Question about Overscan

[TrekkiesUnite118]

Not sure if this fits here or not but I figured I'd ask this since I remember a couple people here mentioning overscan with their Genesis systems and messing with the service menu to eliminate it and what not. I've noticed something with my Samsung TX-R2035 CRT TV. When I'm watching my DBZ Dragonbox DVDs in my DVD player using composite or my PS2 using component, there is very noticeable overscan.

Here is how the source image looks on my computer:



And this is close to how it looks going through my DVD player or my PS2:



Now here is where I noticed something interesting. If I hook my computer up to my TV through composite, I get the same image as the first image I posted above, meaning little to no overscan. So I am wondering here, is my TV to blame for this? Or is it my DVD player and PS2 causing this? Or is it something with how my PC outputs to my TV?

[Guntz]

I'm pretty sure most tube TVs won't show the overscan, but all PC capture card collects the entire video image (well, as far as I've seen). Don't worry about not seeing any overscan.

[tomaitheous]

Almost any TV can be set to show full overscan. And expensive (good quality) sets are usually setup to about 3% overscan.

Your TV is to blame. You PC running over composite or s-video isn't doing 1:1 NTSC resolution. It's being scaled in a frame buffer before being sent out. Usually, most TV encoders on the video card itself - have an app to control 'overscan' of TV out. But this is just scaling. I.e. it's to help when you have a target TV that you can fix the overscan, and you need to see as much of the PC screen as possible. I.e. text for power point and such.

Don't worry about the overscan much. All professional video is supposed to be setup so that nothing important is in the overscan area. So you're not really missing much. Fixing or adjusting it might require either finding out how to enter the service menu on your TV or adjusting some pots inside the TV (meaning you have to open it up). It's rare, but I've seen V and H size pots that you can setup from the outside of the TV (old CRTs). The down side of this, of course, is that you'll see the overscan borders of your old game consoles.

[TrekkiesUnite118]

Thanks for answering that. I don't really worry about the Overscan that much either, it was just something I noticed really. On another note how is overscan calculated? I'm curious to know what the percentage on my set is.

To be honest I can already see the overscan borders when playing my Genesis.

[Waterfaller]

I think overscan is pretty different for every TV set. One I had was so bad that it made playing some games harder than they needed to be. Important information either near the bottom or the left edge were noticeably cut off. From what I understand though, it can be affected by what direction your TV is facing. Something to do with the magnets inside compared to a northerly direction. Or something like that.

I've gotten entirely spoiled by my LCD set though. Everything is now perfectly visible.

[kool kitty89]

It seems a fair amount of newer TVs don't allow horizontal overscan adjustment via the service menu, but only vertical (I discovered that's the case with our ~6 year old 27" flat Sanyo CRT) and old ones (talking 80s or older -maybe not even some really late 80s stuff) have manual scan adjustment via potentiometers. (sometimes accessible externally on really old sets -that's the case with my late 60s GE portacolor)

I have noticed the Wii is especially bad at managing overscan safe graphics (both in terms of games and otherwise -you see a lot of text disappear over the edge in the browser or using Netflix, and I've seen it to a rather significant degree in commercial games).

Never any problems with vertical overscan given that TV's almost always in 16:9 compressed (anamorphic) mode.

[GohanX]

I also have a Samsung CRT and the overscan was pretty brutal, the geometry was a bit off, and it displayed too much red. I fixed most of this in the service menu, although there is still some overscan (as there should be.)