Quote:
Originally Posted by Zeb
Hey I just thought...
Is there anything stopping you from using CRT and LCD?  |
Yes. In most cases, you can output to two diferent screens no worries, but a lot of video cards are unable to output at two different frequencies at the same time. This means you have to run your CRT at 60hz, which looks
terrible! (Your particular video card may be different, but it is essential to check this before you buy.)
Quote:
Originally Posted by Zeb
I'm suggesting this because LCD monitors are "eye friendly" as they don't cycle the display like CRT monitors do. Many offices and other such work places move to LCD because very few people get headaches while using them like they do with CRT monitors. PAL systems run at 60Hz which also happens to be the same frequency of the human body - the two clash.
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Nope. Not even close. PAL is TV, nothing to do with monitors. Same with NTSC: TV technology, and very old TV technology at that.
CRT computer monitors - pretty much anything made since IBM introduced the first VGA screen in 1987 - can run at any of a wide range of frequencies. A properly adjusted monitor runs at 85hz or better. The rule-of-thumb is to adjust your refresh frequency up until it looks good, then go up a bit more till it starts getting fuzzy or weak, then go back a step or two.
You need about 85hz on a CRT to avoid flicker. In most cases, there is little or no point in going beyond that - it just stresses the electronics harder for no tangible benefit. CRT screens, remember, actually only have
one pixel lit at any single instant. The illusion of a well-lit, even screen is created by a combination of phosphor latency (the glowing dot takes a while to fade) and the human eye (past 85hz or so we can't see the flicker, so it effectively ceases to exist, so far as humans are concerned).
Running a CRT at 60hz produces a very stressful, flickery picture. Many (most?) video cards default to 60hz or 72hz or even an eye-destroying 50hz because these very slow refresh frequencies are the only ones certain to work on any monitor, even a very old, cheap one. But all modern video cards (since about 1985) allow you to adjust the refresh rate, and that is the first thing you should do after you pug a monitor in and adjust the display resolution.
TFT screens work a completely different way. Essentially, each dot on a TFT screen is switched to a particular brightness level and then stays there until further notice: it doesn't pulse the way dots on a CRT do. No flicker. So refresh frequency for TFT screens is a non-issue. Most default to 60hz, which is fine. But they could be 160hz and wouldn't look any different, or 0.6hz and the only difference would be very slow screen redraws.