normal photographing control mode when the number of flashes of the strobe light emitting device is one or less as a result of the calculation by the calculating unit 3, and the strobe light emission when the number of flashes of the strobe light emitting device is one or more. The multi-emission shooting mode by the device is selected, and each unit is controlled in the selected shooting mode.

The output unit 5 is a part whose operation is controlled by the camera control unit 4, and includes a shutter 51, an aperture 5
2. It has a strobe light emitter 53. Camera control unit 4
When shooting using the strobe light emitting device 53, the timing is controlled so that the opening timing of the shutter 51 and the light emitting timing of the strobe light emitting device 53 are synchronized at a predetermined timing, and the shutter speed is suitable for synchronous light emitting shooting. The shutter 51 is controlled so that the speed is increased. Also, control is performed so that the aperture value at that time becomes a predetermined aperture value.

As a result of calculation from the various photographing conditions by the calculation unit 3, if a proper road light cannot be obtained with a single light emission of the strobe light emitting unit 53, the camera control unit 4 sets the multiple emission photographing mode to the appropriate light emission mode. Exposure is performed by causing the strobe light emitter 53 to emit light a plurality of times. At this time, the shutter 51
May open and close each time the strobe light emitting device 53 emits light to perform shooting by so-called multiple exposure, or switch to the bulb mode,
May be opened while light is emitted a plurality of times, and may be closed when the proper exposure is completed and the exposure is completed. It is natural that the film is not wound up during the exposure by the light emission in the bulb mode a plurality of times. Is not performed.

The restriction information input section 7 for the number of times of multiple light emission is
The number of times of light emission when shooting with the strobe light emitting device emitting a plurality of times is input in advance, and if the number of times is exceeded, a warning is issued to urge the user to stop shooting. If the required number of times of light emission exceeds a certain number, the photographing conditions are too bad to obtain a good photographed image, and a warning is issued in such a case. If this warning is given by the camera user to give up shooting, the film can be prevented from being wasted. Alternatively, a shutter release prohibition process may be performed instead of, or in addition to, the warning to prevent an inadvertent long exposure. In the above warning, when the actual number of times of light emission exceeds the number of times of light emission input from the multiple information on the number of times of light emission restriction unit 7, the camera control unit 4 drives the display 6 to display the fact.

The warning at the time of the multiple light emission photographing is performed instead of when the number of times of the multiple light emission is equal to or more than the specified value as described above or when the exposure time exceeds the specified value. Is also good. This is because if the exposure time is too long, a clear image cannot be obtained because the subject moves or the camera shakes.

The warning at the time of the multiple emission photographing may be issued even when the charging time of the main capacitor of the strobe light emitter exceeds a prescribed value. If the charging time of the main capacitor exceeds the specified value, it means that the power battery is depleted.
This is because there is no guarantee that the terminal voltage of the main capacitor reaches a predetermined voltage, or that the number of times of light emission required to obtain an appropriate road light within a prescribed time is not guaranteed.

The display unit 6 displays the number of times of light emission of the strobe light emitting device for obtaining the appropriate road light, calculated by the calculating unit 3. The display unit 6 also displays a warning when the number of times of light emission of the strobe light emitter exceeds the specified value, when the exposure time exceeds the specified value, and when the charging time of the main capacitor of the strobe light device exceeds the specified value, as described above. Is displayed. These displays may be visual or displayed by sound.

Next, an example of a calculation in the calculation unit 3 will be described. The arithmetic unit 3 calculates the number of times of strobe light emission necessary to compensate for the shortage of light amount from the strobe light emission amount L1 obtained from the photographing conditions and a preset or known strobe light emission amount L2 according to the following equation. It is obtained by calculating. Number of times of light emission = 2 ＾ ((LN (L1 / L2)) / (LN (S
QR (2)))) The integer part of the numerical value obtained by the above equation is the number of times of full emission, and the decimal part is the last emission requiring control of the emission light quantity and represents the emission light quantity to be controlled. I have.

For example, if the strobe light emission amount L1 obtained from the photographing conditions, that is, the required guide number is "2"
2 ", the guide number of the strobe light emitter is" 9 ", and the film sensitivity is ISO: 100, Becomes This means that it is necessary to emit six full light emissions and an additional light emission amount of 0.87. LN
0.87 / LN2 = −0.20, and the emission guide number of −0.20 EV is “8.4” for the guide number “9”, that is, the emission 6 of the guide number “9”.
Each time, one light emission of the guide number "8.4" requires a total of seven light emissions. At this time, the display 6 displays “7” as the number of times of light emission. The display on the display 6 at this time is performed by an LED, an LCD, or the like.

The display by the display 6 may be the total photographing time including the charging time of the main capacitor of the strobe light emitter. For example, if the charging time of the main capacitor is 3
If it is set to seconds, it is assumed that the charging required for the first light emission is completed, and (7-1) × 3 = 18 (seconds). Therefore, “18” is displayed as the total shooting time.

The camera control unit 4 shown in FIG. 1 operates in a case where the appropriate amount of road light is reached when the shutter is open, that is, when the appropriate amount of road light is reached at the time of the last light emission in the above-described example. The light emission of the light emitter is stopped and the exposure is stopped by closing the shutter. Proper exposure can be obtained by stopping the emission of the strobe light, and excessive exposure due to unnecessary reflection of ambient light due to interruption of exposure by closing the shutter can be prevented.

When the exposure is performed by the multiple light emission of the strobe light emitter, the shutter may be in the bulb mode as described above, or may be opened and closed in synchronization with each light emission. When so-called multiple exposure is performed in which the shutter is opened and closed in synchronization with each light emission, mechanical vibration and vibration due to the opening and closing operation of the shutter may occur, which may adversely affect the performance of a captured image. There is an advantage that unnecessary exposure due to ambient light can be reduced while the main capacitor is being charged for the next light emission after one light emission. On the other hand, in the bulb mode, unnecessary exposure due to ambient light may be performed while the main capacitor is being charged.On the other hand, since there is no frequent opening / closing operation of the shutter, there is no occurrence of mechanical shake or vibration, and photographing is performed. There is an advantage that there is no possibility of adversely affecting the performance of the image. Whether to use multiple exposure mode or bulb mode
Either one may be determined by the camera designer, or the camera user may be able to select one.

When photographing is performed by multiple light emission of the strobe light emitting device, the strobe light emitting device emits light a plurality of times,
If the time during which the shutter is open is longer than the proper exposure time, the exposure by strobe light emission is interrupted after the proper exposure time has elapsed, thereby preventing overexposure.
For example, if the proper exposure time is 10 seconds, the shutter is opened for 10 seconds in the bulb photography mode, and the strobe light is emitted four times during that time, and if the exposure is interrupted, the multi-exposure photography is completed with seven flashes. Becomes

[0028]

In a camera having a conventional strobe light emitting device, if the main condenser is fully charged and the shooting distance is shorter than a shooting distance at which proper exposure can be obtained when the main capacitor is fully fired, light emission is controlled. Appropriate exposure can be obtained. However, since the shooting is performed by one flash of the strobe light emitting device, the proper exposure cannot be obtained if the shooting distance is longer than a shooting distance at which the proper exposure can be obtained by full flash.
I had to give up shooting. On the other hand, according to the invention of claim 1 of the present application, since multiple light emission by the strobe light emitting device is enabled, it is possible to take a picture with an appropriate exposure even at a photographing distance where photographing was abandoned in the past.

According to the second aspect of the present invention, the number of times of light emission of the strobe light emitting device for obtaining proper exposure is calculated and the result is displayed on the display unit, so that the camera user can use the ordinary strobe light emitting device. It is possible to discriminate between the used shooting and the multiple emission shooting, and to recognize the number of flashes in the multiple emission shooting.

According to the third aspect of the present invention, the multiple exposure is performed by repeating the opening and closing of the shutter and the emission of the strobe light in synchronization with the shutter until the proper exposure is achieved. And unnecessary exposure can be reduced.

According to the fourth aspect of the present invention, since the shutter is operated in a valve mode to perform multiple light emission until proper exposure is performed, there is no frequent opening / closing operation of the shutter. There is no risk of adversely affecting the performance of the captured image.

According to the fifth and sixth aspects of the present invention, it is possible to prevent the multiple emission photographing from taking an excessively long time.

According to the seventh aspect of the present invention, when the appropriate amount of road light is reached, light emission is stopped and exposure is interrupted by closing the shutter, so that overexposure due to natural light can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a camera according to the present invention.

[Explanation of symbols]

 3 arithmetic unit 4 control unit 6 display unit 53 strobe light emitter

Claims (7)

[Claims] 1. A camera having a strobe light emitter and controlling a light emission amount of the strobe light emitter according to photographing conditions to obtain an appropriate amount of road light, and calculating a light emission amount of the strobe light emitter according to the photographing conditions. And a control unit for causing the strobe light emitter to emit light a plurality of times in order to obtain an appropriate amount of road light when the amount of light emitted by one operation results in an insufficient amount of light. 2. The camera according to claim 1, wherein the calculation unit has a display unit for calculating the number of times of light emission for obtaining an appropriate road light amount, and displaying the calculation result. 3. The camera according to claim 1, wherein the control unit performs multiple exposures until the light quantity reaches an appropriate value. 4. The control unit performs a multiple emission photographing by repeatedly charging and emitting a main capacitor of a strobe light emitting device until an appropriate amount of road light is reached, with a shutter operation mode being a valve mode. The camera according to 1. 5. The camera according to claim 1, further comprising warning means for giving a warning when the number of times of strobe light emission exceeds a prescribed number or when the exposure time exceeds a prescribed value. 6. The camera according to claim 1, further comprising warning means for giving a warning when the charging time of the main capacitor of the strobe light emitter exceeds a prescribed value. 7. The control unit according to claim 1, wherein when a proper amount of road light is reached in a state where the shutter is open, emission of the strobe light emitter and interruption of exposure by closing the shutter are performed. camera.