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From: breuel@h-sc1.UUCP (thomas breuel)
Newsgroups: net.micro.amiga
Subject: Re: Technically speaking.. Flicker
Message-ID: <898@h-sc1.UUCP>
Date: Thu, 30-Jan-86 06:58:25 EST
Article-I.D.: h-sc1.898
Posted: Thu Jan 30 06:58:25 1986
Date-Received: Sat, 1-Feb-86 04:37:01 EST
Organization: Harvard Univ. Science Center
Lines: 31

> The basic flicker is not really the fault of the amiga, it is caused by the
> relatively short persistance of the color phosphors.  Monochrome phosphors
> are available in varying persistences - from very long like used on medical
> heartbeat displays to very short for oscilloscope photography.

No, using high-persistence monitors is not a solution. When you
scroll text or move your mouse-pointer around, it looks terrible
on a high-persistence monitor (just look at the IBM screen).
To make this perfectly clear: the reason why 70Hz interlaced monitors
do not appear to flicker is NOT that the persistence of the monitor
is matched with the refresh-rate, it is that the human eye/brain
cannot perceive flicker above 30Hz.

The way to get good high-resolution displays is not to use high-persistence
monitors, it is to use higher frequency displays. The LISA, the Mac, and
the Atari ST show that this is possible economically, at least for
black and white displays. Call me spoiled or whatever, but I have
gotten very used to my 700x500, flicker-free, low-persistence LISA
screen, and I'll not switch to a computer that doesn't have a similar
display quality.

Now, again, the reason why I am posting this is not to annoy Amiga owners
or to encourage the purchase of Atari ST's, but simply the hope that
Commodore will add a 640x400 70Hz mode to their otherwise great machine
if there is suficient demand for it. I just can't see how people can
reasonably argue that using a computer in a dimmed room, sitting back
3 feet, using a high-persistence monitor, or drawing pixels on top
of one another can be more than a bad compromise, given that a real flicker
free high-resolution display is not all that hard or expensive to make.

						Thomas.