I used to consider myself a critical viewer. That all changed.
I bought AVIA and calibrated my panasonic rptv (47WX49) and boy was I pissed.
I have 7% overscan on the top and right and 5% on the bottom and left.
My image is tilted and to top it off, when I did the picture test for blooming and the sharpness test, there was no difference between 0 and the highest setting.
What exactly is overscan and what does it affect? Regular HD/SD signals? Everything the set outputs? I mean, I know what it is (bleeding off the edges per se) but wasn't sure if it was just for maybe PCs or something like that.
Yes, overscan is normal. That's why you can't see the black bars to the top/bottom of 1.85:1 DVDs with overscan. It hides stuff on the edges of the screen that you don't want to see (annoying green lines on certain TV broadcasts, etc.).
You might be able to re-center the picture through your set's Service Menu, but overscan is another story.
If you use an HTPC to watch DVDs, you have more options with resolutions, etc. to get rid of overscan.
And as far as blooming goes, I know some TVs won't have blooming no matter what (like my DLP). But I would assume a CRT would show it...
And you might not notice a difference between the sharpness settings, unless you switch betwee a high and low value instantly, rather than by notching it up/down manually. If you switch between say 0 and 60, you'll probably notice a difference if you have the right material on-screen.
And rather than the blooming test - if you don't see blooming at all - check the greyscale patterns so you can make sure your blacks and whites are black and white, and all the 5% steps in between are even and noticeable - ie., you should be able to see a difference between 0% (black), 5%, and 10% at the bottom, and 100% (white), 95%, and 90% - with even steps in-between.
Yup, when you really get into your TV, you might find that it's not as perfect as you thought.
You will see all kinds of flaws unless you get your TV professionally calibrated and tweaked. Excessive overscan, uncentered image, unoptimized greyscale, etc. are normal.
(I will say my Sony KP-57WS520 was in really good shape out of the box. I think my overscan was around 5%, but the picture was a bit off-centered. My greyscale was very good too. We were able to get it better and now my overscan is around 4% and the picture is better centered.)
Many modern crt sets, both direct view and rptv will not show the "blooming" described on the AVIA disc. This does not mean it's safe to crank contrast up all the way.
Basically when using the white level pattern turn contrast down until the top box turns noticeabley gray, then back up until it just turns true white again. If you need to go higher to overcome ambient light do so but on a crt rptv it's safest not to go over 40-50%. At that point you need to look at room light control rather than cranking up the white level any more.
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