Why do computer screens look all weird on video cameras?

hmm...

I'm not sure about LCD flat panels, but CRTs work by having an electron beam scan back and forth across the screen as it sweeps down, firing it with lesser or greater intensity to make the phosphors on the screen glow brighter or dimmer on each pass. As the beam leaves the phosphors fade.

Each frame in a video represents a short segment of time during which the camera gathers light to creat the image. The bright and dark bands you see on videotaped computer screens (and TVs) are the result of the camera and the display's electron gun scanning being out of sync. Some parts will be scanned more than others during the frame's time segment.

When studios film movies they can use special electronics that syncronize the monitors & televisions with the cameras so that they can have the displays appear normal. because its high resoultion --video cameras. and there are tiny visual things like horizonatl lines only other technology can see.

Im a girl that knows this from expierence ;) When you are filming a computer screen the camera has 2 make x2 as much pixels I think if you tape an LCD screen you will find this to not happen. Johnny Secret is on the right track. Your camcorder shoots at 30 frames per second. CRT's - computer monitors, TV's etc., operate at a different frequency. The horizontal banding is caused by the difference between the 2 frequencies. Also the cleanness of the electrical source can make a differnce. Electricity from the "grid" often varies in voltage and is referred to as "dirty" power. "Dirty" power will effect the cycle time of the horizontal banding also.

Professional productions have learned to eliminate this problem by adjusting the shooting speed to synchronize with the CRT.