Buying Guides

There are many types of projectors for different occasions. Besides considering the price, lamp replacement cost and warranty, we shall look at the general specifications of projectors that school, office and home projector purchasers should specifically look out for.

Brightness (Lumens)

The brightness of a projector is measured by lumens. The higher the value, the brighter and pricier the projector becomes. The lumens range from 800 to 4,000 lumens.

For school and office use: > 2000 lumens

It is recommended to get a projector with greater than 2000 lumens for school and office use. In most cases, a little ambient light is needed for the audiences to write or read notes. Therefore a brighter projector would be ideal.

For a large room setting like lecture theaters or conference rooms, projectors with at least 2500 lumens would be ideal.

For home theater use: 800 to 1000 lumens
Home theater setups do not require bright projectors because the projection is usually displayed in a dark room. A value from 800 to 1000 lumens would be ideal.

Contrast Ratio

Contrast ratio is the measurement on the difference in light intensity between the brightest white and the darkest black. A higher contrast ratio, such as 400:1, indicates a better color representation than those of 150:1

For School and office use: 300:1 to 400:1
Since most of the school and office are viewing simple color presentations, a lower contrast ratio of 300: 1 is sufficient. For a meeting room use, 400:1 would be ideal.

For home theater use: 1000:1 to 2000:1
For movie viewing, contrast becomes very important as it reflects details of the movie. Hence, a higher contrast ratio of 1000:1 to 2000:1 would be ideal

Aspect Ratio

Images taken from "Thirteenth floors" DVD from Columbia Pictures and are slighly edited to fit this illustration.
1) 4:3 2) 16:9

There are two commonly used aspect ratios -- 4:3 (Full Screen) and 16:9 (Widescreen) There are other aspect ratios too but they are not as popular. Despite the differences, most projectors have the ability to shrink and make the images fit well on screen no matter what ratio the source is designed for. Therefore, in General, a projector should support at least these two aspect ratios.

Maximum Compressed Resolution

This screen shot is taken from Halo (PC) developed by Bungie Studios.

Images at a higher resolution are sharper and have better picture quality. The common relations to resolutions are as follows:

SVGA ( S uper v ideo g raphics a rray) - 800 by 600 (480,000 pixels)
XGA (E x tended G raphics A rray) - 1024 by 768 (786,432 pixels)
SXGA ( S uper E x tended G raphics A rray) - 1280 x 1024 (1,310,720 pixels)
UXGA ( U ltra E x tended G raphics A rray) - 1600 x 1200 (1,920,000 pixels)

Most presentations are done using XGA. Projectors that support UXGA are ideal for avid gamers.

Lamp Life

The lamp life value represents the approximate number of hours the bulb will work before a replacement is needed. The higher the lamp life, the better it is as the replacement cost for a bulb could run from S$700 to S$900.

The recommended lamp life for projectors is 2,000 hours. Some projectors have low brightness or eco modes that reduce the brightness so as to extent the life of the lamp significantly.

Projection screen size and range

One of the main advantages of using projectors over plasma TVs is the large screen size. A projector can produce images from 40-inches to as large as 300-inches for a surreal visual experience. The projection screen size co-relates to the distance between the projector and the screen. The further the placement of the projector, the larger the screen becomes.

Video Signal Inputs

Most projectors offer different kinds of input methods.

• VGA (Analog) connector - is used for connecting notebook/PC.
• DVI (Digital) connector - is used for those with newer PC graphics cards that support digital connection.
• Video S-Video - is used for most playback devices like DVD, VCR and even Camcorders.
• HDTV connectors - is used with devices that support High-definition format like DVD players and even game consoles like Xbox.

Weight

Weight is an important factor you must consider while choosing a projector as it affects the placement in your home, office and rooms. You might want to consider a lightweight projector if you have decided to place the projector overhead. For mobile warriors, it would be a wise choice to select a projector that weighs less than 1kg.

Camera & Camcorders