How come when a TV News camera takes a shot of a PC monitor, the monitor has those horizontal lines?
Font size:
Question by UberStein: How come when a TV News camera takes a shot of a PC monitor, the monitor has those horizontal lines?
Have you ever seen this on the local news? It’s like the monitor doesn’t want to be on camera 
Best answer:
Answer by Gravy B
LOL its a natural phenomina
the camera scans from left to right, top to bottom the tv displays the same way so the camera sees an almost stop motion kind of thing
Add your own answer in the comments!
Tags: Camera, come, horizontal, lines, monitor, News, shot, takes, those
Add to:
del.icio.us |
Digg
del.icio.us |
Digg
Home
Set as homepage
Add to favorites
Rss
One Comment
Because a PC monitor does not show a static image – it is being re-drawn every 1/60th or 1/75th of a second (whatever the frequency of the monitor display is).
When you look at one in real-life, the image looks stable because your eye retains an image for 1/24th of a second, so sees a complete image (the brain making sure it synchronises to the complete image, rather than a half-drawn one).
A TV camera records images every 1/25th or 1/50th of a second (depending on the camera type), but does not synchronise to a complete image like your eyes do. So it often grabs an image partly drawn; then the next 1/50th of a second, another slightly different partly drawn image. The difference in the frequencies between the camera capture and the monitor display determine how quickly the ‘bands’ move down the monitor.
You see the same effect when the TV shows a TV screen. You can use very high-frequency monitors to compensate for the effect.
Post your comment