LOW LIGHT LEVEL PHOTOGRAPHY.
Technical rept., Mar-Oct 65,
ARMY ENGINEER GEODESY INTELLIGENCE AND MAPPING RESEARCH AND DEVELOPMENT AGENCY FORT BELVOIR VA
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This report presents an analysis of passive, low light level photographic systems using topographic cameras. This analysis was performed to evaluate the applicability of low light level photography to topographic mapping. A theoretical expression for the illumination threshold of a photographic system capable of producing photographs acceptable for map compilation at 150,000 and with 100-foot contours was derived. The theoretical expression was in fairly close agreement with an empirical formula developed at the Air Force Avionics Laboratory, Wright-Patterson Air Force Base, Ohio. The present technology-limited illumination threshold was calculated. Report concludes a Present-day technology would permit the design and development of a twilight photographic system capable of taking photographs 30 minutes after sunset or before sunrise, b a practical moonlight photographic system would require that the present technology-limited illumination threshold be reduced by a factor of 40, and c a new film-developing process now under test may lower the illumination threshold by a factor of 10. Author
- Cartography and Aerial Photography