A Tachistoscope for Exposing Large Areas

A simple tachistoscope for student labs

“…The shutters mentioned above have been used for a number of years without any appreciable wear. The apparatus is superior to those using a "guillotine" door (Bugelski, 1951), the sectored rotating disk (Ferree & Rand, 1937), and the dual mirror arrangement (Evans, 1931) because of its simple, compact desigi and because both duration of exposure and intensity 0 illumination can be varied systematically. Users must, however take note that leaf shutters such as this are not reliable enougl for research, since exposures at a given setting vary by as much a: I<Y%.…”