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From: tugs@utcsrgv.UUCP (Stephen Hull)
Newsgroups: net.cog-eng
Subject: Re: start off with a bang -- screen colors question...
Message-ID: <1992@utcsrgv.UUCP>
Date: Thu, 18-Aug-83 12:18:22 EDT
Article-I.D.: utcsrgv.1992
Posted: Thu Aug 18 12:18:22 1983
Date-Received: Tue, 23-Aug-83 15:52:12 EDT
References: <3659@sdcsvax.UUCP>, <1990@utcsrgv.UUCP>
Organization: CSRG, University of Toronto
Lines: 34

WRT the question of qhether to go with a very bright display in a bright
office, thus being able to see pen and paper, or to get a darker display
in a dimly lit office and be stuck with only using the CRT:
Perhaps the best solution is a dimly-lit CRT which has a built-in Luxo desk
lamp...

But seriously, folks, I worked on a PERQ with the supposedly 'normal' black
on white display, and heartily do NOT recommend its use. It looks nice, sure,
but after a couple of hours both I and everyone else who used it complained
of eye strain or headaches or fatigue.  The problem seems to be twofold:
first, the black on white seems (I'm not trying to support this scientifically,
this is just a subjective opinion) to emphasize lack of sharpness of the
characters -- the text always seemed fuzzy, yet I'm sure it was no worse than
a standard white on black terminal. Second, when 95% of the screen is lit,
whatever minimal, only-detectable-by-peripheral-vision flicker is present
really gets to you after a while.
Something which had some impact -- possibly real and possibly psychological --
was the radiation business. By ballpark figures, a black on white screen
puts out 20 times the EM radiation a white on black does.
As for the "naturalness" of black on white, while this is a conventional
colouring system for the printed word, and thus may have some advantage
from a familiarity point of view, it's certainly not anything we have a
physiological preference for. Have any studies been done to compare
resolvability (not resolution) of B on W versus W on B?
And finally, black on white CRTs are NOT the same as hardcopy for the simple
reason that paper doesn't give off light. Mind you, it REFLECTS light...
hmmm, that could be equivalent, couldn't it? Or could it? Ah, well, just
another question to be answered from the Wonderful World of Ergonomics...
    steve hull
-- 
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