Selecting and purchasing the appropriate digital projector for your cinema's pre/post feature entertainment, advertising, alternate content, and other uses can be daunting.
With hundreds of models from numerous manufacturers on the market it's difficult to make a selection as to which is best suited for your requirements and which offer the best value with those features.
The first decision will be how large a projector. This means, how many lumens (a measure of brightness) will be required - given the screen size and picture throw (distance from projector to screen) - to provide a very good (i.e. HDTV quality) on-screen image.
There are no fixed rules for determining brightness; however, I have found that to get a good, bright image on a typical matte white, peforated cinema screen requires about 50 - 100 lumens per foot of picture throw. For example, an auditorium with a throw of 50 ft. will require a projector with 2500 - 5000 lumens (and it's preferable to error on the high side). This will provide a bright image whether running a PowerPoint presentation (with house lights up) or a DVD movie presentation.
There are small, desk-top projectors on the market that advertise 3, 4, or even 5,000 lumen capability, but don't make the mistake of purchasing a small (less expensive) projector as the internal components, standard features, and expandability options you desire, may be lacking. Also, make sure the projector you select has a lot of internal cooling capability. Heat, dirt, and erratic power levels are the worst enemies of all digital projectors.
As noted, it's always better to error on the side of more lumens so as not to be operating the projector "full out" all the time. This will put less stress on the internal components and the optical system as well. Rule: It's better to purchase a 3,500 lumen projector and run it at 2,500 than a 2,500 lumen projector and run it at maximum capacity.
ASK - Dell - InFocus - Philips
Barco - Epson - LG - Sanyo
Canon - Hitachi - Optima - ViewSonic
Determining the appropriate lens can be tricky. In the world of digital projection, as a general rule, dividing the image throw by the screen width will determine the lens size. For example, if the image throw is 50 ft. and the screen is 30 ft. wide the lens required is 1.62. Most cinemas require long-throw lenses and most of these have variable (zoom) focal lengths.
Be prepared, as most cinemas cannot use the standard lens which normally comes with the projector and in most cases will have to be upgraded to the rquired lens. Also, a projector with a motorized lens shift (vertical & horizontal) is best, particularly if placing the projector off the screen's center line of view.
What content sources will you be interfacing with your projector, DVDs, VHS, laptop, HD video, BETA, USB Flashcards, High Speed Internet? Rule: Make sure the projector you are purchasing can accept a wide variety of source components. Additionally, a projector with internal switching and scaling features is well worth the extra cost if you plan on using various source components.
Best Bet: Don't purchase any projector unless it has at a minimum the following inputs: DVI (digital input) HDMI (high definition multimedia interface) composite video, s-video, and USB ports.
A multi-lamp modes feature is very desirable. A lamp economy mode will prolong a lamp's burn life. If you envision the projector getting a lot of use or you are exhibiting content you are charging for then it's imperative to purchase a projector with dual lamp capability.
Never purchase a projector based solely on price. Plan ahead and use the information in this article to give you a start, to calculate: image size, minimum lumens required, lens sizing, minimum connection interfaces, and content source components.
Also check out the projector's required servicing and maintenance. As with all digital projectors the biggest problems stem from dust and dirt accumulation, inadequate cooling and improper maintenance.
By James Lavorato, excerpted from Summer 2006 issue of The Marquee magazine, published by Entertainment Equipment Corporation.