JP4169524B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera, and more particularly to camera exposure control.
[0002]
[Prior art]
Conventionally, with regard to camera exposure control, daytime synchro photography is automatically performed in order to prevent the main subject from being underexposed during backlighting.
[0003]
At this time, a method disclosed in Japanese Patent No. 293472 is known as a backlight determination method for determining whether to perform daytime synchro shooting automatically.
[0004]
That is, according to this backlight determination method, backlight determination based on the output of the photometric sensor that measures the luminance of the central region and the peripheral region of the shooting screen and backlight determination based on the output of the image sensor for performing focus detection are performed. .
[0005]
Then, when it is determined that the backlight is the backlight in one of the two backlight determinations, it is determined that the backlight shooting is performed, and the daytime synchro shooting is performed.
[0006]
[Problems to be solved by the invention]
In the backlight determination method disclosed in the above-mentioned Japanese Patent No. 293472, there is a description that the backlight determination using the photometric sensor and the backlight determination using the image sensor are performed independently.
[0007]
However, this Japanese Patent No. 293472 describes backlight determination using a combination of two sensors, a photometric sensor and an image sensor, and how to use the two sensors, the photometric sensor and the image sensor, according to the subject brightness. There is no.
[0008]
Also, in general, with conventional camera exposure control, if the background is high brightness when shooting in a snowy mountain or the like, it is very difficult to determine backlighting by a photometric sensor due to the effects of stray light or crosstalk. Have a problem.
[0009]
The present invention has been made in view of the above-described circumstances, and provides a camera that can solve a problem of high-intensity backlight shooting, which is a scene in which photometry is difficult, and can take beautiful pictures. The purpose is to do.
[0010]
[Means for Solving the Problems]
According to the present invention, in order to solve the above problems,
(1) a photometric means for measuring the average subject brightness in the shooting screen and the subject brightness at the center;
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The exposure control means, when the brightness determination means determines that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness, the distance measurement means Perform exposure control by obtaining the brightness based on the image data of the distance measurement area where the detected main subject exists,
If the luminance determination unit determines that the average luminance of the subject in the shooting screen measured by the photometry unit is lower than the predetermined luminance, the luminance determination unit uses the photometry unit. Comparing the average subject brightness and the central subject brightness to determine the brightness difference between the average subject brightness and the central subject brightness,
In the exposure control means, the brightness of the subject in the center is determined by the brightness determination means. Average subject brightness With less brightness And the difference between the average subject brightness and the center subject brightness is larger than a predetermined brightness difference. When it is determined, exposure control is performed based on the subject brightness in the center, Whether the subject brightness in the central portion is lower than the average subject brightness and the difference between the average subject brightness and the subject brightness in the central portion is smaller than a predetermined brightness difference Or the subject brightness at the center Than the average subject brightness When it is determined that the brightness is high, a camera is provided that performs exposure control based on the average subject brightness.
[0011]
Further, according to the present invention, in order to solve the above problems,
(2) photometric means for measuring an average subject brightness in the shooting screen and a subject brightness at the center;
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The brightness determining means, when the brightness determining means determines that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness, the distance measuring means Determine the brightness of the main subject based on the image data of the detected ranging area where the main subject exists,
The exposure control means, when the brightness determination means determines that the difference between the average subject brightness measured by the photometry means and the brightness of the main subject measured by the distance measurement means is smaller than a predetermined value, When the average brightness of the subject by the metering means is determined to be large, exposure control is performed by the brightness of the main subject by the distance measuring means,
If the luminance determination unit determines that the average luminance of the subject in the shooting screen measured by the photometry unit is lower than the predetermined luminance, the luminance determination unit uses the photometry unit. Comparing the average subject brightness and the central subject brightness to determine the brightness difference between the average subject brightness and the central subject brightness,
In the exposure control means, the brightness of the subject in the center is determined by the brightness determination means. Average subject brightness With less brightness And the difference between the average subject brightness and the center subject brightness is larger than a predetermined brightness difference. When it is determined, exposure control is performed based on the subject brightness in the center, Whether the subject brightness in the central portion is lower than the average subject brightness and the difference between the average subject brightness and the subject brightness in the central portion is smaller than a predetermined brightness difference Or the subject brightness at the center Than the average subject brightness When it is determined that the brightness is high, a camera is provided that performs exposure control based on the average subject brightness.
[0012]
Further, according to the present invention, in order to solve the above problems,
(3) a photometric means for measuring an average subject brightness in the shooting screen and a subject brightness at the center;
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Electronic flash means for illuminating the subject during shooting,
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The brightness determining means detects by the distance measuring means when it is determined by the brightness determining means that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness. The luminance of the main subject is determined based on the image data of the distance measurement area where the main subject exists,
The exposure control means is configured such that the brightness of the main subject measured by the distance measuring means is higher than the average subject brightness measured by the photometry means or higher than the average subject brightness measured by the brightness determination means. Exposure control is performed based on the average subject brightness by the photometry means when it is determined that the difference between the brightness of the main subject and the main subject is smaller than a predetermined value. Control exposure,
The luminance determination means determines an average subject luminance in the shooting screen by the luminance determination means. Above When it is determined that the luminance is lower than a predetermined luminance, the average subject luminance obtained by the photometry means and the central subject luminance are compared, and the average subject luminance and the central subject luminance are determined. Find the difference
In the exposure control means, the brightness of the subject in the center is determined by the brightness determination means. Average subject brightness Lower brightness than And the difference between the average subject brightness and the center subject brightness is larger than a predetermined brightness difference. When it is determined, exposure control is performed based on the subject brightness in the center, Whether the subject brightness in the central portion is lower than the average subject brightness and the difference between the average subject brightness and the subject brightness in the central portion is smaller than a predetermined brightness difference Or the subject brightness at the center Than the average subject brightness When it is determined that the brightness is high, a camera is provided that performs exposure control based on the average subject brightness.
[0013]
Further, according to the present invention, in order to solve the above problems,
(4) a photometric means for measuring an average subject brightness in the shooting screen and a subject brightness at the center;
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Electronic flash means for illuminating the subject during shooting,
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
Back light determination means for performing back light determination of a photographic scene based on a determination result by the brightness determination means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The backlight determining unit determines that the distance determining unit determines that the average determining unit within the shooting screen measured by the photometric unit has a luminance higher than a predetermined luminance by the luminance determining unit. Based on the image data of each distance measurement area, make a backlight determination,
The exposure control unit performs exposure control based on an average photometric value obtained by the photometry unit when the backlight determination unit determines that the backlight is not backlit, and causes the electronic flash unit to emit light when it is determined that the backlight is backlit. Done
The brightness determination means determines the average by the photometry means when the brightness determination means determines that the average subject brightness in the shooting screen measured by the photometry means is lower than the predetermined brightness. Comparing the average subject brightness and the central subject brightness to obtain a brightness difference between the average subject brightness and the central subject brightness,
In the exposure control means, the brightness of the subject in the center is determined by the brightness determination means. Average subject brightness With less brightness And the difference between the average subject brightness and the center subject brightness is larger than a predetermined brightness difference. When it is determined, exposure control is performed based on the subject brightness in the center, Whether the subject brightness in the central portion is lower than the average subject brightness and the difference between the average subject brightness and the subject brightness in the central portion is smaller than a predetermined brightness difference Or the subject brightness at the center Than the average subject brightness When it is determined that the brightness is high, a camera is provided that performs exposure control based on the average subject brightness.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
(First embodiment)
FIG. 1 is a block diagram showing the configuration of the main part of the camera of the present invention. In FIG. 1, reference numeral 101 is photometric means for measuring subject luminance information in the shooting screen, and reference numeral 102 is This is a distance measuring means for measuring subject distance information in the photographing screen.
[0016]
Reference numeral 103 is lens driving means for driving a focus adjustment lens based on distance measurement information from the distance measuring means 102, and reference numeral 104 is shutter means for exposing the film.
[0017]
Reference numeral 105 is a film feeding means for winding and rewinding the film, and reference numeral 106 is an electronic flash for illuminating the subject by emitting light at the time of low brightness or backlight as described later. A strobe as a means.
[0018]
Reference numeral 107 denotes a focal length detection unit that detects focal length information of the photographing lens, and reference numeral 108 denotes a nonvolatile memory such as an EEPROM that stores various setting values, adjustment values, and the like.
[0019]
Reference numeral 109 is a CPU that controls and calculates the sequence of the entire camera, and reference numeral 110 is used to instruct the camera to perform measurement and calculation of subject information necessary for shooting such as distance measurement and photometry. The first release switch (1RSW).
[0020]
Reference numeral 111 denotes a second release switch (2RSW) for instructing the camera to perform shooting based on subject information measured and calculated by turning on the 1RSW 110.
[0021]
Reference numeral 112 is luminance determination means for determining whether or not the shooting scene has high luminance based on the average luminance in the shooting screen measured by the photometry means 101.
[0022]
Reference numeral 113 controls the shutter unit 104 and the strobe 106 based on luminance information selected by the luminance determining unit 112 and a backlight determining unit 114 described later and information on necessity of light emission of the strobe 106. Exposure control means for performing exposure.
[0023]
Reference numeral 114 denotes a backlight determination unit that performs backlight determination based on luminance information in the photographing screen measured by the photometry unit 101 and the distance measurement unit 102.
[0024]
FIG. 2 is a block diagram showing an internal configuration of the photometric means 101 in the camera of the present invention. In FIG. 2, reference numeral 121 denotes an average photometric sensor 122 and a spot photometric sensor 125, which will be described later, with respect to light components in the photographing screen. This is a photometric lens for guiding
[0025]
Reference numeral 122 is an average photometric sensor that measures the average luminance in the photographing screen guided by the photometric lens 121, and reference numeral 123 is a control of the integration operation of the average photometric sensor 122 and the spot photometric sensor 125. This is an integral control means for photometry.
[0026]
Reference numeral 124 denotes A / D conversion means for analog / digital (A / D) conversion of the integrated outputs of the average photometric sensor 122 and the spot photometric sensor 125, and the reference numeral 125 is guided by the photometric lens 121. This is a spot photometric sensor that measures the luminance at the center of the photographed screen.
[0027]
FIG. 3 is a block diagram showing an internal configuration of the distance measuring means 102 in the camera of the present invention. In FIG. 3, reference numerals 131a and 131b form subject images on line sensors 132a and 132b described later. It is a light receiving lens for
[0028]
Reference numerals 132a and 132b are line sensors that photoelectrically convert a subject image formed by the light receiving lenses 131a and 131b according to the light intensity and output an electrical signal.
[0029]
Reference numeral 133 is a distance measurement integration control means for controlling the integration operation of the line sensors 132a and 132b. Reference numeral 134 reads out the subject image signal from the line sensors 132a and 132b and performs A / D conversion. Is a reading means.
[0030]
FIG. 4 is a flowchart for explaining the procedure of the release sequence of the camera according to the first embodiment configured as described above.
[0031]
That is, as shown in FIG. 4, first, in step S101, when a power switch of a camera (not shown) is turned on, various setting values, adjustment values, and other data are read from the nonvolatile memory 108 such as an EEPROM. A process of expanding in the RAM of the CPU 109 is performed.
[0032]
Next, in step S102, a process for determining whether or not a power switch of a camera (not shown) is off is performed. If it is off, the release sequence is terminated, and if it is on, the process of step S103 is performed. Proceed to processing.
[0033]
Next, in step S103, it is determined whether or not 1RSW 110 is on. If it is on, the process proceeds to step S104. If it is off, the process returns to step S102.
[0034]
Next, in step S104, photometry processing is performed, and the average luminance in the photographing screen and the luminance at the center are measured.
[0035]
Next, in step S105, distance measurement processing is performed, and based on distance measurement data of each of a plurality of distance measurement areas in the shooting screen, a main subject is detected by a method such as closest detection to obtain subject distance data. Processing is performed.
[0036]
Next, in step S106, it is determined whether or not the average luminance in the shooting screen obtained in the photometric process in step S104 is higher than a predetermined luminance. If the average luminance is higher than the predetermined luminance, step S117 is performed. The process proceeds to a process for calculating the main subject brightness as exposure calculation data. If the brightness is low, the process proceeds to step S107.
[0037]
Next, in step S107, the average luminance in the photographing screen obtained by the photometric processing in step S104 is compared with the luminance in the central portion to obtain a luminance difference between the average luminance in the photographing screen and the luminance in the central portion, A determination process is performed to determine whether or not the brightness at the center is lower than the predetermined brightness difference. If the brightness is low, the process proceeds to step S108. If the brightness is high, the process proceeds to a process of selecting the average brightness in the shooting screen as exposure calculation data in step S116.
[0038]
Next, in step S108, a process of selecting the luminance at the center in the photographing screen obtained in the photometric process in step S104 as exposure calculation data described later is performed.
[0039]
Next, in step S109, a process for calculating exposure control data is performed by performing an exposure calculation based on the luminance information selected or calculated in any of steps S108, S116, and S117.
[0040]
Next, in step S110, a process of calculating the extension amount of a focus adjusting lens (not shown) based on the subject distance data obtained in step S105 is performed.
[0041]
Next, in step S111, it is determined whether or not the 1RSW 110 is on. If it is on, the process proceeds to step S112. If it is off, the process returns to step S102.
[0042]
Next, in step S112, a process for determining whether or not the 2RSW 111 is on is performed. If it is on, the process proceeds to step S113, and if it is off, the process returns to step S111.
[0043]
Next, in step S113, the lens driving unit 103 performs a process of extending a focus adjustment lens (not shown) according to the extension amount obtained in step S110.
[0044]
Next, in step S114, the shutter unit 104 performs an exposure process according to the exposure control data obtained in step S109.
[0045]
Next, in step S115, after the film feeding means 105 performs a film one-frame winding process, the process returns to step S102.
[0046]
In step S116, a process of selecting the average luminance in the photographing screen obtained by the photometric process in step S104 as the exposure calculation data in step S109 is performed.
[0047]
In step S117, the luminance of the main subject detected by the distance measuring process in step S105 is calculated, and the process for selecting as the exposure calculation data in step S109 is performed.
[0048]
(Summary of First Embodiment)
As described above, in the camera according to the first embodiment, first, photometry is performed by the photometric means 101, and the average luminance BV (A) of the entire shooting screen and the luminance BV (C) of the central portion of the shooting screen. Then, the distance measuring means 102 measures a plurality of areas including the central area in the shooting screen, detects the main subject by a method such as the closest selection, and obtains the subject distance data.
[0049]
Next, the exposure controller 113 determines that the average luminance BV (A) in the shooting screen is higher than the predetermined luminance BV (TH) by the luminance determination unit 112 (for example, BV10 or more). The luminance BV (M) of the main subject detected by the distance measuring means 102 is used, for example, as the following (1) using the integration amount V and the integration time T of the main subject portion of the subject image data acquired at the time of distance measurement. The exposure control is performed based on the main subject brightness BV (M).
[0050]
BV (M) = log V−log T + log K) (1)
Here, K is a useless coefficient for correcting the variation of each sensor.
[0051]
Further, when the average luminance BV (A) is lower than the predetermined luminance BV (TH) (for example, BV10 or less), the luminance determination unit 112 determines the average luminance of the entire photographing screen obtained by the photometric unit 101. The difference between the overall average brightness BV (A) and the central brightness BV (C) is obtained by comparing BV (A) with the brightness BV (C) at the center in the shooting screen.
[0052]
Then, when the brightness determination unit 112 determines that the brightness BV (A) at the center is lower than a predetermined brightness difference (for example, 1 BV), the exposure control unit 113 determines the brightness BV (A) at the center. The exposure control is performed based on the brightness difference, and when it is determined that the brightness difference is within the predetermined brightness difference or the brightness BV (C) at the center is higher, the exposure control is performed based on the average brightness BV (A). .
[0053]
By performing exposure control as described above, exposure control is performed based on the brightness of the background when shooting a person, etc. under high brightness such as in snowy mountains or summer beaches. Can be prevented.
[0054]
According to the camera of the first embodiment, it is possible to perform photographing with appropriate exposure of the main subject in photographing under high luminance.
[0055]
(Second Embodiment)
The camera according to the second embodiment has the same configuration as the camera according to the first embodiment described above.
[0056]
FIG. 5 is a flowchart for explaining the procedure of the release sequence of the camera according to the second embodiment configured in the same manner as the camera according to the first embodiment described above.
[0057]
That is, as shown in FIG. 5, first, in step S201, when a power switch of a camera (not shown) is turned on, data such as various setting values and adjustment values are read from the nonvolatile memory 108 such as an EEPROM. A process of expanding in the RAM of the CPU 109 is performed.
[0058]
Next, in step S202, a process for determining whether or not a power switch of a camera (not shown) is off is performed. If it is off, the release sequence is terminated, and if it is on, the process proceeds to step S203. Proceed to processing.
[0059]
Next, in step S203, a determination process is performed to determine whether 1RSW 110 is on. If it is on, the process proceeds to step S204, and if it is off, the process returns to step S202.
[0060]
Next, in step S204, photometric processing is performed, and the average luminance in the photographing screen and the luminance at the center are measured.
[0061]
Next, in step S205, distance measurement processing is performed, and based on the distance measurement data of each of the plurality of distance measurement areas in the shooting screen, the main subject is detected by a method such as closest detection to obtain subject distance data. Processing is performed.
[0062]
Next, in step S206, a determination process is performed to determine whether or not the average luminance in the shooting screen obtained by the photometric process in step S204 is higher than a predetermined luminance.
[0063]
If the luminance is high, the process proceeds to the process of calculating the main subject luminance in step S207. If the luminance is low, the process proceeds to step S217.
[0064]
Next, in step S207, a process of calculating the main subject brightness detected in the distance measuring process in step S205 is performed.
[0065]
Next, in step S208, the average brightness in the shooting screen is compared with the average brightness in the shooting screen obtained in the photometric process in step S204 and the main subject brightness calculated in step S207. The luminance difference is obtained.
[0066]
If the luminance difference is larger than the predetermined value, the process proceeds to step S209. If the difference is smaller, the process proceeds to step S218.
[0067]
Next, in step S209, processing for selecting the main subject brightness calculated in step S207 as exposure calculation data is performed.
[0068]
Next, in step S210, a process for calculating exposure control data is performed by performing exposure calculation based on the luminance information selected in any of step S209 and steps S218 and S219 described later.
[0069]
Next, in step S211, a process of calculating the extension amount of a focus adjustment lens (not shown) based on the subject distance data obtained in step S205 is performed.
[0070]
Next, in step S212, it is determined whether or not the 1RSW 110 is on. If it is on, the process proceeds to step S213, and if it is off, the process returns to step S202.
[0071]
Next, in step S213, it is determined whether or not the 2RSW 111 is on. If it is on, the process proceeds to step S214. If it is off, the process returns to step S212.
[0072]
Next, in step S214, the lens driving unit 103 performs a process of extending a focus adjustment lens (not shown) according to the extension amount obtained in step S211.
[0073]
Next, in step S215, exposure processing is performed by the shutter unit 104 in accordance with the exposure control data obtained in step S210.
[0074]
Next, in step S216, the film feeding unit 105 performs a film one-frame winding process, and then returns to the process in step S202.
[0075]
Next, in step S217, a difference in brightness between the average brightness in the shooting screen and the brightness in the center is obtained by comparing the average brightness in the shooting screen obtained by the photometric processing in step S204 with the brightness in the center. .
[0076]
Here, it is determined whether or not the luminance at the center is lower than the predetermined luminance difference. If the luminance is low, the process proceeds to step S219, and if the luminance is within the predetermined luminance difference. If so, the process proceeds to step S218.
[0077]
Next, in step S218, a process for selecting the average luminance in the photographing screen obtained by the photometric process in step S204 as exposure calculation data is performed.
[0078]
Next, in step S219, a process for selecting the brightness at the center in the photographing screen obtained by the photometric process in step S204 as exposure calculation data is performed.
[0079]
(Summary of Second Embodiment)
As described above, the camera according to the second embodiment is a camera having the same configuration as that of the camera according to the first embodiment described above. The BV (A) and the luminance BV (C) at the center of the shooting screen are obtained, the distance measuring means 102 measures a plurality of areas including the center area in the shooting screen, and the main subject is selected by a method such as closest selection. To detect subject distance data.
[0080]
Next, the luminance determining unit 112 determines that the average luminance BV (A) in the shooting screen is higher than the predetermined luminance BV (TH) (for example, V10 or more), the distance measuring unit 102. The brightness BV (M) of the main subject detected in step 1 is obtained by the same method as in the first embodiment, and the average brightness BV (A) and the brightness BV (M) of the main subject are compared to compare the overall average brightness BV ( The difference between A) and the luminance BV (C) at the center is obtained.
[0081]
The exposure control means 113 is determined to be small on the basis of the main subject brightness BV (M) when the brightness determination means 112 determines that the brightness difference is larger than a predetermined value (for example, 1 BV). Sometimes exposure control is performed based on the average luminance BV (A).
[0082]
In addition, when it is determined that the average luminance BV (A) is lower than the predetermined luminance BV (TH) (for example, BV10 or less), the luminance determining unit 112 is within the shooting screen obtained by the photometric unit 101. The overall average brightness BV (A) is compared with the brightness BV (C) at the center in the photographing screen to obtain the difference between the overall average brightness BV (A) and the center brightness BV (C).
[0083]
Then, when the brightness determination unit 112 determines that the brightness BV (C) at the center is lower than a predetermined brightness difference (for example, 1 BV), the exposure controller 113 determines the brightness BV (A at the center). ) Based on the average brightness BV (A), the exposure control is performed based on the average brightness BV (A). Do.
[0084]
By performing exposure control as described above, it is possible not only to prevent the main subject such as a person from becoming under when shooting under high brightness, but also to perform appropriate exposure in landscape photography. Can do.
[0085]
According to the camera of the second embodiment, shooting can be performed with an optimum exposure according to the shooting scene.
[0086]
(Third embodiment)
The camera according to the third embodiment has the same configuration as the camera according to the first embodiment described above.
[0087]
FIG. 6 is a flowchart for explaining the procedure of the release sequence of the camera according to the third embodiment configured in the same manner as the camera according to the first embodiment described above.
[0088]
That is, as shown in FIG. 6, first, in step S301, when a power switch of a camera (not shown) is turned on, data such as various setting values and adjustment values are read from the nonvolatile memory 108 such as an EEPROM. A process of expanding in the RAM of the CPU 109 is performed.
[0089]
Next, in step S302, a process for determining whether or not a power switch of a camera (not shown) is off is performed. If it is off, the release sequence is terminated, and if it is on, the process of step S303 is completed. Proceed to processing.
[0090]
Next, in step S303, a determination process is performed to determine whether 1RSW 110 is on. If it is on, the process proceeds to step S304, and if it is off, the process returns to step S302.
[0091]
Next, in step S304, photometric processing is performed, and the average luminance in the photographing screen and the luminance at the center are measured.
[0092]
Next, in step S305, distance measurement processing is performed, and based on distance measurement data of each of the plurality of distance measurement areas in the shooting screen, a main subject is detected by a method such as closest detection to obtain subject distance data. Processing is performed.
[0093]
Next, in step S306, it is determined whether or not the average luminance in the shooting screen obtained in the photometric process in step S304 is higher than a predetermined luminance. If the average luminance is higher than the predetermined luminance, step S307 is performed. The process proceeds to the process of calculating the main subject brightness of the image. If the brightness is low, the process proceeds to step S317.
[0094]
Next, in step S307, a process for calculating the main subject brightness detected in the distance measuring process in step 305 is performed.
[0095]
Next, in step S308, the average luminance in the photographing screen obtained by the photometric processing in step S304 is compared with the main subject luminance calculated in step S307, and the average luminance and the main subject luminance in the photographing screen are compared. If the luminance difference is larger than the predetermined value, the process proceeds to step S309, and if it is smaller, the process proceeds to step S318.
[0096]
Next, in step S309, the main subject brightness calculated in step S307 is selected as exposure calculation data, and processing for making a strobe light emission request is performed.
[0097]
Next, in step S310, a process for calculating exposure control data is performed by performing an exposure calculation based on the luminance information and the strobe light emission request selected in any of step S309 and steps S318 and S319 described later.
[0098]
Next, in step S311, a process of calculating the amount of extension of a focus adjusting lens (not shown) based on the subject distance data obtained in step S305 is performed.
[0099]
Next, in step S312, a process for determining whether or not the 1RSW 110 is on is performed. If it is on, the process proceeds to step S313, and if it is off, the process returns to step S302.
[0100]
Next, in step S313, a process for determining whether or not the 2RSW 111 is on is performed. If it is on, the process proceeds to step S314. If it is off, the process returns to step S312.
[0101]
Next, in step S314, the lens driving unit 103 performs a process of extending a focus adjustment lens (not shown) according to the extension amount obtained in step S311.
[0102]
Next, in step S315, exposure processing is performed by the shutter unit 104 in accordance with the exposure control data obtained in step S310.
[0103]
Next, in step S316, the film feeding unit 105 performs a film one-frame winding process, and then returns to the process in step S302.
[0104]
Next, in step S317, the luminance difference between the average luminance in the photographing screen and the luminance in the central portion is obtained by comparing the average luminance in the photographing screen obtained by the photometric processing in step S304 and the luminance in the central portion. .
[0105]
Here, it is determined whether or not the luminance of the central portion is lower than the predetermined luminance difference. If it is determined that the luminance is low luminance, the process proceeds to step S319, which is the predetermined luminance. If it is determined that the luminance within the difference or the central portion is higher, the process proceeds to step S318.
[0106]
Next, in step S318, a process for selecting the average luminance in the photographing screen obtained by the photometric process in step S304 as exposure calculation data is performed.
[0107]
Next, in step S319, a process for selecting the luminance at the center in the photographing screen obtained by the photometric process in step S304 as exposure calculation data is performed.
[0108]
(Summary of Third Embodiment)
As described above, the camera according to the third embodiment is a camera having the same configuration as that of the camera according to the first embodiment described above. The BV (A) and the luminance BV (C) at the center of the shooting screen are obtained, the distance measuring means 102 measures a plurality of areas including the center area in the shooting screen, and the main subject is selected by a method such as closest selection. To detect subject distance data.
[0109]
Next, the luminance determining unit 112 determines that the average luminance BV (A) in the shooting screen is higher than the predetermined luminance BV (TH) (for example, V10 or more), the distance measuring unit 102. The brightness BV (M) of the main subject detected in step 1 is obtained by the same method as in the first embodiment, and the average brightness BV (A) and the brightness BV (M) of the main subject are compared to compare the overall average brightness BV ( The difference between A) and the luminance BV (C) at the center is obtained.
[0110]
The backlight determining unit 114 and the exposure control unit 113 are backlit when the luminance determining unit 112 determines that the luminance BV (M) of the main subject is lower than a predetermined luminance difference (for example, 1 BV). Then, the flash 106 is caused to emit light and exposure control is performed. When it is determined that the difference is within the predetermined luminance difference, it is determined that the light is not backlit, and exposure control is performed based on the average luminance BV (A).
[0111]
In addition, when it is determined that the average luminance BV (A) is lower than the predetermined luminance BV (TH) (for example, BV10 or less), the luminance determining unit 112 is within the shooting screen obtained by the photometric unit 101. The overall average brightness BV (A) is compared with the brightness BV (C) at the center in the photographing screen to obtain the difference between the overall average brightness BV (A) and the center brightness BV (C).
[0112]
The backlight determining unit 114 and the exposure control unit 113 are backlit when the luminance determining unit 112 determines that the luminance BV (C) at the center is lower than a predetermined luminance difference (for example, 1 BV). The flash 106 is caused to emit light and exposure control is performed. When it is determined that the luminance difference is within the predetermined luminance difference or the luminance BV (C) at the center is higher, it is determined that the backlight is not backlit. Exposure control is performed based on the average luminance BV (A).
[0113]
By performing exposure control as described above, even when it is difficult to determine backlighting by the light metering means 101 due to the influence of stray light, crosstalk, etc., when the background is high brightness and the main subject is backlit, Since the backlight determination is performed based on the relationship between the average luminance BV (A) in the photographing screen measured by the means 101 and the luminance BV (M) of the main subject detected by the distance measuring means 102, the main subject such as a person becomes under. Can be prevented and appropriate exposure can be performed.
[0114]
According to the camera of the third embodiment, when the background is high brightness, whether or not the backlight photographing is performed based on the relationship between the photometric value in the photometric means 101 and the photometric value in the distance measuring means 102. Therefore, exposure control is performed, so that shooting can be performed with an optimum exposure according to the shooting scene.
[0115]
(Fourth embodiment)
The camera according to the fourth embodiment has the same configuration as the camera according to the first embodiment described above.
[0116]
FIG. 7 is a flowchart for explaining the procedure of the release sequence of the camera according to the fourth embodiment configured in the same manner as the camera according to the first embodiment described above.
[0117]
That is, as shown in FIG. 7, first, in step S401, when a power switch of a camera (not shown) is turned on, data such as various setting values and adjustment values are read from the nonvolatile memory 108 such as an EEPROM. A process of expanding in the RAM of the CPU 109 is performed.
[0118]
Next, in step S402, a process for determining whether or not a power switch of a camera (not shown) is off is performed. If it is off, the release sequence is terminated, and if it is on, the process of step S403 is completed. Proceed to processing.
[0119]
Next, in step S403, a process for determining whether or not 1RSW 110 is on is performed. If it is on, the process proceeds to step S404. If it is off, the process returns to step S402.
[0120]
Next, in step S404, photometric processing is performed, and the average brightness and the brightness at the center in the shooting screen are measured.
[0121]
Next, in step S405, distance measurement processing is performed, and based on the distance measurement data of each of the plurality of distance measurement areas in the shooting screen, a main subject is detected by a method such as closest detection to obtain subject distance data. Processing is performed.
[0122]
Next, in step S406, it is determined whether or not the average luminance in the shooting screen obtained in the photometric process in step S404 is higher than a predetermined luminance. If the average luminance is higher than the predetermined luminance, step S407 is performed. The process proceeds to the process of calculating the main subject brightness of the camera. If the brightness is low, the process proceeds to step S417.
[0123]
Next, in step S407, the main subject brightness detected in the distance measurement process in step 405 is calculated, and a backlight determination process is performed based on the subject image data in a plurality of distance measurement areas.
[0124]
Next, in step S408, the process proceeds to step S409 if it is determined that the backlight shooting is performed by the backlight determination in step S407, and the process proceeds to step S418 if it is determined that the backlight shooting is not performed.
[0125]
Next, in step S409, the main subject brightness calculated in step S407 is selected as exposure calculation data, and processing for making a strobe light emission request is performed.
[0126]
Next, in step S410, processing for calculating exposure control data is performed by performing exposure calculation based on the luminance information and the strobe light emission request selected in step S409 and steps S418 and S419 described later.
[0127]
Next, in step S411, a process of calculating the extension amount of a focus adjustment lens (not shown) based on the subject distance data obtained in step S405 is performed.
[0128]
Next, in step S412, a process for determining whether or not the 1RSW 110 is on is performed. If it is on, the process proceeds to step S413, and if it is off, the process returns to step S412.
[0129]
Next, in step S413, a process for determining whether or not the 2RSW 111 is on is performed. If it is on, the process proceeds to step S414, and if it is off, the process returns to step S412.
[0130]
Next, in step S414, the lens driving unit 103 performs a process of extending a focus adjusting lens (not shown) according to the extension amount obtained in step S311.
[0131]
Next, in step S415, exposure processing is performed by the shutter means 104 in accordance with the exposure control data obtained in step S410.
[0132]
Next, in step S416, the film feeding unit 105 performs a film one-frame winding process, and then returns to the process in step S402.
[0133]
Next, in step S417, the luminance difference between the average luminance in the photographing screen and the luminance in the central portion is obtained by comparing the average luminance in the photographing screen obtained by the photometric processing in step S404 and the luminance in the central portion. Then, it is determined whether or not the luminance of the central portion is lower than the predetermined luminance difference. If the luminance is low, the process proceeds to step S419, where the luminance is within the predetermined luminance difference or the luminance of the central portion. If the brightness is higher, the process proceeds to step S418.
[0134]
Next, in step S418, a process for selecting the average luminance in the photographing screen obtained by the photometric process in step S404 as exposure calculation data is performed.
[0135]
Next, in step S419, a process for selecting the luminance at the center in the photographing screen obtained by the photometric process in step S404 as exposure calculation data is performed.
[0136]
(Summary of Fourth Embodiment)
As described above, the camera according to the fourth embodiment is a camera having the same configuration as that of the camera according to the first embodiment described above. First, photometry is performed by the photometry means 101, and the average luminance of the entire shooting screen is determined. The BV (A) and the luminance BV (C) at the center of the shooting screen are obtained, the distance measuring means 102 measures a plurality of areas including the center area in the shooting screen, and the main subject is selected by a method such as closest selection. To detect subject distance data.
[0137]
Next, the backlight determination unit 114 determines that the average luminance BV (A) in the shooting screen is higher than the predetermined luminance BV (TH) by the luminance determination unit 112 (for example, V10 or more). Determines whether the main subject is in a backlight state based on the subject image data detected by the distance measuring means 102.
[0138]
Next, determination of whether or not the main subject is in the backlight state will be described with reference to FIGS.
[0139]
FIG. 8 is a diagram showing an example of a backlight photographing scene and subject image data at that time. FIG. 8A is a backlight photographing scene, and reference numeral 401 in the figure is a person who is a main subject. Reference numeral 402 denotes a distance measuring area in the photographing screen of the distance measuring means 102.
[0140]
FIG. 8B is a diagram showing the relationship between subject image data and each distance measurement area at the time of backlight photographing. Reference numeral 403 in the figure is subject image data, and reference numerals 404, 405, 406. , 407, and 408 are distance measuring areas.
[0141]
FIG. 9 is a diagram showing an example of a follow light shooting scene and subject image data at that time. FIG. 9A shows a follow light shooting scene, and reference numeral 401 in FIG. 9 denotes a person who is a main subject. Reference numeral 402 is a distance measuring area in the photographing screen of the distance measuring means 102.
[0142]
FIG. 9B is a diagram showing the relationship between the subject image data and each distance measurement area at the time of direct light shooting. Reference numeral 403 in the figure is subject image data, and reference numerals 404, 405, Reference numerals 406, 407, and 408 denote distance measurement areas.
[0143]
That is, for example, in the case of a shooting scene where a person 401 as a main subject exists as shown in FIG. 8A, subject image data 403 as shown in FIG. 8B is obtained. The backlight determination means 114 is a subject image of the distance measurement area 405 and the other distance measurement areas 404, 406, 407, and 408 that measure the distance of the person 401 as the main subject based on the determination result by the brightness determination means 112. Comparing the brightness and darkness of the data 401, the distance measurement area 405 of the main subject is lower in luminance than the other distance measurement areas 404, 406, 407, and 408, and therefore is determined to be backlit.
[0144]
In the case of a shooting scene where a person 401 as a main subject exists as shown in FIG. 9A, subject image data 403 as shown in FIG. 9B is obtained, and the main subject is obtained. If only the subject image data 403 of the distance measurement area 407 that measures the distance of the person 401 is viewed, the main subject appears to have a low luminance. However, in reality, such a phenomenon is caused by the influence of sunlight reflected by the automobile in the background. When the contrast of the subject image data 401 of the distance measurement area 407 of the main subject 1 and the other distance measurement areas 404, 405, 406, 408 is compared, the distance measurement area 407 of the main subject Since the luminance difference is small with respect to the regions 404, 405, 406, and 408, the backlight determination unit 114 determines that the backlight is not backlight.
[0145]
When it is determined that the shooting scene is backlit by such backlight determination, exposure control is performed by causing the flash 106 to emit light, and when it is determined that the scene is not backlit, the exposure control unit 113 determines the average brightness. Exposure control is performed based on BV (A).
[0146]
Further, the backlight determination unit 114 and the exposure control unit 113, when the luminance determination unit 112 determines that the average luminance BV (A) is lower than the predetermined luminance BV (TH) (for example, BV10 or less). The average luminance BV (A) of the entire photographing screen obtained by the photometric means 101 and the luminance BV (C) of the central portion of the photographing screen are compared, and the average luminance BV (A) and the central luminance BV (C) are compared. Is determined to be backlight when the brightness BV (C) at the center is determined to be lower than a predetermined brightness difference (for example, 1 BV), and the strobe 106 is caused to emit light to control exposure. When it is determined that the luminance difference is within the predetermined luminance difference or the central luminance BV (C) is higher, it is determined that the backlight is not backlit, and exposure control is performed based on the average luminance BV (A). Do.
[0147]
According to the camera of the fourth embodiment as described above, the backlight determination is performed based on the subject image data. Therefore, it is possible to perform shooting with a more optimal exposure according to the shooting scene.
[0148]
【The invention's effect】
Therefore, as described above, according to the present invention, the conventional technique solves the problem at the time of high-intensity backlight shooting, which is a scene where photometry is difficult, and provides a camera that can take beautiful pictures. be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a main part of a camera of the present invention.
FIG. 2 is a block diagram showing an internal configuration of photometry means 101 in the camera of the present invention.
FIG. 3 is a block diagram showing an internal configuration of the distance measuring means 102 in the camera of the present invention.
FIG. 4 is a flowchart for explaining the procedure of the release sequence of the camera according to the first embodiment of the present invention.
FIG. 5 is a flowchart for explaining the procedure of the release sequence of the camera according to the second embodiment of the present invention.
FIG. 6 is a flowchart for explaining the procedure of the release sequence of the camera according to the third embodiment of the present invention.
FIG. 7 is a flowchart for explaining a procedure of a release sequence of a camera according to a fourth embodiment of the present invention.
FIGS. 8A and 8B are a backlit scene and a scene at that time in order to explain whether or not the main subject is backlit in the fourth embodiment of the present invention. It is a figure which shows an example of subject image data.
FIGS. 9 (a) and 9 (b) are front light shooting scenes and the corresponding scenes in order to explain whether or not the main subject is backlit in the fourth embodiment of the present invention. It is a figure which shows an example of the to-be-photographed object image data.
[Explanation of symbols]
101: Photometric means,
102: Ranging means,
103 ... Lens driving means,
104. Shutter means,
105: Film feeding means,
106 ... Strobe (electronic flash means),
107: Focal length detection means,
108: Non-volatile memory such as EEPROM,
109 ... CPU,
110 ... First release switch (1RSW),
111 ... Second release switch (2RSW),
112 ... brightness determination means,
113 ... Exposure control means,
114. Backlight determination means,
121 ... Photometric lens,
122 ... Average photometric sensor,
123 ... integral control means for photometry,
124: Analog / digital (A / D) conversion means,
125 ... spot metering sensor,
131a, 131b ... light receiving lens,
132a, 132b ... line sensors,
133 ... integration control means for ranging,
134 Reading means.
401 ... a person as a main subject,
402 ... Distance measuring area in the shooting screen,
403 is subject image data,
404, 405, 406, 407, 408... Distance measurement area.

Claims (4)

Photometric means for measuring the average subject brightness in the shooting screen and the subject brightness in the center,
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The exposure control means, when the brightness determination means determines that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness, the distance measurement means Perform exposure control by obtaining the brightness based on the image data of the distance measurement area where the detected main subject exists,
If the luminance determination unit determines that the average luminance of the subject in the shooting screen measured by the photometry unit is lower than the predetermined luminance, the luminance determination unit uses the photometry unit. Comparing the average subject brightness and the central subject brightness to determine the brightness difference between the average subject brightness and the central subject brightness,
It said exposure control means by said brightness determination unit, at lower brightness than the subject brightness is the average object brightness of the central portion, and the difference between the subject brightness of the the average object brightness said central portion is predetermined When it is determined that the brightness difference is greater than the brightness difference, exposure control is performed based on the subject brightness at the center, and the subject brightness at the center is lower than the average subject brightness and the average subject brightness And the central subject brightness is smaller than a predetermined brightness difference or the central subject brightness is determined to be higher than the average subject brightness. A camera that performs exposure control based on subject brightness. Photometric means for measuring the average subject brightness in the shooting screen and the subject brightness in the center,
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The brightness determining means, when the brightness determining means determines that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness, the distance measuring means Determine the brightness of the main subject based on the image data of the detected ranging area where the main subject exists,
The exposure control means, when the brightness determination means determines that the difference between the average subject brightness measured by the photometry means and the brightness of the main subject measured by the distance measurement means is smaller than a predetermined value, When the average brightness of the subject by the metering means is determined to be large, exposure control is performed by the brightness of the main subject by the distance measuring means,
If the luminance determination unit determines that the average luminance of the subject in the shooting screen measured by the photometry unit is lower than the predetermined luminance, the luminance determination unit uses the photometry unit. Comparing the average subject brightness and the central subject brightness to determine the brightness difference between the average subject brightness and the central subject brightness,
It said exposure control means by said brightness determination unit, at lower brightness than the subject brightness is the average object brightness of the central portion, and the difference between the subject brightness of the the average object brightness said central portion is predetermined When it is determined that the brightness difference is greater than the brightness difference, exposure control is performed based on the subject brightness at the center, and the subject brightness at the center is lower than the average subject brightness and the average subject brightness wherein when the difference between the central portion of the subject luminance is determined as toward the object luminance less than or the middle than the predetermined brightness difference is the average luminance higher than the subject luminance is such the average and A camera that performs exposure control based on subject brightness. Photometric means for measuring the average subject brightness in the shooting screen and the subject brightness in the center,
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Electronic flash means for illuminating the subject during shooting,
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The brightness determining means detects by the distance measuring means when it is determined by the brightness determining means that the average subject brightness in the shooting screen measured by the photometry means is higher than a predetermined brightness. The luminance of the main subject is determined based on the image data of the distance measurement area where the main subject exists,
The exposure control means is configured such that the brightness of the main subject measured by the distance measuring means is higher than the average subject brightness measured by the photometry means or higher than the average subject brightness measured by the brightness determination means. Exposure control is performed based on the average subject brightness by the photometry means when it is determined that the difference between the brightness of the main subject and the main subject is smaller than a predetermined value. Control exposure,
The brightness determination means, by the luminance determining means, when said average luminance of the object photographed screen is determined to be a luminance lower than the predetermined luminance, the average object brightness by said photometry means Compare the subject brightness in the center to determine the brightness difference between the average subject brightness and the subject brightness in the center,
It said exposure control means by said brightness determination unit, at lower brightness than the subject brightness is the average object brightness of the central portion, and the difference between the subject brightness of the the average object brightness said central portion is predetermined When it is determined that the brightness difference is greater than the brightness difference, exposure control is performed based on the subject brightness at the center, and the subject brightness at the center is lower than the average subject brightness and the average subject brightness And the central subject brightness is smaller than a predetermined brightness difference or the central subject brightness is determined to be higher than the average subject brightness. A camera that performs exposure control based on subject brightness. Photometric means for measuring the average subject brightness in the shooting screen and the subject brightness in the center,
Ranging means for detecting a main subject by measuring a plurality of areas including a central portion in the shooting screen;
Electronic flash means for illuminating the subject during shooting,
Brightness determination means for determining an average subject brightness in the photographing screen and a subject brightness in the center based on at least a measurement result by the photometry means;
Back light determination means for performing back light determination of a photographic scene based on a determination result by the brightness determination means;
In a camera having at least exposure control means for performing exposure control based on a determination result by the brightness determination means,
The backlight determining unit determines that the distance determining unit determines that the average determining unit within the shooting screen measured by the photometric unit has a luminance higher than a predetermined luminance by the luminance determining unit. Based on the image data of each distance measurement area, make a backlight determination,
The exposure control unit performs exposure control based on an average photometric value obtained by the photometry unit when the backlight determination unit determines that the backlight is not backlit, and causes the electronic flash unit to emit light when it is determined that the backlight is backlit. Done
The brightness determination means determines the average by the photometry means when the brightness determination means determines that the average subject brightness in the shooting screen measured by the photometry means is lower than the predetermined brightness. Comparing the average subject brightness and the central subject brightness to obtain a brightness difference between the average subject brightness and the central subject brightness,
It said exposure control means by said brightness determination unit, at lower brightness than the subject brightness is the average object brightness of the central portion, and the difference between the subject brightness of the the average object brightness said central portion is predetermined When it is determined that the brightness difference is greater than the brightness difference, exposure control is performed based on the subject brightness at the center, and the subject brightness at the center is lower than the average subject brightness and the average subject brightness And the central subject brightness is smaller than a predetermined brightness difference or the central subject brightness is determined to be higher than the average subject brightness. A camera that performs exposure control based on subject brightness.

Images