At a time when recent advances have produced a dramatic increase in the detection efficiency of astronomical instrumentation (e.g. with the advent of charge coupled detectors and single photon counting systems), it would seem appropriate to review the progress which has been made. To this end, IAU Colloquium No. 67 was recently held in Zelenchuk, U.S.S.R. Topics discussed included spatial and spectral interferometry, conventional and new designs for spectrographs, image intensifiers and solid

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... ate detectors, large telescopes, and the efficient matching of telescope images and instrumentation. The spectral region considered included the infrared as well as the visible.