One of my many 'hats' in FTC in the 50's was Aircraft Recognition Instructor at M-S-G where we used the epidiascope to flash pictures on the screen, and one day I said that we'd try a 'quick flash', possibly 5th of a second. 'No chance' was the reply. The students were used to aircraft of the day, some gleaned from the JSRJ, but the first one up was a picture of a half-naked starlet. No problem in recognition there, which proved a point. Know your subject.