Optimizing Photographic Detection at Large Telescopes

Abstract

Photographic detection of faint astronomical objects is divided into two categories: Class I, high signal-to-noise ratio; and Class II, low signal-to-noise ratio. The differing techniques for optimizing detection in the two classes arc described The characteristics of finer grained, high γ plates and their especial utility in photographic astronomy are discussed. Recent pro-cedures in gaseous hypersensitization effectively eliminate low intensity reciprocity law failure at the telescope. The best plates so treated provide large area detectors operating at a Detective Quantum Efficiency of about 4 percent.