The most typical question asked when looking for a new projector for the home, office, or classroom is: should I buy an LCD projector or a DLP projector? LCD, which stands for ‘liquid crystal device’ and DLP, an acronym for ‘digital light processing’ are the two top projector imaging technologies. With so many business brands and types available, it can be confusing for consumers to make a decision between both technologies. The fact is that LCD projectors offer better image quality and colour accuracy. The next paragraph will explain why DLP projectors struggle with reproducing a comparable level of image quality.

Imagine a set of blinds in your room for your bedroom window. By a twist of a rod you can turn the shutters open or closed, depending on if you want to let light in or not. And that is exactly how an LCD projector operates. Each pixel works like its own shutter on a set of blinds to either allow light through or to block it. DLP on the other hand is created of millions of microscopic mirrors or ‘pixel elements’ as the experts like to call them. Each pixel element functions to either reflect light or block it.

How the light source is processed from the time the projector switches on to when the image reaches your screen is absolutely significant in regard to image quality, brightness and colour accuracy. LCD projectors project white light from the lamp by separating it into red, blue and green components, by three mirrors which direct the coloured light to 3 stand alone LCD panels. The 3 LCD panels make the elements of the image by shining each pixel on and off. The pixels are then simultaneously processed in a glass prism to send the projector image. Something to remember about LCD projectors is that all three colours are projected onto your screen at once. The way a DLP projector works is very different and even the produced image looks is not the same. With DLP, white light from the lamp is processed through a spinning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This way of forming an image requires a sequence of red, blue and green light. The millions of micro mirrors mentioned above reflect the coloured light on the pixels to produce the image elements. The elements of the image are projected in sequence on the screen, one colour at a time. The viewer’s eyes will then pull together each coloured element of the image into the whole image. From LCD projectors, all colours are available all the time to deliver high brightness and superb colour accuracy. In DLP, only one colour is available at a time, and so resulting in lower colour brightness and accuracy. Some designers have added a white segment for the colour wheel to improve brightness generally, but this goes and detracts from colour accuracy.

I see in forums all the time that DLP offers a higher contrast ratio and as such must be superior quality. For those who are uncertain, the contrast ratio is a measure of a display system defined as the ratio of the luminance of the brightest white to that of the darkest black that the technology is capable of producing. DLP projectors do provide high contrast specifications compared to a majority of LCD projectors. At first glance, this must be an advantage, however, in the real world, the true black level is determined by the ambient light in the room where the projector is utilised. Do not be fooled by contrast specifications on websites and in brochures.

When the content you plan to view includes moving images, DLP projection technology can also create image marks, or ‘artifacts’. The most commonplace artifact that a DLP projector shows with moving images is colour break up. Colour break up is incontrovertible in DLP systems because moving images keep changing between the time red, blue and green colours are pulled up. LCD projectors do not have this problem because all the colours are processed with the others. DLP manufacturers have come up with 3DLP solutions using 3 chips to resolve the colour break up error, but the price tag of these projectors make them hardly practical for many businesses and consumers.

Another difference between LCD and DLP is how they compensate for the refractive qualities of light. Jump back to high school science, and recall how the various colours of light refract various amounts when passing through the same lens. The disadvantage with DLP projectors is that they take the one same panel for the same lens to project Red, Blue and Green. All 3 colours are not the same and refract light differently. Generally with a DLP projector, an extra yellow colour will come through above and an extra blue will show below an image containing something as simple as a straight black line. In manufacturing LCD projectors can be set to take away these effects on the projected image, because each colour is projected on its own LCD panels.

The isolated real advantage (excluding price) with going with a DLP projector is its overall smaller size and weight. However, this is only relevant to mobility and has to be traded off against the image advantages of LCD projectors. If the result of the picture quality is crucial to you, then the solution is a no-brainer. Choose an LCD projector! LCD projectors will definitely produce bright, colourful images with fewer image blips. If you need to find out more about LCD technology in more detail, check out this fabulous resource website: Explore 3LCD. If you have any further questions, jump onto Projector Central and send me an email.

Jonathan King is the sales and marketing manager with Projector Central, Australia’s leading online retailer for projectors. Brisbane based, Projector Central has been servicing Australia for 15 years. For data projectors in the Gold Coast and Interactive Whiteboards, contact Projector Central today.