Resolution & Brightness
A few years ago, projectors were typically a rather boring way of being able to show holiday photographs to the family or try to impress work colleagues with a dull presentation consisting of a bar charts and maybe a few pictures. However, with the increase in digital media of the last few years, a new breed of state of the art projectors are now available which have really elevated their social status to dizzy new heights!
These new LCD projectors are, needless to say, rather expensive. At a minimum you can expect to pay around $500 and prices range to over $5000. Obviously you need to decide what you are likely to be using the projector for before deciding on anything further. Although you probably have a maximum limit in mind, it is advisable to choose a projector by finding one that satisfies all your performance needs rather than choosing by cost.
There are various classes in resolution, beginning with SVGA (800x600) at the base end and improving to projectors that are twice as powerful, VXGA projectors (1600x1200). In between are XGA projectors at 1024x768, followed by SXGA at 1280x1024. If you are likely to be using your projector just for PowerPoint presentations or something similar, then an SVGA projector should be suitable, but for images with much finer detail then a projector with a higher resolution is preferable. Bear in mind that the images that you project are likely to be viewed on a 10ft screen, so an image in 800x600 may look good on your PC, but will not look good on a larger screen.
Factors to consider
There are many things to watch out for when buying a projector, but one of the most important things is the brightness. This depends on how bright the room in which the projector is to be used is likely to be. For brighter rooms, you need to purchase a more powerful projector. The brightness of projectors is measured in lumens, but be careful not to be confused between the lumen rating for overhead projectors and the ANSI lumens rating for LCD projectors. ANSI lumen ratings are usually lower but are actually more powerful.
If you are likely to be moving around, you will probably want to buy a light projector. Most projectors are around 5lbs in weight, but you can buy lighter ones, although they will be more expensive. Always look at the input ports too. The chances are you will want to use your projector with at least one computer, possibly more and maybe a DVD player too.
Another important issue is the lamp life. Often, you get what you pay for and a more expensive projector bulb will probably give a better performance and last longer too. In the long run, this may be cheaper. If your projector is to be permanently mounted, then it is far more preferable to buy a better quality projector lamp just for convenience sake.