Method and apparatus for measuring characteristics of photographic negatives
US4821073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1987 |
| Grant date | Apr 11, 1989 |
| Priority date | — |
| Expiry date | Nov 19, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/735
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is provided for determining the exposure of a photographic negative to be printed in a cropped, enlarged format. The method is performed by defining a region of the negative to be printed, measuring selected density characteristics of the negative in only that region, and determining the exposure based on those measured density characteristics. The method is implemented in an enlarging photographic printer including means for defining the region of the negative to be printed, and means for measuring the selected density characteristics of the negative only in that region. Means are provided for using the selected density characteristics to calculate an exposure for the negative region, and for exposing the negative region onto photographic paper in accordance with the calculated exposure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.