Product Survey: Full HD Projectors
The Bulb Issue
Projectors have one consumable that needs to be replaced: the bulb. After an average of 2 000 hours of use, it has to be changed and a new bulb will run you several hundred dollars. Two thousand hours might not seem like much, but if you watch three two-hour films a week, you won't need to change your bulb for six years.
If you are a real gaming buff and want to connect your console though, using it for two hours a day will result in changing the bulb after three years.
For everyday use, it's still worth sticking to a traditional TV and keeping the projector for special occasions. After all, you don't need a twelve foot screen to watch tomorrow's weather forecast.
It's easy to split the market for video projectors into two very clear segments, with HD Ready (720p) models on one side and Full HD )1080p) models on the other.
Full HD projectors are the top-of-the-range options for most manufacturers. They usually include the most advanced technologies--which has a very obvious effect on the price. Nasty surprises aside, you won't find any bad choices in this sector of the market, and all of the projectors we've tested create an excellent image, especially when you use a Blu-ray disc as your source. The differences between one model and another are more to do with small details like color handling, ease of use or upscaling, where even a small advantage can allow one particular projector to edge ahead of the competition.
Two rival technologies are at war: some use DLP technology, but others use LCD. The two systems work in different ways and produce different results. DLP fans enjoy deeper blacks and the total absence of ghosting, but LCD projectors can produce larger images at the same distance from the screen, and don't produce the 'rainbow effect', which leads some users to see flashes of red, green and blue when watching DLP projections.
Here are the technical differences:
DLP - Digital Light Processing: This system is based on three elements: a light source, a color wheel, and a DMD (Digital Micromirror Device) chip. The color wheel is divided into segments of three different colors--red, green and blue--and as it spins, it splits up the white light from the lamp. These color fragments are then reflected by the tiny mirrors on the DMD chip, whose position varies by up to 10° to send a particular image towards the projection lens. Your eye then reconstructs the colors of the final image by fusing all of the colors reflected by the mirrors. For example, when these mirrors rapidly reflect red and green light, you will see yellow. The number of mirrors in the chip is equal to the resolution of the projector. For example, a resolution of 1280 x 720 pixels requires 921,600 mirrors.
LCD - Liquid Crystal Display: This system is comprised of a lamp, two prisms and three LCD panels. The first prism is in charge of separating the light the lamp emits into the three components of red, green and blue. Thanks to a series of mirrors, the separate light rays each hit an LCD panel which, depending on the position of its cells, may or may not let the light through. A last prism placed between the panels recombines the three light beams and sends the image through a projection lens.