JPH0566457A - Camera - Google Patents

Abstract

PURPOSE:To secure exposure required for photographing even in the case that an object distance is too long for strobe light to reach and to eliminate the blurring of the object which is a moving object. CONSTITUTION:This camera is provided with a synchronizing time setting means CPU 2 which judges whether or not the result of range-finding by a range-finding means 5 is longer than a specified distance at the time of setting photographing with strobe light, and sets a shutter synchronizing time to a 1st time when it is short and sets it to a 2nd time longer than the 1st time when it is long. When the object is the moving body, the synchronizing time setting means is inhibited from setting the shutter synchronizing time to the 2nd time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera capable of stroboscopic photography.

[0002]

2. Description of the Related Art Conventionally, there is known a camera with a built-in strobe that automatically emits a strobe light when it is determined that a subject has low brightness. And this built-in flash camera
The shutter was set to open at a fixed time limit.

Further, when a moving subject (moving body) is photographed, distance measurement is repeatedly performed several times to calculate the amount of movement of the subject from continuous changes in the distance measurement value, and the shutter is opened. There has been proposed a camera having a moving body prediction function that predicts the position of a subject at the time of performing and determines a shooting distance.

[0004]

However, in the former camera with a built-in strobe, since there is a certain limit to the amount of strobe light emission, the strobe light does not reach when the subject is farther than the certain limit distance, There is a problem that a desired exposure amount cannot be obtained.

On the other hand, in the latter built-in camera having a moving body prediction function, subject blurring is likely to occur when the shutter opening time is long when the moving body prediction function is activated.

An object of the present invention is to provide a camera capable of ensuring an exposure amount necessary for photographing even when a subject is far away and strobe light does not reach. Also,
Another object of the present invention is to provide a camera that secures at least an exposure amount necessary for shooting and does not cause a subject blur when the subject is a moving body.

[0007]

In order to solve the above-mentioned problems, a camera according to the present invention is provided with a distance measuring means, and in a camera capable of stroboscopic photography, a setting means for setting stroboscopic photography and a strobe by the setting means. When shooting settings,
A determination means for determining whether or not the distance measurement result by the distance measurement means is farther than a predetermined distance, and a shutter synchronization time is set to the first second when the distance is judged to be closer by the judgment means, and the distance is judged to be far. When the shutter speed is adjusted, the shutter synchronization time is set to a second time which is longer than the first time, and a synchronization time setting means is provided.

Further, the camera according to the present invention is provided with a distance measuring means, and in a camera capable of stroboscopic photography, a setting means for setting stroboscopic photography, a strobe synchronization time of a first second and a first time thereof. When the second time is longer than the second time, the synchronization time setting means, the moving body detecting means for detecting whether or not the subject is moving, and the stroboscopic photography setting by the setting means, depending on the output of the moving body detecting means. The synchronizing time setting means may include a prohibiting means for prohibiting setting the shutter synchronizing time to the second second.

In this case, there is provided a mode setting means for setting a moving body prediction mode for continuously measuring the distance and predicting the position of the subject at the time of opening the shutter to determine the photographing distance. When the setting is made, the moving body detecting means may perform a detecting operation.

[0010]

According to the present invention, it is determined whether or not the distance measurement result is farther than a predetermined distance when the flash photography is set, and when it is determined that the distance measurement result is closer, the shutter synchronization time is set to the first second and the distance is far. If it is determined that the shutter synchronization time is set to the second time, which is longer than the first time, even if the exposure amount is insufficient due to insufficient arrival of the strobe light, the shutter synchronization time is set. The exposure amount can be supplemented by prolonging the opening time.

Further, when the flash synchronization time can be set to the first time and the second time which is longer than the first time, it is detected whether or not the subject is moving at the time of setting the flash photography. According to the result, it is prohibited to set the shutter synchronization time to the second time. Therefore, in the case of a moving object, it is possible to prevent the subject blurring due to the long shutter opening time. .. At this time, since the moving object is detected when the moving object prediction mode is set, it is possible to prevent the function of improving the distance measurement accuracy in the moving object prediction mode from being destroyed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a camera according to the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of a camera according to the present invention, FIG. 1 is a flow chart showing the flow of the entire processing, FIG. 2 is a flow chart showing the first half of the photographing processing of the camera, and FIG. 4 is a flowchart showing the latter half of the photographing process, FIG.
FIG. 5 is a flowchart showing a moving object prediction mode setting process, and FIG. 5 is a block diagram showing a main part of the circuit. It should be noted that the processes shown in the flowcharts of FIGS. 1 to 4 show only the part related to this embodiment among the programs contained in the CPU 2 of FIG.

First, the circuit configuration of the camera according to this embodiment will be described with reference to FIG. The CPU 2 includes a main switch 7 for starting a camera operation, a half-push switch 8 that is turned on by half-pressing the release button, a release switch 9 that is turned on by fully-pressing the release button, and a moving object prediction mode. The moving object prediction mode setting switch 10 for selecting is connected.

An LCD (liquid crystal display) 3, a photometry circuit 4, a distance measurement circuit 5, a strobe (hereinafter abbreviated as "SB") circuit 6 and the like are connected to the CPU 2.
The LCD 3 is arranged on the camera body and has a CPU.
2 has a function of displaying necessary information to the outside, such as whether or not the moving body prediction mode is selected according to the signal output by 2.

The photometry circuit 4 measures the luminance of the subject at a necessary timing according to an instruction from the CPU 2, and the result is C
It has a function of transferring to PU2. The distance measuring circuit 5 is a CPU
It has a function of measuring the distance to the subject at a necessary timing according to the instruction of 2, and transferring the result to the CPU 2.

The SB circuit 6 has a function of emitting SB in synchronization with a release based on a trigger signal output from the CPU 2 when it is determined that the photometric result is low luminance. CPU
2, the photometry circuit 4, the distance measurement circuit 5, and the SB circuit 6 are connected to the battery 1 serving as a power source for them. Note that C
The PU 2 is composed of a one-chip microcomputer, and has a function of controlling the entire sequence of the camera and a function of driving the LCD 3 in addition to the above.

Next, the flow of processing of the entire camera according to this embodiment will be described with reference to FIG. The autofocus mode of this camera has two modes: a moving object prediction mode and a normal autofocus mode (hereinafter, autofocus may be referred to as “AF”). Also, the battery has already been put in.

When the main switch 7 is turned on, the process starts from S100. The main switch 7 is a state switch having an on position and an off position, and once the photographer sets the on position, the main switch 7 holds the on position until it is returned to the off position again. First, in S101, the normal autofocus mode is set, and in S102, it is displayed on the LCD 3 that the normal autofocus mode is selected.

Subsequently, in the loop of S103, S104 and S105, the half-push switch 8 is operated, the moving object prediction mode setting switch 10 is turned on, or
Wait for the main switch 7 to be turned off. If it is confirmed in S103 that the half-push switch 8 is turned on, the process proceeds to S107 to call the photographing process. When it is confirmed that the moving object prediction mode setting switch 10 is turned on in S104, the process proceeds to S108 to call the moving object prediction mode setting process.

The photographing process and the moving object prediction mode setting process will be described in detail later, but when these processes are completed, S10 is executed.
Return to the loop of S3, S104, and S105, and continue to check each switch again. When it is confirmed in S105 that the main switch 7 is off, the process proceeds to S106 and ends the process. After that, it waits for the main switch 7 to be turned on again, and when the main switch 7 is turned on, the process is restarted from S100.

Next, the flow of the photographing process shown in S107 in FIG. 1 will be described with reference to FIGS. 2 and 3. When it is confirmed in S103 of FIG. 1 that the halfway press switch 8 is turned on, the process proceeds to S107, and the photographing process of FIG. 2 is called. S
When the photographing process starts from 200, first in S201, the CPU 2 sends a ranging start signal to the ranging circuit 5, and the ranging circuit 5 starts the ranging process. Although the known distance processing is applied to the distance measuring processing, details thereof will be omitted, but when the distance measuring is completed, the distance measuring circuit 5 outputs the distance measuring result to the CPU 2. continue,
In S202, the CPU 2 sends a photometry start signal to the photometry circuit 4 to execute photometry processing. Although details of the photometric processing are omitted as in the distance measuring processing, the brightness of the subject is calculated from the amount of light input to the light receiving element in the photometric circuit 4.

Next, in step S203, the opening time of the shutter is calculated from the brightness of the subject obtained by the photometric circuit, and the process proceeds to step S204. In S204, it is determined whether the subject has low brightness.
Based on the brightness of the subject, when the opening time calculated in S203 is longer than a predetermined value (here, 1/70 second is selected as the second time that does not cause subject blurring), it is determined to be low brightness. If the brightness is not low, the process proceeds from S204 to point A. On the other hand, when the brightness is low, S204 to S20
The process proceeds to 5 to set the SB emission mode.

After the SB light emission mode is set, it is determined in S206 whether or not the distance measurement result obtained in S201 is longer than a predetermined distance. The predetermined distance is determined based on the SB guide number and the ISO value of the film. If it is determined that the distance measurement result is not longer than the predetermined distance, the process proceeds to S2.
From 06 to S208, set the shutter opening time to 1/70
Set to seconds. 1/70 second is the first time limit for opening the shutter. On the other hand, if it is determined that the distance measurement result is a distance longer than the predetermined distance, the process proceeds from S206 to S206.
Proceed to 207.

In S207, it is determined whether the autofocus mode is set to the moving object prediction mode or the normal autofocus mode. In the moving body prediction mode, that is, when the moving body prediction function is operating, the process proceeds from S207 to S208, and the shutter opening time is set to 1/70 seconds. Therefore, when the moving body prediction function is operating, the occurrence of subject blurring is prevented.

On the other hand, when the moving object prediction mode is not set, that is, when the moving object prediction function is not operating, the steps from S207 to S207 are performed.
The process proceeds to 209. The opening time is 1 in S209.
It is judged whether it is longer than / 4 seconds, and 1/4 second (this 1/4
The second becomes the second time limit of the shutter opening time. ) Is longer, the process proceeds to S210, and the shutter opening time is set to 1/4 second. If it is not longer than 1/4 second, the value calculated in S203 is used as it is as the opening time. Through this series of processing, the shutter opening time according to the brightness of the subject is set within the range of 1/70 second or more and 1/4 second or less. Therefore, the insufficient exposure amount can be compensated by increasing the shutter opening time.

Thereafter, the process proceeds to S211. S211
Then, it is confirmed whether or not the SB has been charged. If charging is completed, the process proceeds to point A. If the charging is not completed, the process proceeds to S212 and waits for the half-press switch 8 to be turned off. No picture is taken at this time. When the half-push switch 8 is turned off, the process returns from S213 to the flowchart shown in FIG.

Next, the flow of the photographing process will be further described with reference to FIG. It is possible to take a picture when the charging is completed in the SB light emission mode or in the SB light emission mode.
The processing proceeds from point A in FIG. 3 to point A in FIG. First, S300,
The process goes around the loop of S301, S302, and S303. In S300, it is determined whether or not the autofocus mode is the moving object prediction mode, and when it is the normal autofocus mode, the process proceeds to S302. In the moving object prediction mode, the process proceeds to S301, and the distance measuring process is executed. Since the content of the distance measuring process is the same as that of S201 described above, the description thereof is omitted.

While the release switch 9 is off and the half-push switch 8 is on, S300, S301, S302,
It goes around the loop of S303. In the normal autofocus mode, the switches are simply checked in S302 and S303, but in the moving object prediction mode, the distance measurement processing is repeated in S301 with the confirmation of the switches, and the distance measurement results are continuously accumulated. When it is confirmed in S303 that the half-push switch 7 is off, S311 to S in the flowchart shown in FIG.
Return to 100. In this case, shooting is not performed.

When it is confirmed in S302 that the release switch 9 is on, the process proceeds to S304. In S304, it is determined whether or not the moving object prediction mode is set. If the normal autofocus mode is not the moving object prediction mode, the process proceeds from S304 to S306. In the moving object prediction mode, the process proceeds to S305 and S301.
The subject distance at the time of opening the shutter is predicted and calculated on the basis of the distance measurement result in (1). Although details of the prediction calculation are omitted, when the continuous distance measurement results immediately before confirming that the release switch 9 is turned on are gradually approaching the short distance, at the time of the release, the distance is further closer than the last distance measurement value. Predict that there is a subject and find the distance. On the contrary, when the immediately preceding continuous distance measurement result is gradually moving to a long distance, the distance is calculated by predicting that the subject is at a distance farther than the last distance measurement value at the time of release.

Next, the taking lens is driven according to the distance measurement value in S306. As the shooting distance, in the moving body prediction mode, the distance obtained by the moving body prediction calculation in S305 is used.
In the normal autofocus mode other than the moving object prediction mode, the distance measurement result of S201 is used.

Next, in step S307, the shutter is opened and closed.
As the opening time, the value set in any of S203, S208, and S210 is used. When the SB emission mode is set in S205, the SB circuit 6 emits SB in synchronization with the shutter opening. Then, in S308, the taking lens is returned to the initial position. Furthermore, it progresses to S309,
The film is wound up, and waiting for the half-press switch 8 to be turned off in S310, and when it is confirmed that the half-press switch 8 is off, the process returns from S311 to S100 of the flowchart shown in FIG.

Although not shown in the flow chart, the SB circuit starts charging the SB after the SB emission. S
After the B charging is started, the SB charging continues to be confirmed even after returning to the flowchart of FIG. 1 during charging, and the charging is stopped when the charging is completed.

Finally, the moving body prediction mode setting process will be described with reference to FIG. In S104 of FIG.
When it is confirmed that the moving object prediction mode setting switch 10 is on, S
The processing advances to 108, and the moving object prediction mode setting processing shown in S400 of FIG. 4 is called. Then, in S401, it is determined whether or not the moving object prediction mode is set. In the moving object prediction mode, the process proceeds to S403, and the normal autofocus mode is set. On the other hand, if it is determined in S401 that the normal autofocus mode is selected, the process proceeds to S402, and the moving object prediction mode is set.

Next, in S404, the set mode is displayed on the LCD 3. Then, it progresses to S405 and waits until the moving body prediction mode setting switch 10 is turned off. When the moving object prediction mode setting switch 10 is turned off, S
The process proceeds from 406 to S100 of FIG.

In the above embodiments, the camera having the moving object predicting function has been described, but the present invention can be applied to the camera having no moving object predicting function. The flow of the photographing process in that case may be the one in which S207 of FIG. 2 is omitted. That is, this is equivalent to the flow in which the distance measurement is performed in S206 of FIG. 2, and when the result is a long distance, the process directly proceeds to S209 without passing through S207. Further, in the present embodiment, the SB light emission mode is set when it is determined from the result of photometry that the brightness is low, but the present invention is not limited to this, and the ON / OFF determination of the light emission mode setting SW (not shown)
The SB emission mode may be set. The flow of processing in that case is based on the change of S204 in FIG. 2 to "light emission mode SWON?".

In the above embodiments, the camera in which the moving body prediction mode is set by the photographer using the moving body prediction mode setting switch 10 to determine that the subject is a moving body has been described. However, the present invention is not limited to this, and can also be applied to a camera in which the camera determines that the subject is a moving object from the distance measurement result and the autofocus mode is automatically switched to the moving object prediction mode. .. That is, it is meant to include both the case where the setting of the moving object prediction mode is made by the photographer and the case where the camera itself is made.

Furthermore, although the SB built-in type camera has been described in the above embodiments, the present invention is not limited to this.
The present invention can also be applied to a camera having a function, for example, a camera in which the SB is detachable.

Furthermore, the present invention can be applied to a single-lens reflex camera. In that case, the first time limit is 1/12
From the range of 5 to 1/250 seconds, and the second time limit is 1
It can be selected from the range of / 30 to 1/60 seconds.

[0039]

As described above, according to the first aspect of the present invention, the exposure amount necessary for photographing is secured even in the SB light emission mode and even when the distance measurement result is that strobe light does not reach farther than a predetermined distance. be able to.

According to a second aspect of the present invention, in the SB light emission mode and the distance measurement result is farther than a predetermined distance,
When the subject is moving, it is possible to suppress the occurrence of subject blurring by prohibiting the process of setting the shutter opening limit time longer than the predetermined time.

[Brief description of drawings]

FIG. 1 is a flowchart showing a flow of overall processing of a camera according to the present invention.

FIG. 2 is a flowchart showing a first half of a shooting process of the camera of the embodiment.

FIG. 3 is a flowchart showing the latter half of the shooting process of the camera of the embodiment.

FIG. 4 is a flowchart showing a moving body prediction mode setting process of the camera of the embodiment.

FIG. 5 is a block diagram showing a main circuit part of the camera according to the embodiment.

[Explanation of symbols]

 2 CPU 4 Photometric circuit 5 Distance measuring circuit 6 SB circuit 7 Main switch 8 Half-press switch 9 Release switch 10 Motion prediction mode setting switch

Claims (3)

[Claims] 1. A camera having a distance measuring means and capable of stroboscopic photographing, setting means for setting stroboscopic photographing, and whether the distance measuring result by the distance measuring means is longer than a predetermined distance when the stroboscopic photographing is set by the setting means. When it is judged to be close by the judgment means for judging whether or not it is close, the shutter synchronization time is set to the first second, and when it is judged to be far, the shutter synchronization time is set to the first. A camera having a second time setting means for setting a second time longer than the second time. 2. A camera having distance measuring means and capable of stroboscopic photography, setting means for setting stroboscopic photography, and strobe synchronization time of a first second and a second time longer than the first second. A synchronization time setting means for setting time, a moving body detection means for detecting whether or not a subject is moving, and a strobe shooting setting by the setting means, according to the output of the moving body detection means And a prohibition means for prohibiting setting the shutter synchronization time to the second time. 3. A moving object predicting mode for setting a moving object predicting mode for predicting a position of a subject at the time of opening a shutter to determine a shooting distance by continuously measuring a distance, and the moving object predicting mode by the mode setting means. 3. The camera according to claim 2, wherein the moving body detection means performs a detection operation when is set.