Latest features of digital projectors

Digital projectors can generally be grouped into four categories: Professional presentation, Portable, Home Theater and Fixed. Some of the products that we see on the market do overlap. They can fall into the category of portable or professional presentation.

By now most users already know that the first thing to check is the maximum screen resolution that the projector can produce. Most projectors now stop at the XGA resolution, which is 1024 x 768. There are still some models that can go only as high as the SuperVGA (SVGA), which is 800 x 600.

The second feature to check out is the brightness. Some people even give this feature top priority. For them, the elimination process starts with the level of brightness. The indicator for brightness is ANSI Lumens, or simply lumens.

We decide how many lumens we would like to have based on where we are going to use the projector. If it will be used in a dark room, a projector with 1000 to 1500 lumens will be adequate.

However, if we think we are going to use it in a room with a lot of ambient light, a more powerful projector will be required. On the market there are projectors capable of producing 2500 or more lumens. Brighter projectors produce more heat, though.

If we need a portable projector, there is an increasingly wide choice. They are getting incredibly small. However, the ultra- portable projectors may not have the ability to produce a lot of lumens.

A nice portable projector that has become popular of late is the Plus V3-131. It produces 1000 lumens and weighs only 1.1 kg and is half the size of a standard news magazine. Others in the same class include the 1400 lumens InFocus LP70+ and the 1100 lumens NEC LT10.

Another feature to check out is the contrast ratio, i.e., the difference between the brightest and the darkest dot in the projected image.

The higher the ratio, the more detailed the projected image will be. This is very good for workgroup meetings, where a couple of people work together on the same document.

The difference between LCD (liquid crystal display) and DLP (digital light processor) is no longer as crucial as it was in the past. DLP projectors are cheaper, and their image quality is better for moving images. They are now almost as good as the LCD models, even for a PowerPoint presentation.

Almost all projectors today can handle different aspect ratios -- the ratio between the width and the height of the image. For movie viewing, an aspect ratio of 16:9 is preferable. For slide presentations, a 4:3 is more suitable.

However, based on the intended use, manufacturers have to decide which of these aspect ratios a particular model is optimized for. So, you will have to know whether your projector will be used more for movie screening or PowerPoint presentations.

A new breed of projectors boasts a resolution called WXGA, which means that it can throw a wider image on the screen.

What about other features? The standard features should include keystone correction, which enables us to digitally alter the geometry of the image so that they remain rectangular on the screen, although the projector is not perpendicular to the screen.

Some models use mechanical correction that shifts the lens position. Color temperature is another must if you want to use the projector for movies, so that the colors become more realistic.

Another nifty feature is Wi-Fi. It enables us to beam our presentation from a PDA. We can read our notes off the PDA as we walk about and talk to the audience, while the screen shows the slides. Models that support wireless connections to the data source come from HP, ASK Proxima and many others.

There are many other features that you can look at, but these are the essential ones. Keep in mind that the ratings claimed by the manufacturers usually exceed the real performance. So, as always, insist on a live demo before you make your decision. -- Zatni Arbi