Buyer's Guide - Projectors
When purchasing a projector, there are several factors you should consider. The most important considerations are resolution, weight, and brightness. Cost will generally be a function of these factors, though other minor traits will also play a role.
When chosing the resolution for your projector, you will want to identify the resolutions that can be output by the computer you will be using. Some computers with non standard screen sizes (widescreen laptops, netbooks, etc.) may not be able to produce an output signal at the native resolution of the projector you are using, resulting in portions of the image being cut off.
Higher resolution projectors
are able to better show finer detail, but will generally cost a great deal
more. Most projectors are SVGA or XGA, but you can get higher
resolutions if you are willing to pay more.
If you are looking
to display video, DVD, and some limited PowerPoint, an SVGA, which is
capable of 800 X 600, will most likely do. XGA (1024 X 768) or WXGA (1280 X 800) will look nicer and would be recommended if your budget allows.
SXGA (1280 X 1024), SXGA+ (1400 X 1050), UXGA (1600 X 1200), and WUXGA (1920 X 1200) will be much more expensive, and as such are only recommended for users who know they need extremely high resolution.
Most projectors weigh between five and eight pounds. There are good projectors available that will be under five pounds, but they will typically cost a great deal more. 5-8 pound projectors will typically be more fully featured than those under 5 pounds. Projectors heavier than 8 pounds are available, and may offer certain advantages to users who do not wish to travel extensively with them.
For even more portability you can consider the new line of Pico Projectors. Some options are as follows:
On the Personal side, you can find them here:
On the Departmental side, you can find them here:
These Pico Projectors are incredibly small and lightweight. They measure around 1.97" x .59" x 4.06" and weigh approximately 4 oz.
Brightness will play a major role in how usable the projector is. In situations in which the projected image will be extremely large, an extremely bright projector will be preferable because it will maintain a more easily readable image over a greater area. Ambient light in the room in which you will be using the projector also dictates partially the brightness you require. In a perfectly dark room, a rather dim projector will be visible without problem, while a room with a great deal of ambient light requires a very bright projector to remain usable. Even the screen upon which you will be projecting can play a role in determining your brightness needs. Walls are poor reflectors of light, while projection screens reflect a great deal of light, decreasing the need for a bright projector. Most projectors are between 2000-3000 ANSI Lumens. Less than this will be rather dim, and more than this is considered pretty bright.
Types of Projectors
Projectors come in two main types: LCD, and DLP.
|LCD (liquid crystal display) projectors project light through 1 or 3 small LCD panels where it is focused out. LCD projectors tend to be larger than DLP projectors (though far smaller than CRTs), and less bright, but are generally regarded to have better color and contrast than DLP.|
|DLP (digital light processing) projectors usually have one chip, which has tiny mirrors that rotate. Light is shone on the chip, and is reflected back through a color wheel and out to the screen. DLP projectors are smaller, lighter, cheaper, and brighter than LCD and CRT, however, they often have poorer color and contrast ratios than the others. DLP may also be probelmatic in some cases because the color wheel may cause color artifacts to appear when moving images are displayed.|
Contrast ratios can also play a role in how well your projector will meet your needs. As on LCD displays, the higher the contrast ratio, the brighter the whites, and the darker the blacks. A typical contrast ratio will fall between 200:1 and 2000:1, with a larger ratio generally being better.
Image size is the maximum and
minimum sizes above and below which a projector will not focus. This is
an especially important thing to consider, as the further away the projector
is from the screen, the larger the image gets. Most will quote screen
sizes of between 40 inches and 300 inches diagonally. Small desktop projectors
will require a smaller throw distance for an image than most full sized
projectors. Look at manufacturers' websites for projector calculations
or at www.projectorcentral.com.
Connection types are the last, but certainly not the least important factor you should consider. Almost all projectors will take composite (the yellow rca jack), s-video, and VGA inputs. Better projectors will have DVI inputs, but those will very often come with VGA adapter cables. Some will also accept component or HDMI (hi-definition) signals.
As a further note about projectors, the DoIT TechStore does not stock replacement lamps, though replacement lamps can be ordered through the DoIT TechStore. Replacements should be ordered before they are strictly necessary, to avoid downtime in your projector use.