What will you be using the projector to do? Does it need to be wall- or ceiling-mounted, or should it be portable for use in many different rooms? Projectors come in many shapes and sizes, and some are designed specifically for lightweight ease of movement.
Lumens are the measure of a projector’s brightness, the same as watts are to lightbulbs. If your projector will sit in a space where you can dim the lights, then a basic projector — usually between 1,500 and 2,000 lumens — will probably be the best fit. At the other end of the spectrum, an outdoor situation with full natural light will overpower any projector. Consult an audiovisual technician for a recommendation based on your event or installation.
Remember that anytime you use a digital projector, you’ll need at least two accessible outlets, if not three or more: One for the projector, another for the source (computer, cable box, DVD player), and more for a speaker or sound system if applicable. If you run cabling across a room to allow for your audiovisual setup, make sure you cover these cables so people don’t trip over them.
Larger projectors require 220-volt power. This requires wiring and installation, so if you only need to use a large projector for a one-off event, try to schedule that event in a location with 220-volt outlets already installed.
Throw distance tells you how far the projector must sit from the screen to produce the image you want. Most consumer projectors are about 2:1, meaning a 6′ picture comes from a projector situated about 12 feet away. You can choose both short- and long-throw lenses to cover almost any distance, but the projector will also lose brightness the further it is away — a qualified technician will help you determine how much brighter the projector should be to compensate. Large venue projectors (usually 5,000 lumens or greater) have a different array of throw options and adjustments than consumer projectors. Think of this the same way as the difference between a consumer digital camera and a professional one: same basic function, way more options.
The angle from projector to screen affects your result too. If possible, the best way to position the projector is so that it points directly at the center of the screen. When the projector must tilt up or down or angle to one side, digital correction — which is, technically, a distortion in itself — can diminish the quality of your image.