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Thread ID: 79902 2007-06-05 07:00:00 Fit to the screen katharinem (3459) Press F1
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556356 2007-06-06 16:13:00 Well if I change the refresh rate of any CRT, I always have to adjust the picture as it will always change size or move


perzacktly
drcspy (146)
556357 2007-06-06 21:05:00 For CRT's under fluorescent lighting avoid refresh rates that are a mulitple of 50Hz as the two frequencies interact, so 72Hz can be better than 75 ( 1.5 times 50 )
Single fluorescents run at 100Hz (conducting on alternate half cycles) but can give flicker effects when the tube is very old. Dual tube units are phased to operate on alternate half cycles, still at 100Hz but subjectively reducing flicker even further.

Apart from that, I have been dealing with CRT interference and flicker problems professionally for over 10 years and I have only once ever seen an effect that was directly attributable to a fluorescent light, and that was simply a dying tube.

Most flicker (or shimmer or shake) is caused by external electromagnetic fields from internal power wiring, external overhead or underground power lines, powerpacks stuffed behind the monitor, or two monitors side by side operating at different refrsh rates.

To check for flicker, use your peripheral vision which is much more sensitive to movement.

LCDs don't have a refresh rate in the same way that CRTs do because they are not scanned, and their backlights operate at high frequency so interaction with lighting would be very unusual.

Cheers

Billy 8-{)
Billy T (70)
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