Accession Number:
AD0647715
Title:
AERIAL PHOTOGRAPHY USING WIDE-ANGLE OBJECTIVES WITH SHADED FILTERS,
Descriptive Note:
Corporate Author:
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
Personal Author(s):
Report Date:
1966-12-12
Pagination or Media Count:
11.0
Abstract:
The article gives a description of illumination equalizers prepared by the use of thin semitransparent metal films on filter lenses placed in a vacuum. Before 1941 these neutral filters were directly applied to the objective lenses, but it was discovered that this can be harmful to the optical properties of the latter. Nickel finds general use because of its excellent mechanical resistance to wear and the firmness of the metal-glass bond. Although the uniformity of the light distribution over the focal plane of wide angle lenses is vastly improved, the negative must still be subjected to a contrast developer. A typical formulation is given. Author
Descriptors:
Subject Categories:
- Cartography and Aerial Photography
- Geodesy