Method and apparatus for controlling exposure by selective use of blocking visible filter
US4474441A · kind A · utility
3Cited by
48References
47Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 4, 1980 |
| Grant date | Oct 2, 1984 |
| Priority date | — |
| Expiry date | Nov 4, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/087
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Method and apparatus for automatically controlling exposure of a photographic film by evaluating non-visible spectral scene light frequencies. Particularly for artificially lit scenes, an evaluation of predominantly infrared frequencies is preferred. In one embodiment, the IR scene lighting is evaluated under control of the shutter aperture system while in another embodiment, the strobe itself is controlled by its own photodetector responsive to IR scene light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.