How is a TV differant from a PC monitor?

[SonicIce]

(Talking about CRT technology only) What is the resolution of a standard definition TV? Does it vary depending on build quality? When I play a console game and its rendering internally at 640x480, it looks much higher than that, I would have to guess 1024x768 at least with a nice TV playing a new game like Halo. 640x480 on a PC monitor really looks alot worse. What is the refresh rate of most TV's 100Hz or so? Maybe it looks better because you sit so far away?

 

[Peter]

TV CRTs have HUGE dot pitch, low bandwidth, and less than impressive focus. That's inbuilt full screen antialiasing if you want to say something positive about it.

TV signal refreshes HALF the picture 60 or 50 times a second (depending on where in the world you are). More advanced units have a screen buffer, doubling the tube refresh rate to reduce flicker. But still, no more than 30 or 25 full frame updates per second.

 

[ChuckHsiao]

American TVs run at 30 frames a second, so that's 30 Hz (actually, 29.97 Hz but close enough). No idea about other countries. It looks good because you're (supposed to be) sitting so much farther away from it. Most people don't adjust the brightness down when they sit closer the way they do with a computer monitor.

A TV is only maybe double or triple the size (in each direction) of a computer monitor, but you're not only sitting twice or three times farther away -- maybe more like across the room. That's why it looks good on TV. You wouldn't notice any resolution effects if you were looking at a computer monitor from the same proportional distance away.

The vertical resolution is um, 525. Or 480. Or um something like that. I'm too lazy to figure it out, but you can try here:

http://members.aol.com/ajaynejr/vidres.htm

Edit: I forgot to say, another reason is that we don't usually read text on a TV -- or when we do, it's usually not a single pixel wide. Computer monitors (LCDs in particular) mess up because the text is usually meant to be a single pixel wide, so if there's any interpolation or other junk involved, the quality really suffers. TVs generally only show video instead.

 

[Peter]

Visible vertical resolution is 480 lines for NTSC and everything else 60 Hz, and 576 lines for PAL and everything else 50 Hz. Note that it's always interlaced, meaning that only every other display line is updated in alternating frames.

That again means that if you want to display a steady pixel, you need to make it two lines high, cutting the available vertical resolution for text in half.

 

[SonicIce]

So it's possible to play a videogame at true 60fps but interlaced, because there is an obvious differance between games that run at 60 and games at 30. what about the horizontal resolution? im guessing its 640 since the vertical is 480 and the aspect ration is 4:3.

 

[SonicIce]

hi

 

[YOyoYOhowsDAjello]

Yeah, regular tvs are 480i, so 640x480, but interlaced as has been said already.

 

[Peter]

Originally posted by: SonicIce
So it's possible to play a videogame at true 60fps but interlaced, because there is an obvious differance between games that run at 60 and games at 30. what about the horizontal resolution? im guessing its 640 since the vertical is 480 and the aspect ration is 4:3.

Computer generated imagery will use 640 pixels on NTSC and 768 on PAL, for squareness of each pixel; DVD are produced at 720. _Actual_ signal bandwidth doesn't let more than about 360 pixels come out actually separated.

Stuff claiming to run at 60 Hz just plainly doesn't.