richard@gryphon.CTS.COM (Richard Sexton) (10/20/87)
In article <2538@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes: >In article <1950@gryphon.CTS.COM> Richard Sexton writes: >> >> [...] The Green phosphor has a shorter persistence than >> either the Red or Blue. > >Sorry, typically green has the longest persistance of the color phosphor >triads. Hmm. Does it make any difference if I say I have a Sony, not a Commodore monitor ? When I draw single pixel horizontal lines in red (15, 0, 0), green (etc) and blue (etc), the green flickers the most. The blue flickers the least. Does this mean my monitor is not 'typical' :-) >George Robbins -- Richard J. Sexton INTERNET: richard@gryphon.CTS.COM UUCP: {hplabs!hp-sdd, sdcsvax, ihnp4, nosc}!crash!gryphon!richard "It's too dark to put the keys in my ignition..."
tomb@hplsla.HP.COM (Tom Bruhns) (10/22/87)
>In article <2538@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes: >>In article <1950@gryphon.CTS.COM> Richard Sexton writes: >>> >>> [...] The Green phosphor has a shorter persistence than >>> either the Red or Blue. >> >>Sorry, typically green has the longest persistance of the color phosphor >>triads. > >Hmm. Does it make any difference if I say I have a Sony, not a Commodore >monitor ? When I draw single pixel horizontal lines in red (15, 0, 0), >green (etc) and blue (etc), the green flickers the most. The blue >flickers the least. > >Does this mean my monitor is not 'typical' :-) > >>George Robbins > >-- >Richard J. Sexton It seems to me that if you want to measure PERSISTANCE, you should use a (high speed) photocell, connected to an oscilloscope. If you want to measure the psychologically/physiologically perceived FLICKER, you should run experiments as you have described. I was under the impression that the rgb phosphors of color tv's/monitors all have persistance short compared with 1/30 second frame rate of interlaced amiga displays (except of course for the expensive long-persistance monitors). Now I'm curious -- maybe I'll measure my Sony and my 1080 for persistance for r, g, and b. Does anyone know if there is a reason other than low volume production that the long persistance monitors are expensive? And what are people's favorite color and font combinations for best performance with interlaced text display? Under what lighting conditions? I recall reading some of the proposal that RCA and NBC made to the FCC for the current USA color broadcast standard back in 1953. They had done quite a bunch of studies to support the 60Hz field/30Hz frame rate, but of course, those studies were for continuous color/gray scale pictures, not digitally generated text! A number of their observations revolved around how we perceive color and flicker; this was given higher billing, as I recall, than the technical aspects of persistance of various phosphors. Tom Bruhns uucp: !hplabs!hplsla!tomb