Education Projectors Buyer's Guide
Image Resolution - That image you see projected on the screen is essentially a lot of tiny dots, each representing a part of the total picture. If you took a photo and ran it through a shredder many times, all those little specs of photo paper could in theory be put back together to recreate the original photo. This is essentially what a projector does. It takes an image that is broken into tiny bits known as pixels and projects each of these pixels onto the screen in an orderly manner; thereby, creating an image.
The greater the number of pixels the greater the resolution of the projector and the more pleasing the image is whether you're looking at text or video. The resolution of your projector determines the level of image detail your projector can deliver.
Resolution is described in two ways. The most common is an acronym like SVGA, XGA, WXGA, and HD. The other is the number of horizontal and vertical pixels that the projector is capable of displaying in width and height. SVGA is 800 x 600, XGA is 1024 x 768, HD 720 is 1280 x 720, and HD is 1920 x 1080.
So if you bought an XGA projector your image would be 1024 pixels wide and 768 pixels high. More pixels will give you better image detail especially when you enlarge the image as you would with a projector. If you have selected a 4:3 aspect ratio, your primary choices will be SVGA or XGA and of the two XGA would deliver a better image with all other things being equal.
Although higher resolution comes at a cost, today's XGA projectors are very competitive in price, offer 64% more resolution, and there are many times more projectors from which to choose. Be aware that some applications, most notably Apple's iMovie, require XGA as a minimum video resolution. So, once again, consider your material and choose accordingly.
Color Resolution - Color resolution is much like image resolution, except in this case we're talking about the number of colors that each pixel is capable of generating. The more colors each pixel can create, the more life-like the image will be.
Back in the early 90's when the digital projection industry was taking hold, the goal was 16 million colors per pixel. Today we've moved well beyond that; new projectors are boasting more than 68 billion colors per pixel. Don't try to count them. You don't have the time. That's enough color resolution for us mere mortals.
In summary, resolution is about image detail and color detail. The color detail is essentially there for all projectors. It's the image detail where the benefits are today. So give careful thought to the pixel resolution you choose. You can never have too much, other than the impact on your budget.