Office of Aerospace Medicine Technical Reports

FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute


Report No: DOT/FAA/AM-70/15

Title and Subtitle: Two-flash thresholds as a function of comparison stimulus duration

Report Date: September 1970

Authors: Lewis MF, Mertens HW

Abstract: The proposal that two-flash thresholds may be used as direct measures of the critical duration (tc) of Bloch's law was tested. Two-flash threshold was found to be an increasing function of comparison stimulus duration for durations of 3 to 22 msec. indicating that two-flash threshold does not measure tc. Increasing luminance in the range of 1.0 to 3.0 log mL. enhanced the effect. Application of these data to specifications for strobe lights used as anticollision devices is discussed.

Key Words: Strobe lights, Collision avoidance, Luminance, Vision, Visual perception

No. of Pages: 7

Last updated: Friday, June 1, 2012