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From: tomb@hplsla.HP.COM (Tom Bruhns)
Newsgroups: comp.sys.amiga
Subject: Re: Another A2000 Question (LP monitor smear?)
Message-ID: <5160003@hplsla.HP.COM>
Date: Mon, 26-Oct-87 16:29:56 EST
Article-I.D.: hplsla.5160003
Posted: Mon Oct 26 16:29:56 1987
Date-Received: Thu, 5-Nov-87 00:09:37 EST
References: <177@tahoma.ARPA>
Organization: HP Lake Stevens, WA
Lines: 24

Writes  / richard@gryphon.CTS.COM (Richard Sexton) /:
> 
> I'm certainly not an expert on this subject, but I just can't see how
> 'eye persistence' has any bearing on the matter. Its the "now I'm
> here", "now I'm not" attribute of an interlaced display that causes
> the flicker, not the physiological response of the eye to color.

If you have any doubts that there is indeed a physiological/psychological
aspect to all this, try viewing exactly the same display (interlaced)
with low and moderate ambient lighting and low and moderate monitor
intensity to match.  MOST people (:-) perceive the low light/low
intensity situation as having much less flicker.  I know for a fact this
works on standard B/W TV's, as well as on color monitors, and the
B/W phosphor has a time constant of not-very-many microseconds (which
allows light pens and flying spot scanners to work).  I still wanna
measure my monitors' phosphors' persistances, but haven't found time
yet.  Will post when I do.

(The above experiment can also be done with a single LED, driven by a
short pulse every 1/30 second or so -- same results, I believe -- and the
LED turns off pronto when you turn off the drive current.)

Tom Bruhns
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