Xref: utzoo sci.electronics:3977 rec.audio:8534 comp.graphics:3283
Newsgroups: sci.electronics,rec.audio,comp.graphics
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Perceptual Color (was: Re: Looking for Blue LEDs)
Message-ID: <1988Oct4.162222.15634@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1138@nmtsun.nmt.edu> <862@ritcv.UUCP> <255@rna.UUCP> <4422@lynx.UUCP> <871@ritcv.UUCP> <870@dlhpedg.co.uk> <6101@watcgl.waterloo.edu> <790@ncar.ucar.edu>
Date: Tue, 4 Oct 88 16:22:22 GMT

In article <790@ncar.ucar.edu> cook@stout.UCAR.EDU (Forrest Cook) writes:
>>a flashing b/w light can take on the appearance of color.
>
>So, if you take a fast response white light source and modulate its duty
>cycle and frequency, will you fake the eyes into seeing colors?

It helps if you can modulate not only the duty cycle but the repetition
pattern, since my recollection of this stuff is that simple periodic
flashes are not quite right for the job.  But yes, you can fake colors
this way.  It's not spectacular, and I think it doesn't work on everyone,
but it does work.  Last I heard, it's not clear exactly why.
-- 
The meek can have the Earth;    |    Henry Spencer at U of Toronto Zoology
the rest of us have other plans.|uunet!attcan!utzoo!henry henry@zoo.toronto.edu