JPS5796318A - Automatic exposure control device of ttl direct photometric camera - Google Patents
Automatic exposure control device of ttl direct photometric cameraInfo
- Publication number
- JPS5796318A JPS5796318A JP17245280A JP17245280A JPS5796318A JP S5796318 A JPS5796318 A JP S5796318A JP 17245280 A JP17245280 A JP 17245280A JP 17245280 A JP17245280 A JP 17245280A JP S5796318 A JPS5796318 A JP S5796318A
- Authority
- JP
- Japan
- Prior art keywords
- front curtain
- photographed
- luminance
- difference
- reflectance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
- G03B7/08—Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
- G03B7/081—Analogue circuits
- G03B7/083—Analogue circuits for control of exposure time
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Exposure Control For Cameras (AREA)
Abstract
PURPOSE:To prevent influence by the difference between reflectance of a front curtain and a film surface, by controlling the exposure integration through a logarithmic expanding transistor in accordance with the difference between the photodetecting quantity by a reflection from the front curtain which has been compressed logarithmically, and the photodetecting quantity before traveling of the front curtain is completed. CONSTITUTION:When a rise of a mirror is completed, a reflected ray corresponding to the luminance of an object to be photographed, from a front curtain is photodetected by photoelectric converting element 4, and logarithmic compressive voltage is held by a capacitor 16. Subsequently, when the front curtain starts traveling, a reflected ray from a film surface is also photodetected, an output of the circuit 14 is varied, and is compared with holding voltage of the capacitor 16 by a substracting circuit 24 provided with an operational amplifier 19, etc. This compared output passes through a gate 26 which is opened in case when the luminance of an object to be photographed is large, controls a logarithmic expanding transistor 31, discharge of a capacitor 32 is adjusted, and the quantity of integration corresponding to the luminance of the object to be photographed, through an operational amplifier 33, etc. becomes a value which has corrected the difference between reflectance of the front curtain and the film. Even in case when the luminance of the object to be photographed is small, the same result is obtained, and a suitable exposure is executed automatically without being inflenced by the difference of reflectance between the front curtain and the film.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17245280A JPS5796318A (en) | 1980-12-05 | 1980-12-05 | Automatic exposure control device of ttl direct photometric camera |
| US06/322,853 US4408852A (en) | 1980-12-05 | 1981-11-19 | Automatic exposure controller for camera of TTL direct photometry type |
| FR8122159A FR2495790A1 (en) | 1980-12-05 | 1981-11-26 | AUTOMATIC EXPOSURE CONTROL DEVICE FOR DIRECT PHOTOMETRY TYPE PHOTOGRAPHIC APPARATUS THROUGH THE OBJECTIVE |
| GB8136580A GB2090005B (en) | 1980-12-05 | 1981-12-04 | Improvements in or relating to automatic exposure controllers for cameras of ttl direct photometry type |
| DE3148071A DE3148071C2 (en) | 1980-12-05 | 1981-12-04 | Automatic exposure device for a camera with light measurement through the lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17245280A JPS5796318A (en) | 1980-12-05 | 1980-12-05 | Automatic exposure control device of ttl direct photometric camera |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5796318A true JPS5796318A (en) | 1982-06-15 |
Family
ID=15942240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17245280A Pending JPS5796318A (en) | 1980-12-05 | 1980-12-05 | Automatic exposure control device of ttl direct photometric camera |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5796318A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0642100A (en) * | 1992-05-13 | 1994-02-15 | Misawa Homes Co Ltd | Support hardware for eaves soffit material |
-
1980
- 1980-12-05 JP JP17245280A patent/JPS5796318A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0642100A (en) * | 1992-05-13 | 1994-02-15 | Misawa Homes Co Ltd | Support hardware for eaves soffit material |
| JP2688305B2 (en) * | 1992-05-13 | 1997-12-10 | ミサワホーム株式会社 | Eave ceiling material support structure |
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