AAVSO: American Association of Variable Star Observers
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Adapting a 10-Inch Astrograph for Sheet Film

Volume 20 number 2 (1991)

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David B. Williams
9270-A Racquetball Way, Indianapolis, IN 46260

Abstract

The Link Observatory 10-inch photographic refractor is designed to use 8x10 inch glass plates. Inexpensive sheet film can be used by holding the film flat behind a sheet of clear glass in the plateholder. Experiments with panchromatic film and yellow or red filters were not very satisfactory, due to the blue-corrected objective's steep focal gradient at longer wavelengths. However, blue-sensitive Kodak SB-5 X-ray film produces excellent images.