The component input on our TV is mixing the colours up - I’d noticed this when I got my Xbox360, but since I was connecting it via VGA, I wasn’t that bothered. Then I realised that when I pick up a Wii, I’ll be connecting that via component, and since I’d paid £1000 for the TV, it bloody better work, so an Engineer was dispatched.

This is when I realised that the guy sent to fix my TV didn’t see the difference between a composite and a component connection. Then I remembered someone posing a similar question on an art forum. Could it really be that hard to understand? I explained it to the TV guy, then thought “Hmm, thats was easy, and might make a useful post…”

Lots of people will have consoles that aren’t displaying their games as well as they could be, so I’ve written this to try to help.

Firstly, the most simple thing I can do is just list te connections in order of quality

1. RF/Coaxial
2. Composite
3. Svideo
4. Component (on a Standard-Def TV)
5. RGB Scart (Mainly European)
6. Component (on a Hi-Def TV)
7. VGA
8. HDMI/DVI

The most simple thing you can do is look at your TV to see what connections it accepts, and then you connect your console using an appropriate cable. If you’ve simply read this far and done that, you’ve probably got the best connection you can get. If you want to know WHY some connections are better than others, then read on…

So why are some better than others? It’s really all down to compression, and a lot of that has it roots in television broadcasting.

A video signal contains quite a lot of information - you are sending 50 or so different images every second. These are made up of 3 signals: Red, Green and Blue. With connections like VGA, DVI and HDMI you are sending just that - the RGB signal (along with other information, such as sync rates and perhaps digital audio). HDMI and DVI are both digital signals, which gives you best quality picture you can have since the signal is pure and unaltered.

The VGA connection also sends an RGB signal, however it gets converted to an analogue signal, then back to digital, so you have already introduced a conversion, and therefore you can lose a little clarity.

However, this is a lot of information to transmit, especially over the airwaves (and these signals have their root in TV broadcasting), so over time various methods of compression were used to be able to broadcast them more effectively. The signals get compressed to a faster method for transmission, and then they get reassembled when they are received.

Component, which has a red, a green and a blue cable doesn’t actually carry a pure RGB signal, which is pretty misleading. The Green cable carries a black and white signal, and the Red and Blue cables carry a mix of the colour. The signal gets converted to this efficient format, is transmitted along the cable and then it gets reassembled at the other end. It looks very good, but not quite as good as a pure RGB signal.

Svideo takes the same approach, but goes one step further with the two colour signals - it combines then into one, leaving you with one colour signal and one black and white signal, which is yet another step down, but it is still better than composite…

Composite is the next step down in quality, because it combines all the video signal into one wire (usually yellow). The other two cables (Red and White) carry left and right audio. Yup, 2 cables for audio and one for the picture.

The worst of the lot is RF/Coaxial which hasn’t been on a console for years, would still find it is the default on your SNES or Megadrive. It takes all that video information, and all the audio and compresses it into one tiny cable. This is also the same system most televisions have used for years.

Finally RGB SCART, mainly used only in Europe. I left it to the end cos it throws a bit of a spanner in the works depending on your TV. SCART is type of connector that allows different signals to be sent across it - composite, svideo, RGB and stereo sound. So in theory it should be better than component since it transmits RGB, and it is on standard definition TVs, but not on Hi-Def.

This entry was posted on Sunday, December 31st, 2006 at 1:38 am and is filed under Article, News, Tech. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.