What's the contrast ratio on a CRT?

[slash196]

Just curious, I read an article on Half-Life that mentioned game developers being limited because TFT displays can only display contrast ratios of 400:1 to 1000:1, where the human eye can see a hundred times more than that, and that affects the realism of in game lighting.

 

[ChuckHsiao]

CRT screens simply don't emit light when it's black. Thus, the contrast ratio is theoretically infinite.

However, CRT screens have glare problems, so if you're using any sort of lighting in your room, the "real" contrast ratio goes down really quick. If I remember right, it becomes around 20:1 to 30:1 in normal lighting. I'm not sure about CRTs with anti-glare coatings though. LCDs also suffer from the same problem (the only time they're anywhere near their advertised ratios is if you're in a dark room) but because the surface is inherently anti-glare, the ratio is around 100:1 or so in normal lighting.

Where LCDs fail at is with regards to near-black screens. They simply suck with them, and backlight bleeding issues on certain monitors don't help. Unfortunately, game developers currently like to use really dark levels and stuff. For some reason they think using just 10% of the brightness spectrum (regardless of CRT or LCD) makes for a better game. At any rate, aside from response time, this means that the contrast ratio should be a big concern for gamers.

 

[TheMouse]

Originally posted by: ChuckHsiao
CRT screens simply don't emit light when it's black. Thus, the contrast ratio is theoretically infinite.

However, CRT screens have glare problems, so if you're using any sort of lighting in your room, the "real" contrast ratio goes down really quick. If I remember right, it becomes around 20:1 to 30:1 in normal lighting. I'm not sure about CRTs with anti-glare coatings though. LCDs also suffer from the same problem (the only time they're anywhere near their advertised ratios is if you're in a dark room) but because the surface is inherently anti-glare, the ratio is around 100:1 or so in normal lighting.

Where LCDs fail at is with regards to near-black screens. They simply suck with them, and backlight bleeding issues on certain monitors don't help. Unfortunately, game developers currently like to use really dark levels and stuff. For some reason they think using just 10% of the brightness spectrum (regardless of CRT or LCD) makes for a better game. At any rate, aside from response time, this means that the contrast ratio should be a big concern for gamers.

Actually, I believe they use darker settings in games due to the complexity of rendering light sources. IIRC, Carmack said that current video cards were not fast enough to render a fully illuminated room of decent complexity on the Doom III engine.

 

[Sonikku]

5000:1 is what I heard for decent monitors. I don't know if there is any truth to it.

 

[Suspicious-Teach8788]

Originally posted by: Sonikku
5000:1 is what I heard for decent monitors. I don't know if there is any truth to it.

I'm sure even more. They can make 10000:1 plasma screens easily nowadays....