Projectorpedia

Between July and September of this past year, 1,069,000 projectors were sold around the world. These numbers, reported by market-research firm Pacific Media Associates, represent a 20 percent increase over the same time period in 2004. Indeed, the more-than-a-million figure is a high watermark: never before have so many projectors been sold in such a short period of time.

With this influx in sales, invariably there were more first-time projector buyers than ever before. In the past couple of years, the projection industry has changed from a market ruled by integrators and IT guys to a market dominated by consumers and office workers. These days, a projector a projector is just as likely to be purchased off the Web or bought at a local technology store.

To help the newbies – or anyone who needs a refresher – Presentations has assembled a back-to-the-basics guide to projection specs. The following guide provides technical and real-world descriptions to the primary specs you'll encounter the next time you go on the hunt for a new projector.

LUMEN

Technical – A unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions.

Real-world – The unit measure of brightness used by all projection companies. In the mid '90s, the American National Standards Institute (ANSI) created a painstakingly outlined procedure for measuring lumens from a projector, which includes averaging out nine points on a screen to derive a total brightness rating. Though ANSI officially phased out its specification last year, the industry still uses the ANSI lumen as a standard measurement. In general, business projectors are 1,000 ANSI lumens and above, with most projectors falling in the 1,500 to 3,000 ANSI lumens range.


BRIGHTNESS

Technical – A quantitative measurement of a projector's maximum lamp output or luminance. Most often denoted with the lumen or ANSI lumen measurement.

Real-world – Business presentations are often held in meeting rooms with the lights on and the window shades open. Thus, the brighter your projector the better. Sharper text, clearer graphics and better overall imagery will be the result. Experts recommend at least 1,000 ANSI lumens for lights-on presenting, but in many scenarios that will even be too dim. Better to go with 1,500 to 2,000 lumens and play it safe. Keep in mind, the bigger the screen and the bigger the room, the brighter the projector you'll need. You can always turn down max brightness for venues that do not demand the power – like darkened presentation rooms and small auditoriums – but if a projector is not bright enough for an application you'll have to reassess your setup, turn down the lights or move to a different room altogether.


NATIVE RESOLUTION

Technical – The number of pixels a projector uses to create an image on the screen. The most common projection technologies – LCD and DLP – respectively create the dots of light called pixels with tiny shutters on liquid-crystal panels or micro-size mirrors on a Texas Instruments DMD chip.

Real-world – After brightness, native resolution will likely be the most important spec for business presenters. Native XGA resolution, which creates a grid of 1,024 horizontal rows of pixels and 768 vertical columns of pixels, is the standard native resolution for business projectors. XGA will provide enough detail for charts, spreadsheets and graphics. Photos and video also look good most of the time from an XGA projector. A step down in resolution, SVGA (800 x 600 pixels) is the second most common. It is less expensive than XGA but does not provide as sharp detail, though new scaling technologies sometimes make the differences hard to notice (see proceeding entry on "maximum resolution" for more details). A step up from XGA is SXGA+. This niche resolution, found on less than 1 percent of all projectors sold, provides 1,400 x 1,050 pixels, which is 47 percent more individual pixels displayed on the screen than XGA, making the difference noticeable for detailed content. WXGA resolution (1,366 x 768 pixels), SXGA (1,280 x 1,024 pixels) and HD resolution (1,920 x 1,080 pixels) are other native resolution specifications, though they are found on very few business-class projectors.


MAXIMUM RESOLUTION

Technical – The maximum resolution signal to which a projector can scale. Essentially, the highest-detail content a projector can process and display.

Real-world – Despite a projector's native resolution, every newer model can scale or process images that contain more pixels than the projector's hardware would seem to allow. Most SVGA-resolution (800 x 600 pixels) projectors, for example, can display XGA-resolution (1,024 x 768 pixels) content with ease. Internal processing takes the XGA signal and converts it to a signal that can be projected from the SVGA device. Indeed, scaling technologies have gotten so good in the past two years that some content looks just as good from an SVGA projector as it does from an XGA model. Video and photographs, especially, often make native resolution undiscernible. Similarly, many XGA resolution projectors will scale data from sources up to UXGA (1,600 x 1,200 pixels) resolution.


CONTRAST RATIO

Technical – The ratio between a projector's whitest white and blackest black.

Real-world – "Full-field" contrast ratio, which is the most common way to measure contrast on a projector, takes a luminance reading of a full-white screen and a full-black screen and divides the two in order to create a ratio. Figures like 2,000-to-1 essentially mean the brightest possible screen on a projector is 2,000 times brighter than the projector's darkest possible screen. In real use, unless your room is dark and the projected content is exceedingly complex and colorful, the projector will never utilize its maximum contrast capabilities. As a general rule, if your room is bright enough so that you can read small text on a printed page held out at arm's length, contrast on the screen will be greatly reduced, if not made irrelevant by the room's ambient light. Another important factor is the content you're projecting. PowerPoint slides with bullet points and a template background, for example, almost never exceed 300-to-1 contrast. In these cases, your fancy new 3,000-to-1 projector will be of little use. On the other hand, HD video viewed in a dark room could potentially have contrast reaching near 10,000-to-1, making even the best projectors on the market work to keep up.