JP2011164244A - Imaging apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately control the photographic conditions, according to prioritizing in either the image quality or power consumption, or by taking into consideration the exposure states of both subjects in a close-range view and a distant view. <P>SOLUTION: A CPU 11 specifies light-emitting time of a flash, in a state of maintaining shutter speed and diaphragm value specified, when the flash is not made to emit light, based on brightness measured by making the flash preliminarily emit light. Also, when an image quality priority mode is set, the CPU 11 adjusts the photographing sensitivity and the light-emitting time of the flash by prioritizing the maintenance of the photographing sensitivity specified so that occurring noise is equal to or under the predetermined size; and when the mode is to a power consumption priority mode, the CPU adjusts the photographing sensitivity and the light emitting time of the flash, by prioritizing the maintenance of the flashlight to predetermined light-emitting characteristics. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and a program.

  Conventionally, with digital cameras, when shooting in dark places such as night shooting, it is necessary to adjust exposure parameters so that the subject appears brighter by adjusting various shooting parameters. Therefore, there is a problem in that it cannot be corrected beyond the brightness of the lens, and camera shake tends to occur if the shutter speed is set too low. For this reason, when exposure correction of a certain level or more is required, shooting is performed by increasing the shooting sensitivity or by emitting a flash.

  As described above, there are various problems even when shooting sensitivity is increased or the flash is fired.For example, when the flash is not flashing, the upper limit of the shooting sensitivity adjustment range is not limited. There has been proposed a technique for preventing the emission color from becoming unstable when the flash emission time is short by limiting the upper limit of the sensitivity adjustment range so that the flash emission time is not too short (for example, Patent Document 1).

Japanese Patent Laid-Open No. 2007-025558

  By the way, there is a problem that if the shooting sensitivity is increased too much, noise increases and the image quality of the shot image decreases, and if the flash emission amount is increased, the power consumption increases and the battery life decreases.

  Also, depending on whether the main subject is a distant view or a close-up view, or both, it is possible to change the shutter speed, aperture value, or flash firing time to adjust the exposure to achieve optimal shooting. Come.

  However, in the above prior art, the shooting sensitivity and flash emission amount are controlled in consideration of the balance between image quality and battery life, and the exposure conditions are controlled in consideration of whether the main subject is a distant view or a foreground. There was a problem that could not be done.

  SUMMARY An advantage of some aspects of the invention is that it provides an imaging apparatus and a program that can appropriately adjust exposure conditions in consideration of various conditions such as image quality and power consumption, and near and distant views.

  In order to achieve the above object, the invention according to claim 1 is based on the first measuring means for measuring the brightness of the subject without emitting the flash, and the brightness measured by the first measuring means. First exposure control means for specifying a shutter speed and an aperture value so that the subject brightness is appropriate when the flash is not emitted, and the subject brightness is measured with the flash pre-flashed Based on the second measuring means and the brightness measured by the second measuring means, the brightness of the subject is maintained while maintaining the shutter speed and aperture value specified by the first exposure control means. An image pickup apparatus comprising: a second exposure control unit that specifies the flash emission time to be appropriate.

  According to a second aspect of the present invention, in the imaging apparatus according to the first aspect, the image pickup apparatus further includes a setting unit that sets one of an image quality priority mode and a power consumption priority mode, and the second exposure control unit includes: In the case where the image quality priority mode is set by the setting means, the brightness of the subject is given priority by maintaining the shooting sensitivity at the first shooting sensitivity specified so that the generated noise is equal to or lower than a predetermined value. If the shooting sensitivity and the flash emission time are adjusted so as to be appropriate, and the power consumption priority mode is set by the setting means, priority is given to maintaining the flash light at a predetermined emission characteristic. Then, it is characterized by adjusting the photographing sensitivity so that the brightness of the subject is appropriate and the flash emission time.

  According to a third aspect of the present invention, in the imaging apparatus according to the second aspect, the second exposure control unit is further required based on the brightness measured by the second measurement unit. A flash emission time is specified, and when the specified flash emission time is equal to or less than a preset first emission time, the flash emission time at the time of shooting is set as the specified flash emission time. And when the specified flash emission time is between the first emission time and a preset second emission time, the flash emission time is fixed at the first emission time. In this state, the exposure sensitivity is changed by changing the imaging sensitivity within the range from the first imaging sensitivity to the second imaging sensitivity that is the maximum value of the imaging sensitivity, and the specified flash emission time is Second When the flashing time is exceeded, exposure correction is performed by changing the flashing flash time within a range equal to or longer than the second flashing time with the shooting sensitivity fixed at the second shooting sensitivity. It is characterized by.

  Further, as in claim 4, in the imaging apparatus according to claim 3, the second exposure control means further determines whether the image quality priority mode or the power consumption priority mode is set by the setting means. Accordingly, the first and second light emission times are set to different values, and the first and second cases where the image quality priority mode is set than when the power consumption priority mode is set are set. The emission time is set to be long.

  Further, as described in claim 5, in the imaging device according to claim 1, based on the brightness measured by the first measuring unit or the brightness measured by the second measuring unit, It further comprises third exposure control means for specifying the shutter speed, aperture value, and flash emission time so that the brightness of the subject is appropriate.

  Further, as described in claim 6, in the imaging device according to claim 5, one of a selection priority mode in which priority is given to one of the foreground and the background and a priority mode in which priority is given to both the foreground and the background is selected. A second setting means for setting, and when both priority modes are set by the second setting means, the exposure condition is set by the first exposure control means and the second exposure control means; When the selection priority mode is set by the second setting means, the exposure condition is set by the third exposure control means.

  According to a seventh aspect of the present invention, in the imaging device according to the sixth aspect, the third exposure control unit is configured such that the selection priority mode that prioritizes the near view is set by the second setting unit. Specifies the shutter speed, the aperture value, and the flash emission time so that the brightness of the subject is appropriate based on the brightness measured by the second measuring means, and the second setting means When the selection priority mode that prioritizes distant views is set, the shutter speed, aperture value, and the like so that the brightness of the subject is appropriate based on the brightness measured by the first measuring means. The light emission time of the flash is specified.

  In order to achieve the above object, the invention described in claim 8 is measured by a first measurement function for measuring the brightness of a subject in a state where the flash is not emitted to a computer of the imaging apparatus, and the first measurement function. A first exposure control function for specifying a shutter speed and an aperture value so that the brightness of the subject is appropriate when the flash is not emitted based on the brightness of the subject, the subject with the flash preliminarily emitted In a state where the shutter speed and the aperture value specified by the first exposure control function are maintained based on the second measurement function for measuring the brightness of the first exposure control function based on the brightness measured by the second measurement function. A program for realizing a second exposure control function for specifying a flash emission time so that the brightness of an object is appropriate.

  According to a ninth aspect of the present invention, in the program according to the eighth aspect, a setting function for setting either the image quality priority mode or the power consumption priority mode is further realized, and the second exposure control function is When the image quality priority mode is set by the setting function, the brightness of the subject is given priority by maintaining the shooting sensitivity at the first shooting sensitivity that is defined so that the generated noise is equal to or lower than a predetermined value. If the shooting sensitivity and the flash emission time are adjusted to be appropriate, and the power consumption priority mode is set by the setting function, priority is given to maintaining the flash light at the predetermined emission characteristics. Then, it is characterized by adjusting the photographing sensitivity so that the brightness of the subject is appropriate and the flash emission time.

  Further, in the program according to claim 8, the subject according to claim 8, based on the brightness measured by the first measurement function or the brightness measured by the second measurement function. A third exposure control function for specifying the shutter speed, the aperture value, and the flash emission time so that the brightness of the image becomes appropriate is further realized.

  In addition, as described in claim 11, in the program according to claim 10, one of a selection priority mode in which priority is given to one of the foreground and the background and a priority mode in which priority is given to both the foreground and the background is set. The second setting function is further realized, and when the two priority mode is set by the second setting function, the exposure condition is set by the first exposure control function and the second exposure control function. And when the selection priority mode is set by the second setting function, the exposure condition is set by the third exposure control function.

  According to the present invention, it is possible to obtain an advantage that exposure conditions can be appropriately adjusted in consideration of various conditions such as image quality and power consumption, and foreground and background.

It is a block diagram which shows the structure of the digital camera by 1st Embodiment of this invention. It is a conceptual diagram for demonstrating the setting of the imaging condition by the digital camera of this 1st Embodiment. FIG. 3 is a conceptual diagram showing the light emission characteristics of a xenon tube which is one of the light sources used in the flash light emitting unit 18 according to the first embodiment. It is a conceptual diagram for explaining the setting of the photographing conditions set in consideration of the light emission characteristics of the xenon tube. 4 is a flowchart for explaining the operation of the digital camera according to the first embodiment. 4 is a flowchart for explaining the operation of the digital camera according to the first embodiment. It is a flowchart for demonstrating operation | movement of the digital camera by this 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

A. First embodiment A-1. Configuration of First Embodiment FIG. 1 is a block diagram showing a configuration of a digital camera according to a first embodiment of the present invention. In the figure, a digital camera 1 includes a photographic lens 2, a lens driving block 3, a diaphragm shutter 4, a CCD 5, and a TG (timing
generator) 6, unit circuit 7, image processing unit 8, CPU 11, DRAM 12, memory 13, flash memory 14, image display unit 15, key input unit 16, flash drive unit 17, flash light emitting unit 18, and card I / F 19 In the card I / F 19, a memory card 20 is detachably mounted in a card slot (not shown) of the digital camera 1 main body.

  The photographing lens 2 includes a focus lens and a zoom lens (not shown), and a lens driving block 3 is connected thereto. The lens driving block 3 includes a motor for driving a focus lens and a zoom lens (not shown) in the optical axis direction, a focus motor driver for driving the focus motor and the zoom motor in the optical axis direction according to a control signal from the CPU 11, and a zoom motor, respectively. Consists of drivers.

  The diaphragm 4 includes a drive circuit (not shown), and the drive circuit operates the diaphragm 4 in accordance with a control signal sent from the CPU 11. The diaphragm 4 controls the amount of light that enters from the taking lens 2. The digital camera according to the first embodiment includes an electronic shutter mechanism (not shown), and controls the time for which light is applied to the CCD 5 by the electronic shutter mechanism. Exposure can be determined by this aperture and shutter speed.

  A CCD (imaging device) 5 converts light of a subject projected via the photographing lens 2, the diaphragm 4, and an electronic shutter mechanism (not shown) into an electrical signal and outputs the electrical signal to the unit circuit 7. The CCD 5 is driven according to a timing signal having a predetermined frequency generated by the TG 6.

The unit circuit 7 is a CDS (Correlated) that holds the imaging signal output from the CCD 5 by correlated double sampling.
Double Sampling) circuit, AGC (Automatic) for automatic gain adjustment of the imaged signal after sampling
(Gain Control) circuit and an A / D converter for converting an analog image pickup signal after the automatic gain adjustment into a digital signal. The imaging signal of the CCD 5 is sent to the image processing unit 8 as a digital signal through the unit circuit 7. The unit circuit 7 is connected to the TG 6.

  The image processing unit 8 performs image processing (pixel interpolation processing, γ correction, luminance color difference signal generation, white balance processing, exposure correction processing, etc.) of image data sent from the unit circuit 7, and compression / decompression of image data ( For example, JPEG format, M-JPEG format, or MPEG format compression / decompression processing, and information necessary for the smear removal processing unit 8 (horizontal OB address information, vertical OB address information, etc.) are output. Note that a TG 6 is connected to the image processing unit 8. The photometry circuit 9 measures the brightness of the subject and supplies it to the CPU.

  The CPU 11 is a one-chip microcomputer that controls each part of the digital camera 1. In particular, in the first embodiment, the CPU 11 performs preliminary light emission of the flash light emitting unit 18, light emission at the time of photographing, measurement of subject brightness by the photometry circuit 9, shutter speed for optimizing subject brightness, And aperture value setting, setting / adjustment of the light emission time (light emission amount) of the flash light-emitting unit 18 according to the operation mode (image quality priority or power consumption priority), backlight shooting or forced flash mode, or foreground or distant priority It is designed to specify shooting conditions (flash emission time, shooting sensitivity, shutter speed, aperture value) according to certain conditions, shooting operations under the set shooting conditions, and the like.

  The DRAM 12 is used as a buffer memory for temporarily storing image data sent to the CPU 11 after being imaged by the CCD 5 and also as a working memory for the CPU 11. The memory 13 stores a program necessary for controlling each part of the digital camera 1 by the CPU 11 and data necessary for controlling each part, and the CPU 11 performs processing according to this program. The flash memory 14 and the memory card 20 are recording media for storing image data captured by the CCD 5.

  The image display unit 15 includes a color LCD and its drive circuit, and displays the subject imaged by the CCD 5 as a through image when in the shooting standby state, and when reproducing the recorded image, the storage flash memory 14 and the memory card. The recorded image read out from 20 and expanded is displayed. The key input unit 16 includes a plurality of operation keys such as a shutter button, a mode key, a SET key, and a cross key, and outputs an operation signal corresponding to the user's key operation to the CPU 11.

  The flash drive unit 17 drives the flash light emitting unit 18 to flash according to the control signal of the CPU 11, and the flash light emitting unit 18 flashes the flash. The CPU 11 determines whether or not the shooting scene is dark by the photometry circuit 9, determines that the shooting scene is dark, and determines that shooting is to be performed (when the shutter button is pressed), the CPU 11 controls the flash drive unit 17. Send a signal.

  FIGS. 2A and 2B are conceptual diagrams for explaining setting of photographing conditions by the digital camera of the first embodiment. FIG. 2A shows the relationship between the shooting sensitivity and the flash emission time when shooting with priority on image quality. FIG. 2B shows the relationship between shooting sensitivity and flash emission time when shooting is performed with priority on power consumption.

  A is a specified value of the shooting sensitivity (first specified value: first shooting sensitivity) for obtaining a noise-free image. When the shooting sensitivity is further increased, the noise gradually increases. Even if the shooting sensitivity is lowered below, the shooting sensitivity is such that the appearance image quality is hardly deteriorated. B is the maximum value of the shooting sensitivity (second specified value: second shooting sensitivity). If the shooting sensitivity is further increased, the shooting sensitivity is such that the amount of noise increases to an unpractical level. It is.

  C is the minimum value of the light emission time required until the emission color of the xenon tube is stabilized, or the minimum value of the light emission time required for the increase in the light emission amount with respect to the increase in the light emission time to fall within the specified range. D is a light emission time in which the light emission amount of the xenon tube is maximized.

  It is possible to control the shooting sensitivity and the flash time so that the image quality and the power consumption level are always the same. However, in such a control, the priority is given to either the image quality or the power consumption. It becomes control. Therefore, in the present invention, two operation modes of an image quality priority mode and a power consumption priority mode are provided. In the image quality priority mode, the flash exposure characteristic shown in FIG. 2A is used, and in the power consumption priority mode, FIG. Using the flash exposure characteristics shown, control is performed to clarify which of image quality and power consumption is prioritized.

  Here, FIG. 3 is a conceptual diagram showing the light emission characteristics of a xenon tube which is one of the light sources used in the flash light emitting unit 18 according to the first embodiment. Strictly speaking, as shown in FIG. 3, the xenon tube has a light emission characteristic in which a sufficient amount of light cannot be expected immediately after the start of light emission and in the vicinity of the end of light emission. Therefore, an example in which the range immediately after the start of light emission and the range excluding the vicinity of the end of light emission is used as the use range will be described below.

  FIGS. 4A and 4B are conceptual diagrams for explaining the setting of photographing conditions set in consideration of the light emission characteristics of the xenon tube described above. FIG. 4A shows flash exposure characteristics when shooting with priority on image quality. FIG. 4B shows flash exposure characteristics when shooting with priority on power consumption.

  In the figure, A to D are the same as FIGS. 2 (a) and 2 (b). E is the maximum value of the light emission time required for the increase in the light emission amount with respect to the increase in the light emission time to be within the specified range, or the light emission necessary for suppressing the difference in the light emission amount due to the variation in solids of the xenon tube to a predetermined value or less. This is the maximum value of time (second light emission time). F is the maximum value of the light emission time required to suppress the power consumption due to light emission of the xenon tube within a specified value (first light emission time).

  As described above, when a light emitting element whose light emission characteristics are deteriorated in a region where the light emission time is too long or too short, such as a xenon tube, is used for the flash light emitting unit 18 in FIG. The flash exposure characteristic shown in FIG. 4 is used, and in the power consumption priority, the flash exposure characteristic shown in FIG. 4B is used to control whether the image quality or the power consumption is given priority, and the emission color. And stabilize the amount of luminescence.

A-2. Operation of First Embodiment Next, the operation of the first embodiment described above will be described. In the following, description will be made using the flash exposure characteristics shown in FIGS.

  5 and 6 are flowcharts for explaining the operation of the digital camera according to the first embodiment. When the photographing mode is entered, first, the photographing sensitivity is set to the first specified value (A in FIGS. 4A and 4B) with less noise generation (step S10), and the flash light emitting unit 18 is not turned on. Then, the entire brightness including the distant view portion where the flash light is difficult to reach is measured (step S12). Next, based on the measured brightness, a shutter speed and an aperture value are set so as to optimize the overall brightness including a distant view portion where the flash light is difficult to reach (step S14). However, the shutter speed is limited to a range where there is little camera shake.

  Next, it is determined whether the light amount is insufficient based on the shutter speed and the aperture value (step S16). If the light amount is not insufficient, it is determined whether the backlight shooting or the forced light emission mode is set. (Step S18). When the amount of light is insufficient, or when the backlight shooting or the forced light emission mode is selected, the flash light emitting unit 18 is preliminarily emitted twice with different light emission amounts, so that the near-field portion where the flash light easily reaches is mainly used. The degree of brightness change with respect to the flash light quantity change is measured (step S20). Next, assuming that the shooting sensitivity, shutter speed, and aperture value are set, the brightness of the foreground part where the flash light is easy to reach is appropriate based on the degree of change in the measured brightness. The light emission time (light emission amount) to be changed is specified (step S22).

  Next, it is determined whether the operation mode is image quality priority or power consumption priority (step S24). If the image quality priority is given, the light emission characteristic is maintained at a predetermined state at the light emission time switching point. Is set to a predetermined light emission time (step S26). That is, the flash exposure characteristic shown in FIG. In this case, the switching point of the light emission time is “E”.

  On the other hand, if power consumption is prioritized, the light emission time switching point is set to a predetermined light emission time so that the power consumption is within a predetermined range (step S28). That is, the flash exposure characteristic shown in FIG. In this case, the switching point of the light emission time is “F”.

  Next, in both cases of steps S26 and S28, it is determined whether or not the light emission time specified in step S22 exceeds the switching point (E, F) set in step S26 or step S28 ( In step S30), if the specified light emission time exceeds the switching point (E, F), the light emission time is within the switching point by changing the photographing sensitivity to the second specified value (B) that generates a lot of noise. It is determined whether or not it is possible to fit in (step S32).

  If the shooting sensitivity is changed to the second specified value (B) where noise is generated frequently, the flashing time can be kept within the switching points (E, F). The imaging sensitivity is readjusted while being fixed at (E, F) (step S34).

  On the other hand, if it is impossible to keep the light emission time within the switching points (E, F) even if the shooting sensitivity is changed to the second specified value (B), which generates a lot of noise, the shooting sensitivity is changed to the first setting. The light emission time is readjusted while being fixed at the specified value (B) of 2 (step S36).

  Next, in both cases of steps S34 and S36, the main photographing is performed under the set photographing conditions (step S38).

  If it is determined in step S18 that the backlight shooting mode or the forced flash mode is not set, or if the specified emission time does not exceed the set switching point (E, F) in step S30, the setting is made in step S14. The main photographing is performed according to the photographing conditions (step S38).

According to the first embodiment described above, since the switching point of the light emission time is changed by selecting the image quality priority mode and the power consumption priority mode, the photographing sensitivity and the flash are changed according to which of the image quality and the power consumption is prioritized. The light emission time can be appropriately controlled.
For distant views, exposure adjustment is performed mainly by changing the shutter speed and aperture value. For close-up views, the flash emission time is mainly maintained with the shutter speed and aperture value set for the distant view being maintained. (Adjusting the exposure sensitivity in the power saving mode) adjusts the exposure so that both the foreground and distant views are appropriate regardless of whether the image quality priority mode or power consumption priority mode is set. Exposure adjustment can be performed so that the brightness is achieved.

B. Second Embodiment Next, a second embodiment of the present invention will be described.
In the first embodiment, exposure adjustment is performed mainly by changing the shutter speed and aperture value for the far view so that both the foreground and the distant view have appropriate brightness, and the foreground is set according to the distant view. The exposure adjustment was performed mainly by changing the flash emission time (while changing the shooting sensitivity in the power saving mode) while maintaining the shutter speed and aperture value.

  In this case, the shutter speed and aperture value are already adjusted so that the maximum brightness can be obtained in a range where there is little camera shake when the flash is fired due to insufficient light in the distant view. If you adjust the shooting conditions of the foreground while maintaining the shutter speed and aperture value set according to, there is no problem, for example, the amount of light in the foreground is not insufficient, but the subject in the foreground is prevented from becoming dark due to backlighting For this reason, an unnecessarily high shutter speed or an unnecessarily dark aperture value may be set when the flash is fired. The light emission time becomes long and extra power is consumed.

  Therefore, in the second embodiment, when only one of the foreground and the foreground needs to be considered, the shutter speed and aperture value for the foreground, the flash emission time for the foreground, etc., and the shooting adjusted for the foreground and foreground. Without separating the parameters, the shutter speed, aperture value, and flash emission time are all adjusted simultaneously according to the measured brightness.

  The configuration of the digital camera itself is the same as that shown in FIG.

  FIG. 7 is a flowchart for explaining the operation of the digital camera according to the second embodiment. Note that the same steps as those in the first embodiment are omitted. When the photographing mode is entered, first, the photographing sensitivity is set to the first specified value with less noise generation (step S10), and the entire brightness including the distant view portion where the flash light is difficult to reach without the flash light emitting unit 18 emitting light. The thickness is measured (step S12). Next, based on the measured brightness, a shutter speed and an aperture value are set so as to optimize the overall brightness including a distant view portion where the flash light is difficult to reach (step S14). However, the shutter speed is limited to a range where there is little camera shake.

  Next, it is determined whether the light amount is insufficient based on the shutter speed and the aperture value (step S50). If the light amount is insufficient, it is determined whether the backlight photographing mode or the forced light emission mode is set. (Step S52) In the case of backlighting or forced light emission mode, it is determined whether the near distance is set as the priority distance or the far view is set as the priority distance (Step S54).

  Then, when the light amount is insufficient, when the backlight shooting or the forced light emission mode is not used, or when both the near view and the distant view are considered, the process proceeds to step S20 and later described in the first embodiment. In this case, since the operation is the same as that of the first embodiment, description thereof is omitted.

  On the other hand, when the amount of light is not short, when the backlight shooting mode or the forced flash mode is used, and when the foreground is prioritized, the flash light emitting unit 18 is preliminarily emitted twice with different light emission amounts. The degree of change in brightness with respect to the change in the amount of flash light in the foreground portion where the flash light is easy to reach is measured (step S56). Next, based on the degree of change in the measured brightness, the flash time (light emission level), shooting sensitivity, shutter speed, and aperture value that optimize the brightness of the foreground part where the flash light is easy to reach. Specify (step S58). Then, the main photographing is performed using the light emission time (light emission amount), photographing sensitivity, shutter speed, and aperture value as photographing conditions (step S62).

  On the other hand, when the amount of light is not insufficient in step S50, and in step S52, when the backlight shooting or forced light emission mode is selected and priority is given to a distant view, the measurement was performed without emitting the flash. Based on the overall brightness, the light emission time (light emission amount), the photographing sensitivity, the shutter speed, and the aperture value are specified so as to optimize the overall brightness including the distant view portion where the flash light is difficult to reach (step S60). . Then, the main photographing is performed using the light emission time (light emission amount), photographing sensitivity, shutter speed, and aperture value as photographing conditions (step S62).

  In the second embodiment described above, the light emission time (light emission amount), the shooting sensitivity, the shutter speed, and the aperture value are specified in step S58 when the foreground priority is given and in step S60 when the background is given priority. After that, the process proceeds to the main shooting in step S62. However, the present invention is not limited to this, and as in the first embodiment described above, whether the priority is image quality priority or power consumption priority in each of the foreground priority and the far scene priority. If the image quality is prioritized, priority is given to maintaining the shooting sensitivity at the shooting sensitivity (A) that is defined so that the generated noise is equal to or less than a predetermined value, and the brightness of the subject is appropriate. Adjust the shooting sensitivity and flash emission time, and if power consumption is prioritized, give priority to maintaining the flash light in the predetermined emission characteristics, and the shooting sensitivity that makes the subject brightness appropriate, and Flat Adjust Interview emission time, then, it may proceed to the shooting.

  According to the second embodiment described above, it is possible to adjust the shutter speed, the aperture value, and the flash emission time in consideration of the exposure state of both the foreground and the foreground subjects.

1 Digital Camera 2 Shooting Lens 3 Lens Drive Block 4 Shutter / Shutter 5 CCD
6 TG
7 Unit Circuit 8 Image Processing Unit 9 Photometric Circuit 11 CPU
12 DRAM
13 Memory 14 Flash Memory 15 Image Display Unit 16 Key Input Unit 17 Flash Drive Unit 18 Flash Light Emitting Unit 19 Card I / F
20 Memory card

Claims (11)

First measuring means for measuring the brightness of the subject in a state where the flash is not emitted;
Based on the brightness measured by the first measuring means, a first exposure control means for specifying a shutter speed and an aperture value so that the brightness of the subject is appropriate when the flash is not emitted;
Second measuring means for measuring the brightness of the subject with the flash pre-flashed;
Based on the brightness measured by the second measuring means, the flash is such that the brightness of the subject is appropriate while maintaining the shutter speed and aperture value specified by the first exposure control means. And a second exposure control means for specifying the light emission time. It further comprises setting means for setting either the image quality priority mode or the power consumption priority mode,
The second exposure control means includes
When the image quality priority mode is set by the setting means, the brightness of the subject is given priority to maintaining the shooting sensitivity at the first shooting sensitivity that is defined so that the generated noise is equal to or lower than a predetermined value. Adjust the shooting sensitivity and the flash emission time so that the
When the power consumption priority mode is set by the setting means, the shooting sensitivity that makes the brightness of the subject appropriate, giving priority to maintaining the flash light in a predetermined light emission characteristic, and the flash Adjusting the flash time of
The imaging apparatus according to claim 1. The second exposure control means further specifies a flash emission time required based on the brightness measured by the second measurement means,
When the specified flash emission time is equal to or less than a preset first emission time, the flash emission time at the time of shooting is set as the specified flash emission time,
When the specified flash emission time is between the first emission time and the preset second emission time, the flash emission time is fixed to the first emission time. , Exposure correction is performed by changing the shooting sensitivity within the range from the first shooting sensitivity to the second shooting sensitivity which is the maximum value of shooting sensitivity,
When the specified flash light emission time exceeds the second light emission time, the flash light emission time is set to be equal to or greater than the second light emission time with the photographing sensitivity fixed to the second photographing sensitivity. Exposure compensation by changing within the range of
The imaging apparatus according to claim 2. The second exposure control means further sets the first and second light emission times to different values depending on whether the image quality priority mode or the power consumption priority mode is set by the setting means, The first and second emission times are set to be longer when the image quality priority mode is set than when the power consumption priority mode is set.
The imaging apparatus according to claim 3. Based on the brightness measured by the first measuring means or the brightness measured by the second measuring means, the shutter speed, aperture value, and flash A third exposure control means for specifying the light emission time;
The imaging apparatus according to claim 1. A second setting means for setting either a selection priority mode that prioritizes either the foreground or the far view and a both priority mode that prioritizes both the foreground or the far view;
When the two priority mode is set by the second setting means, the exposure condition is set by the first exposure control means and the second exposure control means,
When the selection priority mode is set by the second setting means, the exposure condition is set by the third exposure control means;
The imaging apparatus according to claim 5. The third exposure control means includes
When the selection priority mode that prioritizes the near view is set by the second setting means, the brightness of the subject is appropriate based on the brightness measured by the second measurement means. Identify the shutter speed, aperture value, and flash duration,
When the selection priority mode that prioritizes distant views is set by the second setting means, the brightness of the subject is appropriate based on the brightness measured by the first measurement means. Specify the shutter speed, aperture value, and flash duration.
The imaging apparatus according to claim 6. In the computer of the imaging device,
A first measurement function for measuring the brightness of the subject without flash
A first exposure control function for specifying a shutter speed and an aperture value based on the brightness measured by the first measurement function so that the brightness of the subject is appropriate when the flash is not emitted;
A second measuring function for measuring the brightness of the subject with the flash pre-flashed;
On the basis of the brightness measured by the second measurement function, the flash is set so that the brightness of the subject is appropriate while maintaining the shutter speed and the aperture value specified by the first exposure control function. A program for realizing a second exposure control function for specifying a light emission time. Further realize the setting function to set either the image quality priority mode or the power consumption priority mode,
The second exposure control function is:
When the image quality priority mode is set by the setting function, the brightness of the subject is given priority by maintaining the shooting sensitivity at the first shooting sensitivity that is defined so that the generated noise is equal to or lower than a predetermined value. Adjust the shooting sensitivity and the flash emission time so that the
In the case where the power consumption priority mode is set by the setting function, the shooting sensitivity that makes the brightness of the subject appropriate, giving priority to maintaining the flash light in a predetermined light emission characteristic, and the flash Adjusting the flash time of
The program according to claim 8. Based on the brightness measured by the first measurement function or the brightness measured by the second measurement function, the shutter speed, aperture value, and flash Further realizing a third exposure control function for specifying the light emission time,
The program according to claim 8. Further realizing a second setting function for setting either a selection priority mode that gives priority to either the foreground or the far view and a priority mode that gives priority to both the foreground or the far view,
When both priority modes are set by the second setting function, the exposure condition is set by the first exposure control function and the second exposure control function,
When the selection priority mode is set by the second setting function, the exposure condition is set by the third exposure control function;
The program according to claim 10.

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