A note on luminance calibration of raster-scan cathode-ray tubes: temporal resolution, ripple, and accuracy.
Accurate luminance calibration is an important issue for stimuli in vision research. Raster-scan cathode-ray tubes present a rapidly scanning spot with a luminance of the order of 10,000 cd m-2 (the actual value depends on video timing and phosphor persistence). With little spatial integration this may result in overloading of the front stage of a photometer. More importantly, even if averaged over hundreds of milliseconds, the pulsed nature of the luminance signal will markedly reduce accuracy of the luminance measurement. A frame-synchronised photometer is described to increase measurement accuracy whilst still rapidly acquiring the result.
Bach
M
M
Univ.-Augenklinik, Killianstr, Freiburg, Germany. bach@uni-freiburg.de
D016288:Computer Terminals; D015350:Contrast Sensitivity; D003626:Data Display; D006801:Humans; D010783:Photometry / Q000295:instrumentation; D011601:Psychophysics; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation