Clipping occurs when watched on TV

P

perera.amila

Member
I recently did a video for dvd. The project was handled as a NTSC 4:3 one. The footage was also NTSC from a Sony Hi8.
After doing everything I rendered and everything went quite well. When I playedback on the computer it looked great.
But when I watched the dvd on the TV(NTSC) there was an obvious clipping from the four edges.
After, I did the same project limiting my video to the Action Safe Area. But then when I played back the DVD on TV there is a gap i.e. the video frame was too small for the TV.

How can I avoid this problem?
Is there a standard scale to which I should zoom out/in the video to have the best display on the TV.
This problem further gets intensed when creating a photo montage.
ThanX in Advance..
 
That's not a "problem", per se. That's the way televisions work. It's called "overscan"--about 15% of the image scanned by a camera's sensors and then displayed on a CRT monitor will usually not be seen. This is due to a holdover of the old crummy analog broadcasting standard that is NTSC--I can't quite remember all the technical specifics of it (college was oh-so-long-ago). Here's a Wikipedia entry about overscan.

Your intent of shrinking the video down to view the "whole picture" is understandable, but you'll end up creating more issues for yourself, like the gap that you're seeing. It would be even worse if you viewed the DVD on an LCD TV or computer monitor at full-screen, as those devices don't use overscan--you really do see the whole picture. So if you shrunk your image down, you'd see really wide black bars around the image.

Most professional cameras have an overlay in the viewfinder or LCD screen that will show action safe. One would use those marks to properly frame a shot, and keep the most important elements viewable on the widest range of devices. This is likely an issue that will decrease (but not totally disappear) as displays are replaced with fixed-pixel devices, like computer monitors and LCD/plasma TVs.

So the best solution is to frame your shots properly, and for a photo montage, position your photos so that everything you want to see is maintained within the action safe area. Not the answer you want to hear, I'm sure, but it's the way we all work with this crazy video stuff :)

Good luck!
 
Thank you my friend.
Though it is not the answer I expected for now I got a real, vivid explanation as why I face the problem and what would be the results if I try to avoid it.
(Overscan - really something I did not knew)
Thank you!!
 
The reason overscan is an NTSC standard is because older televisions used to shrink the image over time and consumers would be left with a black frame around their picture. In an attempt to not piss people who owned televisions off, it was decided to do this overscan. I don't understand why overscan exists today however, since televisions don't have this problem anymore.
 
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