JPS5651726A - Photometric system - Google Patents
Photometric systemInfo
- Publication number
- JPS5651726A JPS5651726A JP12779379A JP12779379A JPS5651726A JP S5651726 A JPS5651726 A JP S5651726A JP 12779379 A JP12779379 A JP 12779379A JP 12779379 A JP12779379 A JP 12779379A JP S5651726 A JPS5651726 A JP S5651726A
- Authority
- JP
- Japan
- Prior art keywords
- photocurrent
- controlling
- amplification
- photometry
- vb2s
- 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.)
- Granted
Links
Landscapes
- Exposure Control For Cameras (AREA)
Abstract
PURPOSE: To enable accurate photometry to be performed with simple circuits by performing memory type photometry in such a manner that the integrated current for exposure determination becomes equal to an initial value until shutter curtains become fully open and controlling exposure by the use of the photocurrent amplification factor information outputted in the final after the full opening.
CONSTITUTION: A mirror up signal causes a mirror to start ascending. When it ends ascending, the photocurrent amplification information Va having been stored in a microcomputer 11 is inputted from the DA converter 12 of an amplification control circuit 4 to a constant current circuit 2 which in turn supplies the current IREF to a photocurrent amplifying circuit 1, thereby controlling the amplification factor. The substituting characteristic value VB2 determined by the IREF and the photocurrent Ii from a silicon photodiode SPD is sampled (n) times by way of an AD converter 13, and its mean value VB2S is determined. When the front curtain starts traveling, a transistor Q5 is turned OFF by a switching driver 7, by which integration is started and Va is outputted so that VB2 becomes equal to VB2S. After the full opening, controlling is performed by using the final Va. Thereby, the accurate photometry may be performed with the simple circuits.
COPYRIGHT: (C)1981,JPO&Japio
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12779379A JPS5651726A (en) | 1979-10-03 | 1979-10-03 | Photometric system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12779379A JPS5651726A (en) | 1979-10-03 | 1979-10-03 | Photometric system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5651726A true JPS5651726A (en) | 1981-05-09 |
| JPS6138454B2 JPS6138454B2 (en) | 1986-08-29 |
Family
ID=14968809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12779379A Granted JPS5651726A (en) | 1979-10-03 | 1979-10-03 | Photometric system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5651726A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56138726A (en) * | 1980-03-31 | 1981-10-29 | Olympus Optical Co Ltd | Photometric apparatus |
| JPS5828827U (en) * | 1981-08-18 | 1983-02-24 | オリンパス光学工業株式会社 | Camera reflection photometry device |
| JPS58189619A (en) * | 1982-04-02 | 1983-11-05 | イ−ストマン コダック カンパニ− | Photographic camera and manufacture thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02558U (en) * | 1988-06-10 | 1990-01-05 |
-
1979
- 1979-10-03 JP JP12779379A patent/JPS5651726A/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56138726A (en) * | 1980-03-31 | 1981-10-29 | Olympus Optical Co Ltd | Photometric apparatus |
| JPS626214B2 (en) * | 1980-03-31 | 1987-02-09 | Olympus Optical Co | |
| JPS5828827U (en) * | 1981-08-18 | 1983-02-24 | オリンパス光学工業株式会社 | Camera reflection photometry device |
| JPS58189619A (en) * | 1982-04-02 | 1983-11-05 | イ−ストマン コダック カンパニ− | Photographic camera and manufacture thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6138454B2 (en) | 1986-08-29 |
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