An earlier investigation of the senior author suggested very strongly that various quite different PCF’s (pulse-to-cycle fractions) were, under some conditions, equivalent in producing CFF. This was contrary to common expectation, and was not fully confirmed by the scant amount of data then obtained. The present study consisted of testing the earlier suggestions by the use of seven observers using one method, and two observers using a second method of collecting data. The CFF’s for each of the following PCF’s, 1/30, 1/8, 1/4, 1/2, 3/4, 7/8, and 29/30, were obtained as the photic intensity was varied. In Part I, the range was from 1.28 c/ft2 to 1164 c/ft2. In Part II, the range was from 0.014 c/ft2 to 1400 c/ft2. The data produced families of curves, one curve for each PCF. Some pairs of these curves crossed each other, the points of crossing indicating that, under those conditions, two PCF’s were equivalent.
© 1960 Optical Society of AmericaFull Article | PDF Article
OSA Recommended Articles
S. Howard Bartley and Thomas M. Nelson
J. Opt. Soc. Am. 51(1) 41-45 (1961)
V. V. Lloyd and C. Landis
J. Opt. Soc. Am. 50(4) 332-336 (1960)
J. Opt. Soc. Am. 50(4) 328-331 (1960)