JP2001318399A - Photometric device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photometric device by which a photometric error due to the manufacturing error of a camera is highly accurately corrected. SOLUTION: A photometric arithmetic part 43 calculates the luminance of a field based on the lens data of an attached lens and a photometric data outputted by a photometric element 6. An individual data storing part 44 stores a data corresponding to a deviation from the design specification of a photometric optical system 40 at a manufacturing stage for each camera. A photometric correcting/calculating part 45 calculates a luminance correcting amount based on a lens data and an individual data by using an operation expression obtained by previously analyzing a relation between the deviation value and the luminance correcting amount and corrects the luminance of the field.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric device for a single-lens reflex camera provided with a photographic lens, and more particularly to a photometric device for a camera having an improved photometric correction method.

[0002]

2. Description of the Related Art Conventionally, as a photometric device of a single-lens reflex camera,
A luminous flux that has passed through the taking lens is measured by a photometric element provided in a finder optical system to calculate the field brightness, so-called TT.
2. Description of the Related Art An L photometry type photometry device is known. Further, there is also known a photometric device of a divided photometric method in which a light receiving portion of a photometric element is divided into a plurality of regions and photometry is performed for each divided photometric region. In such a conventional TTL metering type photometric device, an error occurs in the calculated field brightness due to factors such as the optical characteristics of the taking lens, that is, the open F value, the exit pupil position (distance), or the position of the divided photometric region. Therefore, the field brightness is corrected for each divided photometry area according to the optical characteristics of the photographing lens. In addition, errors in the field brightness also occur due to individual factors of the camera such as a manufacturing error of the photometric optical system interposed between the photographing lens and the photometric element. Japanese Patent Application Laid-Open No. H11-249193 discloses a method for removing an error due to a camera-specific factor such as a manufacturing error of a photometric optical system. According to this method, first, a subject having a known luminance is subjected to photometry for each camera body using at least two reference lenses having different open F-numbers to calculate a field luminance, and the subject luminance calculated as the known luminance is calculated. An error from the scene brightness is stored in the body storage unit. When the photographing lens is actually mounted, the actual luminance error amount is estimated from the stored at least two pieces of luminance error data and the open F value of the mounted photographing lens, and the luminance of each camera is corrected.

[0003]

Problems to be Solved by the Invention
In Japanese Patent No. 93, the influence of an error factor of each camera (such as a manufacturing error of a photometric optical system) is stored in the form of a luminance error amount which is a final calculation result. In this method, the correction of the field brightness is performed, assuming that it depends on the camera. However, this method takes into account the characteristics and mechanism that the error factors of the individual cameras (such as the manufacturing error of the photometric optical system) give to the brightness error. Since the correction was rough without performing the correction, the correction of the luminance error was insufficient. Also, the error amount of the field luminance caused by the individual difference of the photometric optical system is:
In addition to the F-number of the taking lens, factors such as the exit pupil position of the taking lens and the factors on the camera body side change intricately as factors on the taking lens side.
When the brightness correction was performed only in relation to the value, the brightness correction could not always be performed with sufficient accuracy. The object of the present invention is to correct the camera-specific luminance calculation error with higher accuracy by appropriately considering the error factor of the camera-specific photometric optical system that causes the calculation error of the field luminance. It is to do.

[0004]

According to a first aspect of the present invention, there is provided a photometric device for a camera, which outputs photometric data in accordance with the amount of received light.
And transmitting the light transmitted through the photographing lens to the photometric element (6).
Optical system (40), a lens data output unit (42) for outputting lens data representing the optical characteristics of the photographic lens, and photometry for calculating the field brightness based on the photometric data and the lens data. An arithmetic unit (43); a rewritable individual data storage unit (44) for storing information relating to a deviation from the design specification of the photometric optical system (40) as individual data for each camera; A photometric correction operation unit (45) for applying a camera-specific luminance correction to the field luminance calculated by the photometric operation unit (43) based on the data. According to a second aspect of the present invention, in the photometric device for a camera according to the first aspect, the photometric correction calculation unit (45) includes a deviation amount from a design specification of the photometric optical system (40) and a subject resulting therefrom. The method is characterized in that the luminance correction amount is calculated based on the relationship between the field luminance error amount. According to a third aspect of the present invention, in the photometric device for a camera according to the first aspect, an optical axis of the photometric optical system (40) is set to be at a predetermined angle with an optical axis of the photographing lens. The data is data relating to an angular deviation of each camera from the predetermined angle. According to a fourth aspect of the present invention, in the photometric device for a camera according to the first aspect, the lens data includes data relating to a distance of an exit pupil of a photographic lens, and the photometric correction calculation unit (45) includes the photographic lens. The calculation is performed such that the smaller the distance of the exit pupil becomes, the larger the absolute amount of the luminance correction of each camera becomes.

[0005]

Embodiments of the present invention will now be described in further detail with reference to the drawings. (Configuration of Photometric Device) FIG. 1 is a block diagram showing an embodiment of a photometric device for a camera according to the present invention. A camera to which the photometric device of this embodiment is applied includes a photometric optical system 40.
, A photometry element 6, a photometry calculation unit 43, a lens data output unit 42, an individual data storage unit 44, a photometry correction calculation unit 45, and the like. The photometric optical system 40 is an optical system arranged between the photometric element 6 and the taking lens 1. The photometric element 6 is an element having a plurality of divided photometric areas and outputting photometric data according to the amount of light received in each divided photometric area.
The lens data output unit 42 outputs lens data representing the optical characteristics of the taking lens. The individual data storage unit 44 stores data relating to the deviation amount from the design specification of the photometric optical system 40 for each camera described later. The photometric calculation unit 43 is a unit that calculates the field brightness from the photometric data output by the photometric element 6 and the lens data output by the lens data output unit 42. The photometric correction calculation unit 45 uses the individual data input from the individual data storage unit 44 and the lens data output by the lens data output unit 42 to generate a luminance correction value for individually correcting the field luminance for each camera body. This is a part that calculates and corrects the field luminance calculated by the photometry calculation unit 43 based on the luminance correction value. On the basis of the field luminance thus obtained, the camera determines an appropriate exposure value as is well known, and further determines a shutter value and an aperture value to control the photographing operation. FIG. 2 is a diagram showing a basic configuration when the present invention is applied to a photometric device of a single-lens reflex camera. An interchangeable lens structure 10 is mounted on a camera body 20. The interchangeable lens structure 10 includes a photographing lens 1, a lens microcomputer 11, and a lens ROM 12. The camera body 20 includes a quick return mirror 2, a condenser lens 9, A screen 3, a pentaprism 4, a photometric lens 5, a photometric element 6, an eyepiece 7, a body microcomputer 21, a body ROM 22, and an EEPROM 23 are provided. Quick return mirror 2, condenser lens 9, screen 3, pentaprism 4, photometric lens 5 disposed from the taking lens 1 to the photometric element 6
And the like correspond to the photometric optical system 40 in FIG. The lens microcomputer 11 and the lens ROM 12 correspond to the lens data output unit 42 in FIG.
Corresponds to the individual data storage unit 44. Further, the body microcomputer 21 and the body ROM 22 correspond to the photometry calculation unit 43 and the photometry calculation unit 45 in FIG. The lens microcomputer 11 and the body microcomputer 21 exchange information with each other via the connector 8. (Configuration of Photometric Optical System) FIG. 3 is a configuration diagram showing a specific configuration of the photometric optical system 40 and the photometric element 6.
The photometric element 6 and the photometric lens 5 are located at positions off the optical axis of the taking lens 1 and the eyepiece 7. Here, as the most general example, the description will be made on the assumption that the photometric lens 5 and the photometric element 6 are placed above the eyepiece 7.
The optical axis 13 of the photometric optical system (the optical axis of the photometric lens 5) is designed to intersect with the optical axis 14 of the photographing lens 1 on the screen 3 at a predetermined angle (hereinafter referred to as the glare angle of the photometric optical system). I have. Therefore, the photometric element 6 looks at the screen 3 obliquely. The predetermined angle (glare angle) is set to a value determined as a design specification of the photometric optical system. Light from the subject passes through the taking lens 1, is reflected by the quick return mirror 2 toward the finder side, passes through a condenser lens 9 formed of a Fresnel lens provided on the back surface of the screen 3, and is then placed at a position equivalent to the film surface. An image is formed on the screen 3 once. A part of the light beam that has passed through the screen 3 and diffused is bent by the pentaprism 4 and enters the eye of the photographer through the eyepiece 7. A part of the light beam that has passed and diffused through the screen 3 is condensed by the photometric lens 5 and re-images on the photometric element 6. FIG. 4 is a diagram showing a light receiving section of the photometric element 6. The light receiving portion of the photometric element 6 is divided into several SPDs (silicon photodiodes) (in FIG. 4, divided into five), so that the object field can be divided and each area can be photometrically measured. That is, optically, the divided shape of the light receiving portion of the photometric element 6 is configured to be superimposed on the screen on the screen 3 by the photometric lens 5, and the screen can be divided into a plurality of divided photometric areas to perform photometry. It is possible. The light beam diffused by the screen 3 is condensed by the photometric lens 5 and forms an image once formed by the screen 3 on the photometric element 6 again. In the divided photometry area on the photometry element 6, a photocurrent corresponding to the illuminance of the image is generated in the SPD, the current is logarithmically compressed, amplified, and the like, and A / D converted by the A / D converter in the body microcomputer 21. . By performing calculations such as gamma correction and level correction in the body microcomputer 21, photometric data corresponding to the illuminance of each divided photometric area on the photometric element 6 is obtained. FIG. 5 is a diagram showing the diffusion characteristics of light diffused by the screen 3 (the relationship between the angle of the diffused light and the relative intensity of the diffused light). The solid line in FIG. 5 shows an example of the diffusion characteristics of light diffused by the screen 3 when the photographing lens is attached. The incident angle characteristic of the light incident on the screen 3 changes according to the open F value of the mounted photographing lens 1, the exit pupil position, and the position of the divided photometry area, and accordingly, the diffusion of the light diffused by the screen 3. The characteristics are also the open F value, the exit pupil position,
It changes depending on the position of the divided photometry area and the like. The amount of light received by the photometric element 6 is the sum of components diffused in the direction of the photometric lens 5 among all the light incident on the screen 3 diffused in various directions. Therefore, the amount of light received by the photometric element 6 and the photometric data corresponding to the photometric data include the divided photometric area, the degree of diffusion of the screen, the open F value of the taking lens, the exit pupil position, The glare angle of the system changes in a complicated manner. In order to accurately calculate the field luminance from the photometric data, it is necessary to correct the luminance in consideration of the above change. (Embodiment of the photometric calculation unit) As described above, the photometric data obtained for each of the divided photometric areas includes the open F value of the photographing lens 1, the exit pupil position, the degree of diffusion of the screen 3, and the It is affected by factors such as the glare angle and the position of the divided photometry area. The photometric calculation unit 43 calculates the field luminance from which the influence of these factors has been removed. The body ROM 22 that constitutes the photometry calculation unit 43 stores a calculation formula derived in advance for calculating the field luminance from the lens data and the photometry data, and the body microcomputer 21 performs processing based on the calculation formula. Calculate the field brightness. An example of a method of calculating the field luminance by the photometric calculation unit 43 will be described. First, a reference camera body including a photometric optical system and a photometric element 6 having the same configuration state as that of a mass-produced product is prepared for each camera body model.
In this reference camera body, the components of the photometric optical system use those that are central to manufacturing variations, and the adjustment of each component is adjusted to the vicinity of the center of the adjustment tolerance. Even if the specifications of the photometric optical system of the reference camera body slightly deviate from the design values on the drawing, the specifications of the photometric optical system of the reference camera body can be considered to be the design specifications.
That is, the design specification of the photometric optical system referred to here is the specification of the photometric optical system used to derive the reference subject luminance, and can also be referred to as the reference specification of the photometric optical system. Next, a plurality of types of photographing lenses are mounted on the reference camera body, photometric data is taken for each of the divided photometric areas of the photometric element 6 for a subject having a known luminance (such as a luminance box), and the photometric data is stored in a predetermined manner. The luminance is converted into the field luminance based on the relational expression. At this time, the amount of light incident on the photometric element 6 is limited by the size of the aperture of the attached lens (open F value).
The field brightness is corrected according to the value. The amount of light received by the photometric element 6 is also affected by the diffusion characteristics of the light diffused by the screen 3 as described above, so that the optical characteristics such as the open F value of the taking lens and the exit pupil distance that affect the diffusion characteristics are affected. It is necessary to correct the field luminance accordingly. This correction is performed as follows. First, an error amount of the calculated field luminance with respect to the known luminance is obtained. Next, the correspondence between the error amount and the lens data of the mounted photographing lens (open F value, exit pupil position, focal length, etc.) is analyzed by a neuro-technique or the like, and the luminance error amount is calculated for arbitrary lens data. An operation expression to be performed is derived. The luminance error amount calculation formula obtained for the reference camera body in this way is stored as a program in the ROM 22 of the body microcomputer in the camera body 20. When the interchangeable lens structure 10 is actually mounted on the camera body 20, the body microcomputer 21 first calculates the field brightness based on the photometric data and the open F value obtained by communication with the lens microcomputer 11. Next, a luminance error amount is calculated using the lens data and the above-described luminance error amount calculation expression, and the field luminance is corrected based on the error amount. The above is an example of the calculation of the field luminance based on the photometric data, which is the process performed by the photometric calculation unit 43 in FIG. (Embodiment of Photometric Correction Computing Unit) By performing the above-described processing, the field luminance is calculated from the photometric data output from the photometric element 6. The field luminance is determined by the individual camera bodies. This is the field luminance calculated on the assumption that the configuration is exactly the same as that of the reference camera body. Actually, individual differences due to manufacturing errors and adjustment errors occur in the photometric optical system of each camera body. For example, errors in adjusting the angle of the quick return mirror 2, manufacturing variations in the diffusivity of the screen 3 and the focal length of the condenser lens 9, manufacturing variations in the apex angle of the pentaprism, errors in the focal length of the photometric lens 5, and photometry for the screen 3. The error includes a glare angle adjustment error of the optical system, a position adjustment error of the photometric element 6, and the like.
As described above, if the configuration state of the photometric optical system of each camera body deviates from the configuration state (design specification) of the photometric optical system of the reference camera body, the photometric calculation unit 4 of FIG.
An error occurs between the field luminance calculated in step 3 and the actual field luminance. Here, the design specifications of the photometric optical system are, specifically, the design value of the glancing angle of the photometric optical system, the reference dimensions of the components constituting the photometric optical system, the specifications of the members constituting the photometric optical system (the diffusion degree of the screen). , The transmittance of the photometric optical system, etc.). An error generation mechanism of the field luminance will be described by taking as an example a factor of the glare angle of the photometric optical system which has a large influence on the field luminance. In FIG. 3, the angle (glare angle) between the optical axis 13 of the photometric lens 5 and the optical axis 14 of the photographing lens 1 is represented by α. The optical axis 14 indicates the optical axis position when the photometric optical system 40 is in accordance with the design specification (design value or center value of adjustment error). Next, it is assumed that the optical axis 14 of the photographing lens 1 is shifted by the angle θ and becomes the optical axis 14 ′. The angle between the optical axis 14 'of the taking lens 1 and the optical axis 13 of the photometric lens 5 changes from α by θ. Is caused by manufacturing variations in the shape of the pentaprism 4, errors in adjusting the inclination of the quick return mirror 2, errors in adjusting the positions of the photometric lens 5 and the photometric element 6, and variations in dimensions of camera body parts. Since the amount of light condensed by the photometric lens depends on the glancing angle α, if this changes by θ, the amount of light diffused in the direction of the photometric lens 5 changes as described above. When the diffusion characteristic of the diffused light by the screen 3 is as shown by the solid line in FIG. 5, the angle α and the angle α + θ
The change in the amount of diffusion of light is sharp, and as a result, the shift in the glancing angle of the photometric optical system has a great effect on the amount of light received by the photometric element 6 and thus on the calculated field luminance. For example, when the diffusion degree of the screen 3 is high and the open F value is bright, the diffusion characteristic of the light diffused from the screen 3 comprehensively becomes a relatively wide diffusion characteristic as shown by a broken line in FIG. The change in the amount of light diffusion with respect to the deviation is gradual. However, recently, in order to brighten the viewfinder, the diffusion degree of the screen 3 has been set to be low.
When combined with a dark lens having a large value, the diffusion characteristic of light diffused from the screen 3 becomes steep.
Therefore, the change in the amount of light diffusion with respect to the shift of the glare angle of the photometric optical system becomes sharp, and the individual difference of the calculated field luminance becomes a nonnegligible amount. Although FIG. 3 shows the central region of the screen 3, the amount of light diffused similarly changes in the peripheral region.
Also, the amount of change in the diffused light differs for each region. The photometry correction calculation unit 45 corrects the brightness calculation error due to the individual difference of the photometry optical system for each camera with respect to the field brightness calculated by the photometry calculation unit 43. In the present invention, the arithmetic expression for calculating the luminance correction amount for each individual is stored in the body ROM 22 in the camera body 20 in advance. The deviation from the design specification of the photometric optical system 40 is stored in a rewritable storage device such as the EEPROM 23 as individual data corresponding to the deviation.
Rewrite individually for each camera when assembling and adjusting. The arithmetic expression for calculating the luminance correction amount has the following characteristics. The degree of change of the luminance correction amount is changed according to the divided photometry area. This is because the diffusion characteristics of the diffused light differ depending on the position in the divided photometry area. As 1 / Po increases, the correction amount increases. (Po
Is the exit pupil distance of the photographing lens. Therefore, as Po decreases, the correction amount increases. This is because, as the exit pupil distance becomes shorter, the angle of incidence of light entering the peripheral portion of the screen becomes steeper, and light at the foot of the diffusion characteristic is used for photometry. As the open F-number of the taking lens increases (darkens), the correction amount increases. This is because the darker the open F value, the steeper the diffusion characteristic of the diffused light. these,
Are assumed that the change in the amount of light received by the photometric element for each camera body is mainly caused by a shift in the angle (glare angle) between the optical axis 13 of the photometric lens 5 and the optical axis 14 of the photographic lens 1. Guided by that. The following calculation can be considered as an example of a calculation expression having the above characteristics.

[0006]

(Equation 1)

Here, S [i]: luminance correction amount in each divided photometry area θ: adjustment value recorded in a rewritable storage device such as an EEPROM K [i]: defines the degree of effectiveness of luminance correction for each divided photometry area Coefficient Po: distance of exit pupil of photographing lens AV: logarithm of base 開放 2 of open F value of photographing lens A, B, C, D: positive constant i: number indicating area of divided photometric area. In this example,
5. θ is a value indicating the above-mentioned angle shift amount, which is recorded in a rewritable storage device and is individual data representing characteristics of each camera body individual. Since K [i] requires a different degree of this correction for each divided photometry area, the coefficient is different for each area. When the photometric lens 5 and the photometric element 6 are arranged above the eyepiece 7, the change in the amount of diffused light for each camera body is larger in the divided photometric area corresponding to the lower side of the shooting screen. Therefore, the value of K [i] also becomes large in the divided photometry area corresponding to the lower side of the shooting screen.
K [i] for the divided photometry area corresponding to the upper side of the shooting screen
May be small, this correction may be omitted according to the situation. Po and AV are calculated from the transmitted lens data. The values of A, B, C, and D are calculated by Equation 1 after attaching various lenses, analyzing the relationship between the glancing angle and the error amount of the field luminance calculated by the photometric calculation unit through experiments. It is determined that the difference from the error amount is minimized. The value of the glancing angle shift amount θ is obtained by measurement with a collimator or the like at the time of assembling and adjusting the camera, and a value different for each camera body is written as an adjustment value in an EEPROM or the like. Alternatively, based on a predetermined reference lens and a predetermined field luminance, a correspondence table representing the relationship between the shift amount of the glare angle θ and the calculated field luminance is experimentally obtained, and the predetermined field luminance is determined. In order to obtain the calculated field luminance when the reference lens and the individual camera body are combined, the correspondence table is reversely looked up from the field luminance to obtain the shift amount θ of the glare angle. Is also good. At this time, the larger the number of lenses used, the more statistically correct the value of θ can be obtained. However, since the adjustment work is increased, the number of lenses may be determined in consideration of the balance between the two. Using the luminance correction amount obtained by Expression 1, the final field luminance is calculated by Expression 2
Is required.

[0008]

(Equation 2)

Here, Bv [i]: field luminance of each divided photometry area G [i]: field luminance obtained by the photometry calculation unit 43 S [i]: luminance correction amount i: area of the divided photometry area A number representing. In this example,
5. FIG. 6 is a flowchart showing a photometric calculation routine of the photometric device for a camera according to the present invention. The photometric calculation routine according to the present embodiment performs the calculations of the photometric calculation unit 43 and the photometry correction calculation unit 45, and is performed by the body microcomputer 21. In S101, the body microcomputer 21
The photometric data is read from the photometric element 6. In S102, the body microcomputer 21 reads the lens data from the lens microcomputer 11 built in the interchangeable lens structure 10. This also includes data such as the F-number of the photographing lens, the size / distance of the exit pupil, and the focal length, which are used in subsequent calculations. In S103, the body microcomputer 21
Calculates the field luminance G [i] for each photometric divided region by neuro-operation using the photometric data and the lens data. In step S104, the body microcomputer 21
The deviation amount θ of the glare angle of the photometric optical system F40 from the ROM 23
Read the individual data corresponding to. In S105,
The body microcomputer 21 calculates the luminance correction amount S [i] from the individual data and the lens data, corrects it in addition to the field luminance G [i], and obtains the final field luminance Bv [i]. (Modifications) The present invention is not limited to the embodiments described above, and various modifications and changes are possible. The individual data representing the characteristics of each camera is not limited to the amount of deviation θ of the glancing angle of the photometric optical system 40. For example, the photographing optical axis 14 and the photometric optical axis 13 on the screen 3
And the positional deviation of the divided photometry area with respect to the photographing screen, and the deviation from the design value of the diffusivity for each mold cavity when the screen 3 is made of a plastic molded product. Data may be used. As individual data relating to the amount of deviation θ of the glare angle of the photometric optical system 40, for example, a dimensional error of the pentaprism 4, an apex angle error, an angle adjustment error of the quick return mirror 2, and the like are directly measured and stored. You may. Further, the individual data is not limited to one type, and a plurality of types of data such as the amount of deviation of the glare angle of the photometric optical system and the amount of deviation of the position of the divided photometric region with respect to the shooting screen may be used simultaneously. The calculation formula of the brightness correction amount by the brightness correction calculation unit 45 is as follows:
However, the present invention is not limited to this, and may be an arithmetic expression representing the characteristic relationship between the deviation from the design specification of the photometric optical system 40 and the luminance correction amount, and can be obtained theoretically or experimentally. The photometric device of the camera according to the present invention is a photometric optical system 4.
Since the correction of individual camera variations of 0 is performed, the present invention can be applied not only to a camera of an interchangeable lens system but also to a camera with a built-in photographic lens as long as it is a photometric device that performs photometry via the photographic optical system 1. It is.

[0010]

As described above, according to the present invention,
Measure the deviation amount of each camera from the design specifications of the photometric optical system of the camera, and calculate the luminance correction amount from the relationship between the deviation amount and the luminance error amount which are determined in advance in consideration of the characteristics of the photometric optical system and the error generation mechanism. With this configuration, the field brightness can be individually corrected in consideration of manufacturing errors for each camera, enabling more fine-grained correction compared to the past, enabling highly accurate calculation of the field brightness become.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram schematically showing a photometric device of the camera.

FIG. 3 is a diagram showing a basic configuration of a photometric optical system.

FIG. 4 is a diagram showing a divided shape of a photometric element.

FIG. 5 is a diagram showing diffusion characteristics of light diffused by a screen.

FIG. 6 is a flowchart illustrating a photometry calculation routine of the embodiment of the camera photometry device according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 shooting lens 5 photometric lens 6 photometric element 11 lens microcomputer 12 lens ROM 21 body microcomputer 22 body ROM 23 EEPROM 40 photometric optical system 42 lens data output unit 43 photometric calculation unit 44 individual data storage unit 45 photometric correction calculation unit

Claims (4)

[Claims] 1. A photometric device for a camera for measuring the brightness of an object scene by measuring light from the scene transmitted through a photographing lens, wherein a photometric element for outputting photometric data according to the amount of received light; A photometric optical system that guides light transmitted through the lens to the photometric element, a lens data output unit that outputs lens data representing the optical characteristics of the photographing lens, and a field brightness based on the photometric data and the lens data. A photometric calculation unit for calculating; a rewritable individual data storage unit for storing information relating to deviations from the design specifications of the photometric optical system as individual data for each camera; and the photometry based on the individual data and the lens data. A photometric correction device for a camera, comprising: a photometric correction operation unit that applies a camera-specific luminance correction to the field luminance calculated by the arithmetic unit. 2. A photometric device for a camera according to claim 1, wherein said photometric correction calculation unit calculates a difference between a deviation from a design specification of said photometric optical system and an error of subject field luminance resulting from the deviation. A photometric device for a camera, which calculates a luminance correction amount based on a relationship between the two. 3. A photometric device for a camera according to claim 1, wherein an optical axis of said photometric optical system is set at a predetermined angle with an optical axis of said photographing lens, and said individual data is said predetermined angle. A photometric device for a camera, characterized in that the data is data on an angular deviation of each camera from the camera. 4. A photometric device for a camera according to claim 1, wherein said lens data includes data relating to a distance of an exit pupil of a photographic lens, and said photometric correction calculation section includes a distance of an exit pupil of said photographic lens. Is smaller,
A photometric device for a camera, which performs an operation to increase the absolute amount of luminance correction for each camera.