Each month I visit an electrical goods store to check out the televisions. The screens get bigger, have more resolution, and are cheaper every time I look.
There are four distinct technologies generally available:
- Cathode Ray Tubes, where a large, evacuated, glass tube shoots electrons at a phosphor layer.
- Plazma, where a flat screen also makes phosphor glow with excellent contrast.
- LCD, where liquid crystals block or allow through the backlight.
- Projection, either forward or back.
The other variable is the resolution of the displays. Here are the current options:
- 625 Lines is what standard definition is today (525 for NTSC)
- 1024 (wide) by 768 (lines) is a bit better and very common
- 1920 (wide) by 1080 (lines) is real "high definition"
When you visit a shop it's not easy to find out what you are looking at. Labels such as "HD Ready" don't tell us what the screen is actually able to display. Combine this problem with the fact that as I write there isn't much true HD content around, means that it's very hard to judge the screens in a shop.
So what's the best screen technology? It's not clear unfortunately. Plazma has better blacks and therefore higher contrast but they are reputed to fade within a few years. LCDs have a poorer colour gamut but consume less power and therefore run cooler.
Computer screens are getting larger and it's likely that soon we'll be watching some sort of computer in the living room that can either record or simply download programs for direct view. Whatever happens I hope we can soon dispense with the multitude of remote controls that litter the room.
