LIGHT BUDGETS, LIGHT AND HEAVY LOSSES - ONE-SIDED OR 2-SIDED TANDEM SCANNING (REAL-TIME, DIRECT-VIEW, CONFOCAL) MICROSCOPY

A practical arrangement was constructed which permitted the demonstration of the equivalence of the autocollimation variant of the rotating-aperture-disc, real-time, direct-view, confocal microscope (the one-sided tandem scanning microscope - 1sTSM) and the original, centrally symmetric, two-sided TSM (2sTSM). It permitted the direct examination and disproof of claims that 1sTSM has an advantageous 'light budget". It is shown that more efficient use of available light is made in 2sTSM and that contrast may be further improved by the (future) more efficient rejection of waste light.