The typical question heard when buying a new projector for the home, office, or classroom is: should I buy an LCD projector or a DLP projector? LCD, an acronym for ‘liquid crystal device’ and DLP, which stands for ‘digital light processing’ are the two most popular projector imaging technologies. With so many brands and different types available, it can be confusing for consumers to choose between those technologies. Ultimately LCD projectors have far superior image quality and colour accuracy. The next paragraph will tell you why DLP projectors struggle with creating a similar rate of image quality.

It’s like a set of blinds in your home for your bedroom window. By twisting a rod you can make the shutters open or closed, according to whether you want to let light in or not. That is exactly how an LCD projector works. Each pixel works like its own shutter on a set of blinds to either pass light through or to block it. DLP on the other hand is made up of millions of microscopic mirrors or ‘pixel elements’ as professionals like to call them. Each pixel element works to either reflect light or block it.

How the light source is processed from the point when the projector is switched on to when the image reaches your screen is extremely significant in regard to image quality, brightness and colour accuracy. LCD projectors process white light from the lamp by splitting it into red, blue and green components, by three mirrors which project the coloured light to 3 individual LCD panels. The 3 LCD panels form the elements of the image by shining each pixel on and off. The pixels are then meshed in a glass prism to form the projector image. An important point to remember about LCD projectors is that all three colours are delivered onto your projector screen at the same time. The way a DLP projector runs is vastly different and even the final product of how an image looks is not the same. With DLP, white light from the lamp is projected through a turning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This way of creating an image forms a sequence of red, blue and green light. The millions of micro mirrors described above reflect the coloured light on the pixels to construct the image elements. The elements of the image are sent in sequence on the screen, one colour at a time. The viewer’s eye will then put together each coloured element of the image into a complete image. In LCD projectors, all colours are available all the time to create the top level of brightness and superb colour accuracy. In DLP, only one colour is available at any given time, and so resulting in lower colour brightness and accuracy. Some DLP manufacturers have added a white segment for the colour wheel to improve brightness overall, but this goes and detracts from colour accuracy.

I see in forums all the time that DLP offers a higher contrast ratio and therefore must be superior quality. For those unaware, 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 system is capable of producing. DLP projectors do provide high contrast specifications when compared to most LCD projectors. At a glance, this must be a benefit, however, in truth, the true black level is determined by the ambient light in the room when the projector is used. Do not be duped by contrast specifications on websites and in brochures.

When the content you want to bring to life has moving images, DLP projection technology can also create image marks, or ‘artifacts’. The most often seen artifact that a DLP projector creates with moving images is colour break up. Colour break up is to be expected 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 disadvantage because the colours are sent with the others. DLP developers have come up with 3DLP solutions using 3 chips to solve the colour break up artifacts, but the cost of these projectors make them impractical for many businesses and consumers.

Another differentiation between LCD and DLP is how they make up for the refractive qualities of light. Take yourself back to high school science, and recall how various colours of light refract different amounts when directed through the same lens. The downfall with DLP projectors is that they have the one same panel for the same lens to project Red, Blue and Green. All 3 colours are obviously not the same and refract light differently. Most of the time with a DLP projector, a superfluous yellow colour will be projected above and a spill of blue will come through below something as simple as a straight black line. In building LCD projectors can be fixed to reduce these effects on the projected image, because each colour is processed on isolated LCD panels.

The only true advantage (excluding price) with choosing a DLP projector is its smaller overall size and weight. However, this is only relevant with regard to transporting the device and cannot be traded off against the image superiority of LCD projectors. If the result of the picture quality is important to you, then the decision is a no-brainer. Go with an LCD projector! LCD projectors will definitely produce bright, colourful images with fewer image imperfections. If you want to ask more about LCD technology in more detail, see this fantastic resource website: Explore 3LCD. If you have any more questions, go to Projector Central and send me an email.

Jonathan King is the sales and marketing manager of Projector Central, Australia’s premier online provider for projectors. Brisbane-based, Projector Central has serviced Australia for 15 years. For data projectors in Brisbane and Interactive Whiteboards, contact Projector Central today.