JP2003298933A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera to properly increase the gain to meet the photographing intension of a photographer and to select a proper strobe and increase the gain meeting the photographing intention of the photographer. <P>SOLUTION: When the photographer makes a photographing instruction, the digital camera measures the lightness of an object to calculate a BV value. Succeedingly the digital camera sets a reference zoom ratio in response to a set photographing mode and selects a strobe in use depending on the reference zoom ratio and the set zoom ratio. Then the digital camera sets upper limit sensitivity depending on the set photographing mode to select the sensitivity depending on the BV value mentioned above within a range of the upper limit sensitivity. Further, the digital camera actually photographs an object on the basis of the selected strobe and sensitivity. Thus, the digital camera fulfill the above purpose. <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 a digital camera suitable for taking a picture suitable for a photographer's intention of photographing.

[0002]

2. Description of the Related Art In a digital camera, the brightness of an object is measured through an image sensor or a dedicated photometric device before exposure, such as after a 1st release operation is performed.
A diaphragm, a shutter speed, and the like are determined according to the subject brightness based on the measurement result, and photographing is performed. Also,
When the measured brightness of the subject is dark, strobe light emission and gain increase of the output signal from the image sensor are appropriately performed. For example, for a distant subject, the strobe light may not reach sufficiently and sufficient subject brightness may not be obtained. Therefore, when sufficient subject brightness cannot be obtained with such strobe light alone, the gain of the output signal from the image sensor is appropriately increased.

Incidentally, among such digital cameras,
Some cameras are configured so that a fixed mode in which the gain is fixed and an automatic gain mode in which the gain is automatically increased when the measured brightness of the subject is dark are selectable. In a digital camera equipped with a zoom function, the angle of view changes depending on the zoom ratio.
It is not easy to cover the entire focal range with one strobe. Therefore, some digital cameras equipped with a high-magnification zoom function have two types of strobes with different light distribution characteristics, that is, a light distribution characteristic mainly suitable for a wide-side zoom ratio (illumination range (illumination angle range) It has a strobe with a wide range but a short reach of light) and a strobe with a light distribution characteristic (a narrow illumination range but a long reach of light) mainly suitable for the zoom ratio on the tele side. There is also one configured to be able to correspond to the entire focus range according to.

[0004]

By the way, since the above-described gain increase deteriorates the S / N ratio, it is not preferable to increase the gain unnecessarily, and an appropriate gain should be set. However, it is not easy to properly select the gain to be set, and for example, it indicates the photographer's shooting intention such as image quality priority setting, camera shake prevention setting, high shutter speed priority setting, etc. The selection is different depending on the setting. So, from such circumstances,
There is a demand for a digital camera in which an appropriate gain is set according to the photographer's intention of photographing.

Further, in the above-mentioned digital camera having two kinds of strobes having different light distribution characteristics, the selection of the strobe to be used is uniformly determined according to the zoom ratio.
For example, when the zoom ratio is set to the tele side and the strobe suitable for the above-mentioned tele side zoom ratio is uniformly controlled, the wide side is set when the zoom ratio is set to the tele side. It is not possible to fire a flash suitable for the zoom ratio of. Therefore, in the case of this digital camera, when the zoom ratio is on the tele side, it is necessary to reflect the photographing intention of the photographer such as wanting to emit a strobe suitable for the wide side zoom ratio so as not to reduce the amount of peripheral light. I couldn't.

Further, in a digital camera equipped with a strobe (including those equipped with the above-mentioned two types of strobes), a gain setting (gain up for compensating a shortage of luminance as well as strobe emission for a low-luminance object is provided. ) Was uniformly performed based on a certain rule.
Therefore, it is not possible to set an appropriate gain according to the photographer's intention of photographing.

In view of the above situation, an object of the present invention is to provide a digital camera capable of appropriately increasing the gain in accordance with the photographer's intention of photographing, and two types of strobes having different light distribution characteristics. The present invention provides a digital camera capable of selecting an appropriate strobe according to the photographer's shooting intention and performing an appropriate gain increase.

[0008]

The first aspect of the present invention comprises:
An upper limit of the gain is set in accordance with the photographing mode selecting means for selecting the photographing mode and the photographing mode selected by the photographing mode selecting means, and a gain corresponding to the subject brightness is set within a range not more than the upper limit of the gain. The digital camera includes a gain setting unit and a signal level adjusting unit that adjusts the signal level of an image pickup signal based on the gain set by the gain setting unit.

According to the above arrangement, the upper limit of the gain is set according to the photographing mode, and the gain according to the subject brightness is set within that range. The shooting mode refers to a high-sensitivity mode, a portrait mode, or the like, and is used when the photographer reflects his or her intention to shoot. As a result, it is possible to set an appropriate gain according to the photographer's intention of photographing. Note that adjusting the signal level of the image pickup signal means, for example, adjusting the signal level of an analog electric signal which is an output signal from the image pickup element, or image data which is a digital electric signal based on the output signal from the image pickup element. On the other hand, predetermined image processing is performed.

According to a second aspect of the present invention, in the first aspect, the gain setting means selects another mode when a photographing mode giving priority to image quality is selected by the photographing mode selecting means. In this configuration, the upper limit of the gain is set lower than in the case of

According to this structure, when the photographing mode which gives priority to the image quality is selected, the upper limit of the gain is set lower than when the other modes are selected. The image capturing mode in which the image quality is prioritized is, for example, the portrait mode. As a result, it is possible to reflect the photographing intention of the photographer who prioritizes the image quality.

A third aspect of the present invention, in the first or second aspect, further comprises an upper limit instructing means for instructing the upper limit of the gain, and the gain setting means is configured to instruct the upper limit instructing means to set the upper limit of the gain. Is instructed, the upper limit of the gain instructed by the upper limit instruction means is set regardless of the photographing mode selected by the photographing mode selection means.

According to this structure, the upper limit of the gain designated by the upper limit designating unit is preferentially set. Thereby, for example, by the photographer designating the upper limit of the gain, it is possible to set the gain that reflects the photographing intention of the photographer. A fourth aspect of the present invention is a zoom ratio instructing means for instructing a zoom ratio of a zoom photographing optical system,
A photographing mode selecting means for selecting a photographing mode, a first flashing means, a second flashing means having a light distribution characteristic narrower than that of the first flashing means, and a zoom ratio designated by the zoom ratio designating means. And a selection unit that selects either the first flash unit or the second flash unit according to the shooting mode selected by the shooting mode selection unit.

According to the above arrangement, the first or second flash means is selected according to the instructed zoom ratio and the selected photographing mode. This makes it possible to select an appropriate flashing means according to the photographer's intention of photographing. According to a fifth aspect of the present invention, in the fourth aspect, the selecting means sets a reference zoom ratio as a reference according to the shooting mode selected by the shooting mode selecting means, and the set reference zoom is set. The ratio is compared with the zoom ratio instructed by the zoom ratio instructing means, and either the first flashing means or the second flashing means is selected.

According to this structure, the reference zoom ratio, which is a criterion for determining which flash unit to select, is set according to the selected photographing mode. This makes it possible to set an appropriate reference zoom ratio according to the photographer's intention of photographing. According to a sixth aspect of the present invention, in the fourth or fifth aspect, an upper limit of gain is set according to the photographing mode selected by the photographing mode selection means, and the object within the range of the upper limit of gain or less is set. The configuration further includes a gain setting unit that sets a gain according to the brightness, and a signal level adjusting unit that adjusts the signal level of the image pickup signal based on the gain set by the gain setting unit.

According to this structure, the upper limit of the gain is set according to the photographing mode, and the gain according to the subject brightness is set within that range. As a result, it is possible to set an appropriate gain according to the photographer's intention of photographing. According to a seventh aspect of the present invention, a zoom ratio designating means for designating a zoom ratio of a zoom photographing optical system, a first flashing means, and a second light distribution characteristic narrower than that of the first flashing means.
The flash unit and the flash unit to be used are automatically selected in accordance with the zoom ratio instructed by the zoom ratio instruction unit, and in accordance with the instruction regardless of the zoom ratio. Manual strobe mode,
And a mode selecting means for selecting any one of the above.

According to the above arrangement, when the selected mode is the auto flash mode, the flash unit to be used is automatically selected according to the instructed zoom ratio,
When the selected mode is the manual strobe mode, the flashing means to be used is selected according to the instruction (according to the instructed flashing means). Thus, for example, when the photographer designates any one of the flashing means in the manual strobe mode, it is possible to select the optimum flashing means for reflecting the shooting intention.

An eighth aspect of the present invention is a zoom ratio indicating means for instructing a zoom ratio of a zoom photographing optical system, a first flash means, and a light distribution characteristic narrower than that of the first flash means. 2 flashing means, a selecting means for selecting either the first flashing means or the second flashing means in accordance with the zoom ratio designated by the zoom ratio designating means, and selection by the selecting means. The digital camera is provided with an instructing unit for instructing a reference zoom ratio as a reference for switching.

According to the above arrangement, one of the flashing means is selected according to the designated reference zoom ratio. Thus, for example, the photographer can select a flash unit suitable for the photographing intention by instructing the optimum reference zoom ratio for reflecting the photographing intention.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration example of a digital camera according to an embodiment of the present invention. In the figure, the photographing lens unit 1 is configured to include a zoom lens unit (zoom photographing optical system) 2 and a focusing lens unit 3 corresponding to a zoom ratio of 1 × (equal magnification) to 8 ×,
A subject image is formed on the image sensor 4.

The image pickup device 4 is, for example, a CCD (Charge Cou
pled Device), the subject lens image formed on the image pickup device 4 is photoelectrically converted by the action of the taking lens unit 1 and an analog electric signal (image pickup signal) expressing the image is output. The imaging unit 5 uses the CDS (Co
rrelated Double Sampling), A to adjust the signal level
It is configured to include a GC (Automatic Gain Control) and an A / D that converts an analog electric signal into a digital electric signal, and is set while reducing the noise component of the analog electric signal output from the image pickup device 2. The signal level is adjusted based on the gain, and it is converted into a digital electric signal and output.

Further, the image pickup section 5, the DRAM 6, the image processing section 7, the compression / expansion section 8, the LCD display 9, the AF / AE.
The unit 10 and the CPU 11 are both connected to the bus 12 and can exchange data with each other. DRAM
The (Dynamic Random Access Memory) 6 is used for temporarily storing image data, which is a digital electric signal output from the image pickup unit 5, image data being processed in various image processes by the image processing unit 7, or a control process by the CPU 11. Is a memory used as a work area or the like for execution of.

The image processing unit 7 performs various correction processes such as gamma correction and white balance correction performed at the time of recording the image data, and enlarges / enlarges the image for increasing / decreasing the number of pixels forming the image.
Various types of image processing such as reduction processing (resize processing) are performed. The compression / expansion unit 8 performs compression / expansion processing of image data according to the JPEG (Joint Photographic Experts Group) system or the like for recording / reproduction of image data.

The memory card 13 is a recording medium that can be attached to and detached from the digital camera, and records and saves image data representing an image captured by the digital camera. Although not shown, this memory card 1
3 is connected to the compression / expansion unit 8 via the card I / F.

The LCD display 9 displays photographed images represented by image data and various menus.
Although not shown, this LCD display 9
It is connected to the bus 12 via the LCD driver. AF /
The AE unit 10 performs AF (automatic focus adjustment) processing such as obtaining a focus position based on image data based on the output signal of the image sensor 4, and measures the brightness of a subject based on the image data to obtain exposure. AE (automatic exposure) processing such as is performed. In the AE process, the brightness of the subject may be measured using, for example, a dedicated photometric element.

The CPU 11 is a central processing unit and controls the operation of the entire digital camera by executing the camera program stored in the flash memory 14. For example, a process of calculating the subject distance based on the focus position obtained by the AF / AE unit 10 described above is performed.

The flash memory 14 is a non-volatile memory that can be electrically rewritten.
In addition to the camera program executed by the CPU 11, various data used during the execution of the camera program are stored. The drive motor / circuit section 15 includes the CPU 11
The zoom lens unit 2 is driven under the control of.

The drive motor / circuit section 16 drives the focusing lens section 3 under the control of the CPU 11. The strobe control / switching circuit unit 17 selects the strobe A18 or the strobe B19 as the strobe to be used under the control of the CPU 11 and controls the emission of the selected strobe. The strobe is an example of a flash unit.

The strobe A18 is a strobe having a light distribution characteristic mainly suitable for a wide-side zoom ratio, that is, a light distribution characteristic of a wide illumination range (illumination angle range). The strobe A18 is configured to have a light distribution characteristic that can be adapted to a zoom ratio of 1 × (equal magnification) to 6 ×.

The strobe light B19 is a strobe light having a light distribution characteristic mainly suitable for the zoom ratio on the telephoto side, that is, a light distribution characteristic that the light reaches a long distance. The strobe B19 is configured to have a light distribution characteristic that can be adapted to a zoom ratio of 3 to 8 times.

The operating means 20 is a button or the like for receiving various instructions from the photographer and notifying the CPU 11 of the instructions. For example, a release button for enabling an instruction for photographing, a zoom ratio (tele, wide) A zoom button that allows an instruction, a scene switching button that allows an instruction to switch a shooting scene mode (shooting mode), a menu button that allows an instruction to display various setting menus on the LCD display 9, and the like. It should be noted that the photographer can instruct the photographer through the above-mentioned various setting menus about the upper limit of the gain, the automatic strobe mode in which the strobe to be used is automatically selected according to the zoom ratio, and the strobe to be used. Indication of any one of the manual strobe modes, reference zoom ratio indication that serves as a switching reference for the selection of strobes when the above-mentioned automatic strobe mode is instructed (selection criterion), and the aforementioned manual strobe Various instructions such as an instruction of a strobe to be used when the mode is instructed and an instruction to use / not use the strobe can be performed.

In this embodiment, as an instructable shooting scene mode, an auto mode suitable for normal shooting, a high sensitivity mode suitable for high sensitivity shooting, and a portrait mode suitable for portrait shooting are provided. And Also,
The zoom ratio that can be designated is from 1 × (equal magnification) to 8 ×.

Next, the light distribution characteristics and irradiation angles of the strobe A18 and strobe B19 described above will be described. Figure 2 (a)
Is a diagram showing the light distribution characteristics and the irradiation angle of the strobe A18, and FIG. 6 (b) is a diagram showing the light distribution characteristics and the irradiation angle of the strobe B19. It is the figure which made the cross section in the direction.

In FIG. 1 (a), a strobe light A18 includes a light emitting portion 18a and a reflector (a cover,
This is shown by a reflector 18b. As shown in (a) of the figure, the light distribution angle of the strobe A 18 is set to the reflector 18b.
Due to the effect of the shape, the angle is about 60 °, and the illumination range is wider than that of the strobe B19. As a result, the strobe A18 has a light distribution characteristic mainly suitable for a wide-side zoom ratio, and a light distribution curve as shown in FIG. For example, on the plane A corresponding to the subject, the light amount at the point B, which is the center of the irradiation angle, is 100%.
Then, the points C which are about 60 ° apart from the center point B
And at point D, the amount of light is 50%.

In addition, in FIG.
Is the light emitting portion 19a and the reflector 1 arranged on the back surface thereof.
It is indicated by 9b. As shown in FIG. 2B, the light distribution angle of the strobe B19 is configured to be about 30 ° by the action of the shape of the reflector 19b.
It is configured so that the light can reach a distance farther than 8. As a result, the strobe B19 has a light distribution characteristic mainly suitable for the zoom ratio on the telephoto side, and a light distribution curve as shown in FIG. For example, in the plane E corresponding to the subject, if the light amount of the point F which is the center of the irradiation angle is 100%, the light amount is 50% at the points G and H which are separated from the center point F by about 30 °.

Next, the CPU 1 of the digital camera described above
The image capturing process will be described as an example of the control process performed by the first embodiment. The photographing process is realized by the CPU 11 reading and executing the camera program stored in the flash memory 14.

FIG. 3 is a flowchart showing an example of processing contents of the photographing processing. The photographing process is a process started when the photographer presses the release button and issues a photographing instruction. In the figure, first, in step S301, the focusing lens unit 3 is moved to the in-focus position by the AF processing described above, and the subject image formed on the image sensor 4 is photoelectrically converted by the AE processing described above. A photometric process is performed in which the brightness of the subject is measured based on the image data based on the output signal of the image sensor 4.

In step S302, the Bv value (subject brightness) is calculated from the brightness of the subject measured in the previous step by the above-described AE process. In S303, it is determined whether the strobe is used or not,
If the determination result is that the strobe is used, the process proceeds to S304, and if the strobe is not used, ISO10 is set.
The sensitivity corresponding to 0 is set, and the process proceeds to S306. still,
The use / non-use setting of the strobe is instructed by the photographer via a setting menu displayed by pressing the menu button, for example. In addition, in the present embodiment, the term “sensitivity” refers to a gain that is set to adjust the signal level of the image pickup signal that is the output signal of the image pickup device 4 (hereinafter the same).

In S304, which will be described in detail later with reference to FIG. 4, either strobe A18 or strobe B19 is selected according to the set shooting scene mode and zoom ratio. The set shooting scene mode is, for example, a mode instructed by the shooter by pressing a scene switching button. The set zoom ratio is specified by the photographer by pressing the zoom button, for example.

In step S305, the sensitivity is selected according to the set shooting scene mode, which will be described in detail later with reference to FIG. 5A. In S306, a process related to actual shooting is performed. That is, when the use of the strobe is selected, the strobe selected in S304 is emitted, and the subject image formed on the image sensor 4 at that time is photoelectrically converted into an electric signal. The signal level of a certain image pickup signal is adjusted according to the sensitivity selected in the above-described processing of S305, and A / A is added to the digital electric signal.
D converted.

Alternatively, when the unused state of the strobe is selected, the strobe does not emit light, and the subject image formed on the image pickup device 4 is photoelectrically converted into an electric signal, and the image pickup signal which is the electric signal is converted. The signal level is adjusted according to the sensitivity equivalent to ISO100, and A
/ D converted.

Then, with respect to the image data which is the digital electric signal thus obtained, the above-mentioned image processing section 7 is used.
The image processing by the, the compression processing by the compression / expansion unit 8, and the like are performed. In S307, the image data obtained in the previous step is recorded in the memory card 13, and this flow ends.

Next, a description will be given of the processing of S304 described above, in which either the strobe A18 or the strobe B19 is selected according to the set photographing scene mode and zoom ratio. FIG. 4 is a flowchart showing an example of the processing content of S304.

In the figure, first, in S401, it is determined whether or not the set strobe mode is the auto strobe mode. If the determination result is Yes, the process proceeds to S403, and if No. In the case of the manual strobe mode, the process proceeds to S402. still,
The set flash mode is, for example, a mode instructed by the photographer via the setting menu displayed by pressing the menu button.

In S402, the preset strobe is selected as the strobe to be used, and this flow returns. The preset flash is, for example, a flash designated by the photographer via a setting menu displayed by pressing a menu button.

Thus, for example, when the manual strobe mode is instructed by the photographer and a predetermined strobe is instructed, the instructed strobe is selected as the strobe to be used. In S403, it is determined whether or not the shooting scene mode is the auto mode. If the determination result is Yes, the reference zoom ratio is set to 4 times, and the process proceeds to S404. If No, the process proceeds to S407. Processing proceeds.

The reference zoom ratio is a zoom ratio that serves as a reference for selecting either the strobe A18 or the strobe B19 according to the set zoom ratio. In this embodiment, the strobe A18 is selected when the set zoom ratio is smaller than the reference zoom ratio, and the strobe B19 is selected when it is equal to or larger than the reference zoom ratio.

In S404, it is determined whether or not the zoom ratio (Z) is smaller than 4 times which is the reference zoom ratio (Z <4). If the determination result is Yes, the process proceeds to S405 and No In this case, the process proceeds to S406. S405
Then, the strobe A18 is selected, and this flow returns.

In step S406, the flash B19 is selected, and this flow returns. As a result, when the auto flash mode is set as the flash mode and the auto mode is set as the shooting scene mode, the reference zoom ratio is set to 4 times, and when the set zoom ratio is smaller than 4 times, In addition, the strobe A18 having a light distribution characteristic suitable for the wide side zoom ratio is selected, and when it is 4 times or more, the strobe B19 having a light distribution characteristic mainly suited for the tele side zoom ratio is selected. Become so.

In S407, it is determined whether or not the shooting scene mode is the high sensitivity mode, and the determination result is Yes.
In the case of, the reference zoom ratio is set to 6 times and the process proceeds to S408. In the case of No (in the case of portrait mode), the reference zoom ratio is set to 3 times and the process proceeds to S409.

In S408, it is determined whether or not the zoom ratio is smaller than 6 times which is the reference zoom ratio (Z <6). If the determination result is Yes, the process proceeds to S405 and N
If it is o, the process proceeds to S406. As a result, when the automatic strobe mode is set as the strobe mode and the high sensitivity mode is set as the shooting scene mode, the reference zoom ratio is set to 6 times, and when the set zoom ratio is smaller than 6 times, The strobe A18 having a light distribution characteristic mainly suited to the wide side zoom ratio is selected, and when it is 6 times or more, the strobe B19 having a light distribution characteristic mainly suited to the tele side zoom ratio is selected. Will be done. Therefore, even if the zoom ratio is instructed to the tele side (however, Z <6), the high sensitivity is set, and it is possible to reflect the photographing intention of the photographer of high sensitivity photographing.

In S409, the zoom ratio in the portrait mode is smaller than 3 times the reference zoom ratio (Z <3).
It is determined whether or not, and if the determination result is Yes, S
The process proceeds to step 405, and if No, the process proceeds to step S406. As a result, when the auto strobe mode is set as the strobe mode and the portrait mode is set as the shooting scene mode, the reference zoom ratio is set to 3 times, and when the set zoom ratio is smaller than 3 times, The strobe A18 having a light distribution characteristic mainly suited to the wide side zoom ratio is selected, and when it is 3 times or more, the strobe B19 having a light distribution characteristic mainly suited to the tele side zoom ratio is selected. Will be done. Therefore, even if the zoom ratio is instructed to the wide side (however, Z ≧ 3), S
The low sensitivity with less deterioration of the / N ratio is set, and it becomes possible to reflect the photographing intention of the photographer called portrait photography.

In this flow, an example in which the reference zoom ratio is automatically set according to the set shooting mode is shown. However, for example, shooting is performed via the setting menu displayed by pressing the menu button. It is also possible for the person to instruct. In this case, the designated reference zoom ratio is preferentially set regardless of the set shooting mode.

Next, the process of setting the sensitivity according to the set shooting scene mode, which is the process of S305, will be described. FIG. 5A is a flowchart showing an example of the processing contents of S305, and FIG.
FIG. 6 is a diagram showing the relationship between the shooting scene mode and the sensitivity range determined by the processing of FIG.

In FIG. 5A, first, in S501,
It is determined whether or not the upper limit of sensitivity is set. If the determination result is Yes, the process proceeds to S502, No.
In the case of, the processing proceeds to S504. The upper limit of the sensitivity that is set is instructed by the photographer via the setting menu displayed by pressing the menu button, for example.

In S502, the upper limit of the sensitivity that has been set is set as the upper limit sensitivity, and the process proceeds to S503.
Thus, for example, when the upper limit of the sensitivity is instructed by the photographer, the upper limit of the instructed sensitivity is preferentially set as the upper limit sensitivity regardless of the set shooting mode.

In step S503, the sensitivity corresponding to the Bv value calculated in the process of step S302 is selected within the set upper limit sensitivity, and this flow returns. S5
In 04, it is determined whether or not the set shooting mode is the auto mode. If the determination result is Yes, the process proceeds to S505, and if No, the process proceeds to S506.

In S505, the sensitivity equivalent to ISO400 is set as the upper limit sensitivity, and the process proceeds to S503.
As a result, when the auto mode is set,
Within the range where the sensitivity equivalent to ISO400 is the upper limit sensitivity, B
The sensitivity is set according to the v value.

In S506, it is determined whether or not the set photographing mode is the high sensitivity mode. If the determination result is Yes, the process proceeds to S507, and if No (in the portrait mode). Advances to S508. In S507, the sensitivity equivalent to ISO800 is set as the upper limit sensitivity, and the process proceeds to S503.

As a result, when the high sensitivity mode is set, the sensitivity corresponding to the Bv value is set within the range in which the sensitivity corresponding to ISO800, which is high sensitivity, is the upper limit sensitivity. In S508, the sensitivity equivalent to ISO200 is set as the upper limit sensitivity, and the process proceeds to S503.

As a result, when the portrait mode is set, within the range where the sensitivity equivalent to ISO200, which is low sensitivity with little deterioration of the S / N ratio, is the upper limit sensitivity,
The sensitivity is set according to the Bv value. That is, when the portrait mode is set, the upper limit of sensitivity is set lower than when the other shooting modes are selected.

As a result of the above processing, as shown in FIG. 6B, when the upper limit of sensitivity is not set in advance and the auto mode is set as the shooting scene mode, the upper limit sensitivity equivalent to ISO400 is set. ISO5
Within the range of 0 to ISO400 (however, ISO50,
100, 200, or 400), the sensitivity is set according to the Bv value. In that case, when the portrait mode is set as the shooting scene mode, the upper limit sensitivity equivalent to ISO200 is set, and
Within the range of SO50 to ISO200 (however, ISO
Any of 50, 100, and 200), the sensitivity according to the Bv value is set. Further, in this case, when the high sensitivity mode is set as the shooting scene mode, the upper limit sensitivity equivalent to ISO800 is set, and the ISO5
Within the range of 0 to ISO800 (however, ISO50,
Any of 100, 200, 400, and 800), the sensitivity according to the Bv value is set.

As described above, FIG. 3, FIG. 4, and FIG.
By executing the shooting process in (b), the flash to be used is selected according to the set shooting mode and zoom ratio, and according to the set shooting mode.
The gain is set according to the brightness of the subject, and shooting is performed. As a result, it is possible to select an appropriate strobe and appropriately increase the gain according to the shooting intention of the photographer.

Next, a concrete example of the strobe and the sensitivity selected when the photographing process shown in FIG. 3, FIG. 4 and FIG. ), (c), (d), (e)
It demonstrates using. 6 (a) to 6 (e) are diagrams illustrating a specific example when the above-described shooting process is executed, which corresponds to the shooting mode and is selected according to the set zoom ratio and subject distance. 2 shows an example of the sensitivity that is set with the flash.

However, FIGS. 7A, 7C and 7E are diagrams relating to the above-mentioned photographing processing, and FIGS. 7B and 7D are diagrams relating to the conventional photographing processing. In addition, it is assumed that the instruction of the manual strobe mode and the instruction of the upper limit sensitivity are not given in (a), (c), and (e) of FIG. In addition, in (a) to (e) of FIG.
The vertical axis represents the subject distance L, and the horizontal axis represents the zoom ratio.
Further, on the horizontal axis, W represents the wide side, T represents the tele side, N0, N1, N2 represent the reference zoom ratios, x1, x3,
× 4, × 6, and × 8 represent zoom ratios of 1 ×, 3 ×, 4 ×, 6 ×, and 8 ×. Also, 50, 100, 200, 4
00 and 800 represent ISO equivalent sensitivity.

FIG. 11A is a diagram showing a specific example of the strobe and sensitivity selected when the auto mode is set as the photographing mode. In the example shown in FIG.
The standard zoom ratio is 4 depending on the set auto mode.
It is set to double (N0 position) and the upper limit sensitivity is ISO
The sensitivity is set to 400.

The four curves corresponding to ISO 50 to 400 in FIG. 10A are the curves showing the maximum object distance photographed with proper brightness at each sensitivity. If the area is below this curve, it indicates that the image is captured properly at that sensitivity. As shown in (a) of the figure, the maximum subject brightness becomes longer as the sensitivity becomes higher. The maximum subject brightness becomes shorter as the zoom ratio becomes larger. This is because as the zoom ratio becomes larger, the shooting angle of view becomes narrower, and a part of the range illuminated by the strobe is shot. Further, these curves also differ depending on the selected strobe A18 or strobe B19. This is because, as described above, the strobe B19 has a narrower light distribution angle, and therefore the reaching distance is longer even with the same zoom ratio.

For example, it is assumed that the set zoom ratio and subject distance are the values of point a in FIG. In this case, since the zoom ratio of the point a is smaller than the reference zoom ratio, the strobe A18 is selected. Regarding the sensitivity, since the object distance of point a is above the curve of sensitivity corresponding to ISO200 and below the curve of sensitivity corresponding to ISO400 in FIG. 7A, the sensitivity corresponding to ISO400 is selected.

Further, FIGS. 11B and 11C are diagrams showing specific examples of the strobe and the sensitivity selected when the portrait mode is set as the photographing mode. However, the same figure (b) is a diagram showing a specific example of conventional imaging processing,
(c) is a diagram showing a specific example relating to the above-described photographing processing.
In addition, in FIGS. 6B and 6C, the subject and the subject distance at points B and C are the same. Further, the curves for each sensitivity corresponding to ISO50 to ISO200 are as described above (the same in FIG. 7C).

In the example shown in FIG. 9B relating to the conventional photographing process, the reference zoom ratio is uniformly set to the intermediate zoom ratio (in this case, 4 times) regardless of the set photographing mode. In this example, the selected strobe and the point b indicating the sensitivity are determined on the basis of the brightness of the subject at a predetermined distance and the set zoom ratio. That is, in this case, since the set zoom ratio becomes smaller than the reference zoom ratio, the strobe A18 is selected, and the sensitivity equivalent to ISO200 is selected based on the brightness of the subject. Since the upper limit sensitivity is not set in the conventional image capturing process, a sensitivity equal to or higher than ISO400 may be set depending on the image capturing condition, which is a mode such as the portrait mode that prioritizes image quality. Nevertheless, the high sensitivity is set and the S / N ratio deteriorates, which may make it impossible to reflect the photographing intention of the photographer.

On the other hand, FIG. 6 relating to the above-described photographing processing of FIG.
In the example shown in (c), the reference zoom ratio is set to 3 times (the position of N1) according to the set portrait mode, the upper limit sensitivity is set to the sensitivity equivalent to ISO200, and the predetermined distance away. This is an example in which the point c indicating the selected strobe and sensitivity (in this case, the same position as point b in FIG. 6B) is determined based on the brightness of the subject and the set zoom ratio. That is, in this case, since the set zoom ratio becomes larger than the reference zoom ratio, the strobe B19 is selected, and the sensitivity equivalent to ISO100 is selected based on the brightness of the subject. As described above, according to the above-described shooting process, unlike the case of the conventional shooting process, the strobe B19 suitable for the zoom ratio on the telephoto side is used to illuminate the strobe light to a long distance to make the subject bright and low. It becomes possible to select the sensitivity. Therefore, it becomes possible to select an appropriate low sensitivity in the portrait mode that prioritizes image quality, and it is possible to reflect the photographing intention of the photographer.

Further, FIGS. 9D and 9E are diagrams showing specific examples of strobes and sensitivities selected when the high sensitivity mode is set as the photographing mode. However, the same figure (d)
FIG. 4 is a diagram showing a specific example of a conventional image capturing process, and FIG. 6E is a diagram showing a specific example of the above-described image capturing process. Also,
In (d) and (e) of the same figure, the subject and the subject distance at point D and point E are the same. Further, the curves for each sensitivity corresponding to ISO50 to ISO800 are as described above (the same in FIG. 8E).

In the example shown in FIG. 3D relating to the conventional photographing process, the reference zoom ratio is uniformly set to the intermediate zoom ratio (in this case, 4 times) regardless of the photographing mode, and the predetermined zoom ratio is set. This is an example in which the point D indicating the selected strobe and the sensitivity is determined based on the brightness of the distant subject and the set zoom ratio. That is, in this case, since the set zoom ratio is larger than the reference zoom ratio, the strobe B19 is selected, and the sensitivity corresponding to ISO400 is selected based on the brightness of the subject.

On the other hand, FIG. 6 relating to the above-mentioned photographing processing of FIG.
In the example shown in (e), the reference zoom ratio is set to 6 times (N2 position) according to the set high sensitivity mode, the upper limit sensitivity is set to the sensitivity equivalent to ISO800, and the predetermined distance This is an example in which the point e indicating the selected strobe and sensitivity (in this case, the same position as point D in FIG. 7D) is determined based on the brightness of the subject and the set zoom ratio. That is, in this case, since the set zoom ratio is smaller than the reference zoom ratio, the strobe A18 is selected, and the ISO 80 is selected based on the brightness of the subject.
A sensitivity equivalent to 0 is selected. As described above, according to the above-described shooting process, unlike the case of the conventional shooting process, it is possible to perform shooting with a wide illumination range using the strobe light A18 suitable for the wide-side zoom ratio. . Therefore, it is possible to select a high sensitivity suitable for high-sensitivity shooting, which is a high-sensitivity mode, and it is possible to reflect the shooting intention of the photographer.

In the present embodiment, an example is shown in which the photographing process shown in FIGS. 3, 4 and 5 (a) is executed in the digital camera having the two strobes shown in FIG. For example, in the case of a digital camera equipped with one strobe, the process of S304 may be skipped in the shooting process, and the one strobe provided may be executed as the strobe to be used. In the case of a digital camera not equipped with a strobe, the process of S304 may be skipped in the shooting process and the process may be executed. This allows
Even in a digital camera with one strobe or a digital camera without a strobe, the upper limit sensitivity is set according to the set shooting mode, and the sensitivity according to the subject brightness is set within that range. Therefore, it becomes possible to set the optimum sensitivity for reflecting the photographer's intention of photographing.

Further, in the present embodiment, the gain is increased by adjusting the signal level of the analog electric signal which is the output signal from the image pickup device 4. However, for example, the output signal from the image pickup device 4 is changed. A predetermined image processing may be performed on the image data which is a digital electric signal based on the image data, so that the same effect as gain increase may be obtained.

Although the digital camera of the present invention has been described above in detail, the present invention is not limited to the above embodiment,
It goes without saying that various improvements and changes may be made without departing from the scope of the present invention.

[0078]

As described above in detail, according to the present invention, the gain can be appropriately increased according to the photographer's intention of photographing, and the two kinds of strobes having different light distribution characteristics are provided. In addition, in the digital camera, an appropriate strobe can be selected according to the photographer's intention of photographing, and appropriate gain up can be performed.

[Brief description of drawings]

FIG. 1 is a configuration example of a digital camera according to an embodiment of the present invention.

FIG. 2A is a diagram showing a light distribution characteristic of a strobe A and an irradiation angle, and FIG. 2B is a diagram showing a light distribution characteristic of a strobe B and an irradiation angle.

FIG. 3 is a flowchart illustrating an example of processing contents of a shooting process.

FIG. 4 is a flowchart showing an example of processing contents of processing of S304.

5A is a flowchart showing an example of processing contents of processing of S305, and FIG. 5B is a diagram showing a relationship between a shooting scene mode determined by the processing of FIG.

6 (a), (b), (c), (d), and (e) are diagrams illustrating a specific example when a shooting process is executed.

[Explanation of symbols]

1 Shooting lens section 2 Lens part for zoom 3 Focus lens section 4 image sensor 5 Imagination Department 6 DRAM 7 Image processing section 8 compression / expansion section 9 LCD display 10 AF / AE section 11 CPU 12 buses 13 memory card 14 Flash memory 15, 16 Drive motor / circuit part 17 Strobe control / switching circuit 18 Strobe A 18a light emitting unit 18b reflector 19 Strobe B 19a light emitting part 19b reflector 20 Operation means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // H04N 101: 00 H04N 101: 00 F term (reference) 2H002 AB04 2H053 AB03 BA34 5C022 AA13 AB15 AB20 AB66

Claims (8)

[Claims] 1. A photographing mode selecting means for selecting a photographing mode, and an upper limit of the gain is set according to the photographing mode selected by the photographing mode selecting means, and an object brightness is set within a range not more than the upper limit of the gain. A digital camera, comprising: a gain setting unit that sets a gain, and a signal level adjusting unit that adjusts a signal level of an image pickup signal based on the gain set by the gain setting unit. 2. The gain setting means sets the upper limit of the gain to be lower when a shooting mode that prioritizes image quality is selected by the shooting mode selection means than when another mode is selected. The digital camera according to claim 1, wherein the digital camera is a digital camera. 3. An upper limit instructing unit for instructing an upper limit of the gain is further provided, and the gain setting unit is selected by the photographing mode selecting unit when the upper limit of the gain is instructed. The digital camera according to claim 1 or 2, wherein an upper limit of the gain instructed by the upper limit instructing unit is set regardless of a photographing mode. 4. A zoom ratio indicating means for instructing a zoom ratio of a zoom photographing optical system, a photographing mode selecting means for selecting a photographing mode, a first flashing means, and a light distribution narrower than the first flashing means. A second flash unit having a characteristic, the first flash unit or the second flash unit according to a zoom ratio designated by the zoom ratio designating unit and a photographing mode selected by the photographing mode selecting unit. A digital camera comprising: a selection unit that selects any one of the units. 5. The selecting means sets a reference zoom ratio as a reference according to the photographing mode selected by the photographing mode selecting means, and the set reference zoom ratio and the zoom ratio instructing means indicate the reference zoom ratio. The digital camera according to claim 4, wherein one of the first flash unit and the second flash unit is selected by comparing zoom ratios. 6. A gain setting means for setting an upper limit of gain according to the photographing mode selected by the photographing mode selecting means, and setting a gain according to subject brightness within a range not more than the upper limit of gain. 6. The digital camera according to claim 4, further comprising signal level adjusting means for adjusting the signal level of the image pickup signal based on the gain set by the gain setting means. 7. A zoom ratio designating means for designating a zoom ratio of a zoom photographing optical system, a first flashing means, and a second flashing means having a light distribution characteristic narrower than that of the first flashing means. The flash means to be selected is either an automatic strobe mode automatically selected according to the zoom ratio designated by the zoom ratio designating means or a manual strobe mode selected according to the instruction regardless of the zoom ratio. A digital camera comprising: a mode selection unit for selecting whether or not. 8. A zoom ratio instructing means for instructing a zoom ratio of a zoom photographing optical system, a first flashing means, a second flashing means having a light distribution characteristic narrower than that of the first flashing means, A selection unit for selecting either the first flash unit or the second flash unit according to the zoom ratio designated by the zoom ratio designation unit, and a reference zoom serving as a reference for switching the selection by the selection unit. A digital camera comprising: an indicating means for indicating a ratio.