Photographic Recordings with Enhanced Contrast Using the Storage Image Amplifier, and Applications in Research

摘要

When photographing low-contrast scenes with uneven background, films can be processed for optimum contrast only at 1 selected brightness and considerable information in other brightness levels is lost. Taking several pictures of the same scene and optimizing the contrast at different levels, does not solve the problem due to the nonlinear film response. Exposures taken at the toe of the H and D curve would not result in usable densities or, if taken at the straightline portion, the contrast rendition is not sufficient and the problem cannot be solved with film alone. A solution is the application of the storage image amplifier in which scenes, once stored, may be subsequently reproduced several times on the phosphor screen with different brightness and contrast rendition by changing electrode voltages. Assuming for film transport 0.15 sec per frame, each scene yields 10 pictures, with new scenes every 2 sec. A recently developed simultaneous storage image amplifier shows contrast rendition achieved so far only with the sequential image amplifier. Further, the storage screen acts as limiter preventing halation caused by strong point sources occurring in conventional devices. Applications in physics research and typical photographs with different contrast rendition are shown. (Author)