On Sat, 03 Jan 2004 20:09:14 GMT, Mike Coslo
wrote:

Cecil Moore wrote:

hnmm wrote:
Human eyes can detect the refresh rate flicker up to a certain
frequency. My peripheral vision can detect the 120 Hz flicker
of florescent lights as well as flicker in computer monitors.
Drives me crazy.

The scan rate of most computer monitors is closely related to multiples
of the scan rate of a NTSC television signal scan rate. This leads to a
signal that is often twice the rate of NTSC scan. But since the monitors
are not synchronized, the computer monitor will show lighter and darker
areas depending on it's scan rate. Computer monitors will vary in their
"look" on television, from a whole screen flicker to a darker colored
bar that works it's way down the screen. This is all due to the scan
rate frequencies.

Yes, the exception would be if the monitors and the TV camera are
synchronized, as might be done with the news set.

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom