The most common question customers ask when acquiring a new projector for the home, office, or classroom is: will I buy an LCD projector or a DLP projector? LCD, which stands for ‘liquid crystal device’ and DLP, short for ‘digital light processing’ are the two most common projector imaging technologies. With so many business brands and different models available, it can be confusing for customers to make a choice between those technologies. The simple fact of the matter is that LCD projectors offer superior image quality and colour accuracy. The next paragraph explains why DLP projectors struggle with projecting a comparable standard of image quality.

Visualise a set of blinds in your household covering your bedroom window. With the twist of a rod you can make the shutters open or closed, depending on if you want to let light in or not. Such is exactly how an LCD projector functions. Each pixel functions like a unique shutter on a set of blinds to either shine light through or to block it. DLP on the other hand is created of millions of microscopic mirrors or ‘pixel elements’ as pros like to call them. Each pixel element functions to either reflect light or block it.

How the light source is processed from when the projector switches on to when the picture reaches your screen is extremely significant in regard to image quality, brightness and colour accuracy. LCD projectors shine white light from the lamp by separating it into red, blue and green components, by three mirrors which transfer the coloured light to 3 stand alone LCD panels. The 3 LCD panels cast the elements of the image by processing each pixel on and off. The pixels are then simultaneously processed in a glass prism to deliver the projector image. Something to realise about LCD projectors is that all three colours are directed onto your screen all at once. The way a DLP projector runs is totally different and even the way an image comes out is not the same. With DLP, white light from the lamp is sent through a spinning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of projecting an image casts a sequence of red, blue and green light. The millions of micro mirrors as described above reflect the coloured light on the pixels to create the image elements. The elements of the image are sent in sequence on the screen, one colour at a time. The viewer’s vision will then combine each coloured element of the image into the whole image. Using LCD projectors, all colours are available all the time to form the best brightness and great colour accuracy. In DLP, only one colour is available at any given time, and so resulting in lower colour brightness and accuracy. Some DLP designers have placed a white segment into the colour wheel to improve general brightness, but this then degrades colour accuracy.

I read in forums all the time that DLP offers a higher contrast ratio and thus must be superior quality. For those who do not know, 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 machine is capable of. DLP projectors do provide high contrast specifications in comparison to a majority of LCD projectors. At a glance, this seems to be a plus, however, in reality, the true black level is determined by the ambient light in the room where the projector is used. Do not be hoodwinked by contrast specifications on websites and in brochures.

When the content you plan to see requires moving images, DLP projection technology can also have image imperfections, or ‘artifacts’. The most commonplace artifact that a DLP projector shows with moving images is colour break up. Colour break up is to be expected in DLP systems because moving images change up between the time red, blue and green colours are shone. LCD projectors do not have this downside because all colours are sent with the others. DLP manufacturers have come up with 3DLP solutions using 3 chips to fix the colour break up artifacts, but the price tag of these projectors make them hardly practical for the large part of businesses and consumers.

Another difference between LCD and DLP is how they match the balance for the refractive qualities of light. Think back to high school science, and recall how the various colours of light refract different amounts when passing through the same lens. The downfall with DLP projectors is that they use the one same panel and the same lens to project Red, Blue and Green. All 3 colours are not the same and refract light in different ways. Often with a DLP projector, some yellow colour will appear above and some blue will be projected below an image as simple as a straight black line. During manufacturing LCD projectors can be adapted to remove these effects on the projected image, because each colour is directed on a separate LCD panels.

The one actual advantage (excluding price) with choosing a DLP projector is its overall smaller size and weight. However, this is only relevant for portability and has to be traded off against the image plusses of LCD projectors. If the outcome of the picture quality is vital to you, then the answer is a no-brainer. Take an LCD projector! LCD projectors will constantly show bright, colourful images with fewer image mistakes. If you want to learn more about LCD technology in more detail, have a look at this fantastic resource website: Explore 3LCD. If you have any further questions, visit Projector Central and send me an email.

Jonathan King is the sales and marketing manager at Projector Central, Australia’s number one online store for projectors. Brisbane based, Projector Central has been serving Australia for 15 years. For data projectors in the Gold Coast and Interactive Whiteboards, contact Projector Central today.