The ideal overscan percentage for NES/SNES/PS1, etc?

[Zing]

I have meticulously calibrated my CRT TV to have 5% overscan on each side. This is perfect for my NES, SNES, and PlayStation, as nothing is cut off at the top or bottom of the screen. However, I noticed that these systems don't have active content to the complete left and/or right side.

For example, we all know the NES has quite a bit of "overscan" on the sides, where it just fills in the display with the background colour. At 5% overscan on the TV, this NES "overscan" is able to be seen and is often distracting.

Another example is with the SNES, where the game's "area" doesn't extend completely to the sides. This also occurs with the PlayStation, and is in fact immediately obvious during the white PlayStation logo boot screen. I can see the blank area between the background colour and the edge of the TV screen. This isn't as annoying as with the NES, since it is just blank, but it still attracts the eye and makes geometric distortions very apparent.

Basically, 5% is the ideal overscan setting for the top and bottom, but it is too low for the sides! I could fix this by extending the side overscan to something like 7% or more, but that should affect the aspect ratio, making the game image slightly wider than intended.

Am I missing something? Are these old systems designed to be wider than a fixed 4:3? It's very puzzling to me. I need to find a NES/SNES game that has a perfect square or circle so I can test the aspect ratio of the output. I am using a DVD player to adjust my overscan, but maybe the 240 line scan rate is different? If only my DVD player could output at 240p.

Any ideas?

[Hobie-wan]

Older TV tubes were not only a rounded surface, but the edges were rounded as well. The picture being thrown at the tube had to be a little bigger so it would reach the edges and the corners were cut off a little. Also some Broadcast equipment puts information in the overscan area that related to tape counters and things. Of course with flatter rectangular screens and LCD/Plasma that don't have overscan this is a problem when hooking older equipment.

http://en.wikipedia.org/wiki/Safe_area

[Zing]

5% is clearly safe enough for these consoles, and it falls within the Avia calibration DVD safe area. What I am wondering is if, for whatever reason, these 240p sources are optimally run with a wider than 4:3 aspect ratio.

I guess I am just wondering if a TV with the geometry calibrated for normal TV/DVD use is not ideal for a 240p source, as the consoles do not fully output in the horizontal directions.

Maybe I am just over thinking this and should accept the blank areas on each side of the screen.

[Hobie-wan]

It may also be due to the way the screen is being scrolled and how the video memory works on them. I've seen some games that have a little bit of garbage at the edges of the screen where graphics popped in. When that happened in the overscan area it wasn't an issue and was planned for with older TVs.

[Zing]

The problem is that, if "older TVs" had the overscan high enough to hide the sides of the image, it would also hide the top and bottom. It is fine with the sides, since it is just garbage or blank, but the top and bottom display the scores, etc. I guess I just don't remember not being able to see my score in Super Mario Bros on my parent's 25" Sears television 20 years ago. With my overscan set to 5%, the SMB score is almost touching the top of the screen. If I set my overscan to 7-8% to hide the sides, then the score would be half hidden!

I guess a difference of a few percent probably isn't even enough to perceive circles not being perfectly circle, so I could just leave the top/bottom at 5% and adjust the sides to 7%.

[Hobie-wan]

I remember seeing plenty of poorly adjusted TVs growing up at people's houses where 8 and 16 bit scores and things were partially hidden.

[Jamisonia]

If you're using this TV primarily for video gaming then just bring up the service menu during a game and adjust it based on that.

I know you also used the Avia DVD for picture calibration. Can you tell you how your brightness checks out with a game like Zelda 64? I'm just wondering because I used Video Essentials on LD (sort of figured the analog nature of the calibration might be better for video games), and I found that it was far took dark for Zelda 64's brightness calibration. Is Avia (and I assume by extension Video Essentials on DVD) check out?

I've been interested in putting together a guide for picture calibration for a TV used primarily for video game systems, although idk if its possible to make a settings that are ideal for cartridge based games as well as disc based games.

[Zing]

Calibrated using the DVD creates an image that is very good for everything from the NES to the Wii. Nothing is too dark or too bright and the colours look great.

[vlame]

i use thx optimizer for my tv.

[DinnerX]

I just eyeball all my settings. Different settings make different games look better. My various inputs don't get affected evenly by the picture settings anyway. Never messed with the service menu.