Need To Know on Overscanning

[Herry Dunston]

I've heard of things about Overscanning, the which could explain about a few things about the picture quality of TVs no matter what kind. I was watching two different DVDs with two different ratios (1.78 and 1.85), and quite honestly, I couldn't tell the difference. It was only when I look at very top and bottom of my Sharp Aquos that I caught a GLIMPSE of the black bars on a 1.85 screen. I also compared the picture of the same DVD in the TV and in the computer, and I noticed that the computer suspiciously has more picture on the sides than on the TV. I find it annoying that my TV (or the dvd player, possibly) croppes the picture size for the screen.

Does the term "overscan" relates to the cropping in widescreen DVD movies on TV?

[Ratman]

I guess you could equate it to 'cropping' in a sense.

Here's some info:
http://en.wikipedia.org/wiki/Overscan
http://en.wikipedia.org/wiki/Overscan_amounts
http://www.cnet.com/4520-7874_1-5107912-16.html

[Herry Dunston]

I already checked the wiki sites with little understanding, but the cnet link gave me a good idea of how overscanning works.

Are there such HDTVs that have 0% overscan?

[d6500k]

Look for digital displays that either on their own, or with the use of an additional scaler, can produce 1 to 1 pixel mapping. Used to be that NASA bucks were required, down to county gov't. expenditures now.

I have not calibrated an "aquos" to date, but if I can gather any pertinent data that might help, I'll post it for you.

Doug k

[57U]

There are sometimes issues that arise when TVs have low overscan (less than 2%). Most TVs that I've set up recently (newer ones) have about 2-4% overscan all around. Older TVs had more, usually 5-6% and some CRT-based Direct View TVs going as high as 10%.

The issue that can arise is a white line at the top of the screen, which contains the VBI information (used for CC, etc). Some affiliates do not properly send out signals, especially on upconverted 4:3 channels and you will see this white line if your overscan is too low.

I suggest you check the overscan using a setup DVD, as discussed in the HDTV FAQ "What you need to do to your new HDTV" and realize that 2-4% overscan is perfectly normal.

[Herry Dunston]

If overscanning in TVs of various kind are regularly standard, then I feel disappointed about the process. I can understand about the white line thing on regular broadcast stations, but if I'm watching a DVD, TVs should have the option of adjusting the cropping of the picture.

[57U]

With people wanting the least expensive HDTVs possible, this is simply not a feature that is important to most people, since it would add some cost.

If it is important, they can go the HTPC route.

Many people purchase and watch Pan&Scan movies where they miss as much as 50% of the movie (if it was 2.35:1 aspect)

[Herry Dunston]

Well, I definitely misused the word, cropping. The TVs didn't exactly remove the little edges from the picture, but they did hide a good amount of picture data.

What can you users say about DVD players with incremental zoom?

(source: http://www.mastersofcinema.org/reviews/03lookingbeyond.htm )