[jambutty]

Originally Posted by Studio25

A CRT screen works on the basis of a line of electrons that scan down the screen. The bright band you see on digital images (on both stills cameras and video cameras) is the bit of the screen that is scanned while the shutter is open. The rest of the screen, if visible, is just the glowing remains of previously scanned phosphor.

If the band moves, it's just the result of a different in the time you take the picture. You'd expect it with stills, but with video, it's indicative of a TV and video camera that are not working exactly in synch.

An LCD screen will flicker as a whole, not in bands. It does have a screen refresh rate, like the CRT screen, but the whole screen refreshes simultaneously. The brightness if the image will be dependent on where the image is taken between one screen refresh and the next.

Although you weren’t to know, I am aware of how a CRT TV works, at least the old style. Technology has moved on since my day.

But thanks anyway, the picture is much clearer now. Er! Pun intended, I think!