"w4jle" W4JLE(remove this to wrote in
:

Refresh rate. Your used to seeing a 60 Hz refresh rate (actually two
alternating frames at 30 Hz) on your home TV.

If you go to Europe, you go nuts for the first few days getting used
to the flicker as they use a 50Hz refresh rate.

What a half correct and half junk science answer!

Yes here in the UK we have a refresh rate of 50Hz on our PAL standard
sets compared to 60Hz on NTSC standard TVs but I can't think why it would
drive you nuts? If that's the case, you should be going mad constantly
when looking at PC monitors, EPOS displays and ATM machines as most have
different refresh rates from 47Hz upwards!

The reason is correct as at the top - refresh rate or more a sync problem
- when a computer monitor is 'filmed' but the camera used is not
'synced' to monitor's refresh rate, you see the monitor at one rate being
filmed at another - hence a mismatch.

Really the camera operator should lock the scan rate of the camera to the
refresh rate of the monitor, then both are at the same rate and you get a
steady image with no flicker!

Simple as that and now pretty much a feature on most professional video
cameras.

Brian.