TV safe area

8bitwizard · Post by **8bitwizard** » Mon Sep 10, 2007 2:52 am

The main reason is that TV manufacturers are cheap, and manufacturing variations will make it too hard to align sets for perfect centering. But there is a subtle reason which is not obvious until you have the ability to center your picture horizontally. If you do that and rotate the TV 90 degrees, the earth's magnetic field will be strong enough to change the centering.

So rather than have idiots whine about blank edges on their TV sets (the same morons who now buy "full screen" DVDs and play them in stretch mode on their 16:9 plasma TV sets), the manufacturers simply defined a 5% overscan area. And if the alignment is off vertically, everybody will be annoyed by the closed captioning and other digital data just above the picture area.

I still think it's stupid for LCD/plasma TVs which don't have the alignment problems of CRT sets.

evildragon · Post by **evildragon** » Mon Sep 10, 2007 3:32 am

Most new LCD and Plasma TVs allow you to change the overscan. Mine does, but I noticed that when it's on 0%, there usually is some black either on the right, left, bottom, or top. It's like the TV station itself has bad centering, and these were digital channels. (The HD channels didn't have this issue however)

TulioAdriano · Post by **TulioAdriano** » Mon Sep 10, 2007 3:18 pm

As Shiru mentioned there is the so called "TV SAFE AREA" most of the CRT TVs will have issues displaying information on the edges of the pictures. We had to work on redesign of TRPG's menues because of that. Because it was mainly tested on emulators, the first letters of the menu commands were being cutted. We shifted right a little so that it can be safely displayed. Here's a diagram to example it on a 4:3 ration screen:

The safe area tend to be smaller on older TVs. Newer produced CRT TVs have been able to show more of the screen area, but still there are a lot of old tvs out there. I had a 1978, 1993, 1998 and 2006 CRT TVs back home in brazil. It is very clear that for the first two the display are are about the same (channel logos usually display exactly on the bottom right of the screen), the 1998 one would have some space after the logo. Those three were the old concave CRT. The newest one is a Flat screen CRT, that one display almost all the screen area but still cut some lines.

Here I have LCD tv, and it seems that it shows 100% of the screen area. I have played all my game consoles (from SMS to Wii) and it seems that it displayes everything.

I think for safety purposes skipping at least two rows and two columns (16 pixels) on MegaDrive for all you want to make sure that it appears on the screen would be safe. I had the 1993 TV in my bedroom and I clearly remember that it cutted the top part of the score points for Streets of Rage 1. That would make me mistake inputing my name after I finish the game on the high scores.

Most of the games took that into consideration so you can take a look on games that have on screen menues like Phantasy Star IV for reference of where they start puting the words (not the borders).

Seeya.
Tulio

TmEE co.(TM) · Post by **TmEE co.(TM)** » Mon Sep 10, 2007 4:10 pm

It is so weird... I clearly remember that an 198x year BLACK and WHITE Russian TV "Rekord" showed nearly all screen, same for a "horizont" that still works, and for my 1995 Philips... but one Beko downstairs and a Nokia in my brother's room don't show 8 pixels from left, but seem to display everything else...

Jorge Nuno · Post by **Jorge Nuno** » Mon Sep 10, 2007 4:30 pm

One thing I note on my cheapo CRT TVs is when the picture is bright, the cathode ray deflects more: the picture is larger and it's smaller when it's dark.

It is easy to prove this: Launch for example S&K in NTSC, start a level, when the red vertical bar appears with the level name hold start button: the game will pause with almost everything dark, and in the bottom you will see the "cram dots", when you unpause it it will be gone becuase the screen went larger...
(FBZ act 1 is very good to test this) and you need to run on a real MD/GEN

TmEE co.(TM) · Post by **TmEE co.(TM)** » Mon Sep 10, 2007 4:54 pm

That's true, the brighter the picture, the more "stretched" it gets... more high quality CRTs stretch much less.

Fonzie · Post by **Fonzie** » Mon Sep 10, 2007 5:47 pm

I think the megadrive already add left and right "dead" pixels... Except the 16pixel shift to the left, the whole screen should be seen on a normal PAL TV

And about the cheapo bright distorsion... yeah, I have this on my Ultra crap modern TV.. and "my" 15year old panasonic is just perfect...

TmEE co.(TM) · Post by **TmEE co.(TM)** » Tue Sep 11, 2007 5:41 am

The picture is blurry, but you can see overscan, and that is a PAL TV in NTSC !!!

Stef · Post by **Stef** » Tue Sep 11, 2007 4:47 pm

TmEE co.(TM) wrote:

The picture is blurry, but you can see overscan, and that is a PAL TV in NTSC !!!

neat !

8bitwizard · Post by **8bitwizard** » Wed Sep 12, 2007 3:58 am

evildragon wrote:Most new LCD and Plasma TVs allow you to change the overscan. Mine does, but I noticed that when it's on 0%, there usually is some black either on the right, left, bottom, or top. It's like the TV station itself has bad centering, and these were digital channels. (The HD channels didn't have this issue however)

Some LCDs (mostly for computers) aren't 16:9, they are 16:10 which is a little taller.

Also, I have a Commodore 1084S monitor which allows full vertical and horizontal size and positioning control. Want underscanned NTSC? No problem!

Chilly Willy · Post by **Chilly Willy** » Wed Sep 12, 2007 5:57 am

8bitwizard wrote:
evildragon wrote:Most new LCD and Plasma TVs allow you to change the overscan. Mine does, but I noticed that when it's on 0%, there usually is some black either on the right, left, bottom, or top. It's like the TV station itself has bad centering, and these were digital channels. (The HD channels didn't have this issue however)
Some LCDs (mostly for computers) aren't 16:9, they are 16:10 which is a little taller.

Also, I have a Commodore 1084S monitor which allows full vertical and horizontal size and positioning control. Want underscanned NTSC? No problem!

Actually, 16:9 is not a standard computer aspect ratio, 16:10 is. It's far easier to find 16:10 LCD monitors than 16:9. The monitor I'm using now is 16:10 (1920x1200). 1440x900 is the most common 16:10 LCD widescreen monitor you'll find right now - most 17 to 19 inch WFPs are 1440x900. Most 20 to 22 inch WFPs tend to be the next higher 16:10 resolution - 1680x1050

Speaking of the 1084S, I posted my SEGA system picture in the other thread - I happen to use a 1084 (not S) with an RGB cable. It's a very nice monitor for the SEGA. As you point out, it allows you to adjust the display for size and positioning so that you get a nice full-screen display without losing anything to overscan (unless you want to).

evildragon · Post by **evildragon** » Wed Sep 12, 2007 6:14 am

8bitwizard wrote:
evildragon wrote:Most new LCD and Plasma TVs allow you to change the overscan. Mine does, but I noticed that when it's on 0%, there usually is some black either on the right, left, bottom, or top. It's like the TV station itself has bad centering, and these were digital channels. (The HD channels didn't have this issue however)
Some LCDs (mostly for computers) aren't 16:9, they are 16:10 which is a little taller.

Also, I have a Commodore 1084S monitor which allows full vertical and horizontal size and positioning control. Want underscanned NTSC? No problem!

my TV has a "ASPCOR" option in service menu, which is a small correction.. even when off, there's black dead space on regular channels.. it's seriously in the signal, dead spots, and it's not always centered the same.. but the HD channels don't have ANY dead spots, or barely..

cdoty · Post by **cdoty** » Tue Sep 18, 2007 4:17 pm

Here's the equivalent area for NTSC:

This is based on:
http://www.interactivetvweb.org/tutoria ... sign.shtml

And agrees with 8bitwizard's 256x192 for anything important.

TmEE co.(TM) · Post by **TmEE co.(TM)** » Tue Sep 18, 2007 5:23 pm

I really hate NTSC now !!!

evildragon · Post by **evildragon** » Tue Sep 18, 2007 7:09 pm

TmEE co.(TM) wrote:I really hate NTSC now !!!

Ahh, how much I love how my TV has a PAL/NTSC/ATSC tuner :p