Video projectors are machines that project images, films and pictures on screens from another machine such as a camera, computer or TV. This works by tracking a video signal from the main machine and projecting it on to a screen.
In basic terms there are three types of video projector. The first is the CRT projector - this is one of the oldest systems in use at the moment. It uses Cathode Ray Technology (as is used by old-style TVs) to make its projections. Nowadays a lot of people will use an LCD projector instead. The technology here is Liquid Crystal Display and many people find that they get good results with this kind of projector although it can have issues on larger screens. Digital Light Processing (DLP) video projectors are more expensive but don't have the problems that might arise with an LCD system.
There are various other issues to think about when buying a video projector, including:
- What size of screen you will be using.
- What kind of brightness you will get (measured in ANSI).
- What kind of contrast you will get - higher contrast levels will give a better picture.
- What kind of resolution you'll get. This is often specified as SVGA or XGA. XGA tends to give better pictures.