The common question customers ask when buying a new projector for the home, office, or classroom is: will I buy an LCD projector or a DLP projector? LCD, standing for ‘liquid crystal device’ and DLP, short for ‘digital light processing’ are the two top projector imaging technologies. With so many different brands and models available, it can be challenging for customers to pick between both technologies. It comes down to the fact that LCD projectors give better image quality and colour accuracy. The next paragraph explains why DLP projectors struggle with projecting an equal grade of image quality.

Visualise a set of blinds in your household on your bedroom window. By pulling on a rod you can have the shutters open or closed, depending on if you want to let light in or not. And such is exactly how an LCD projector operates. Each pixel works like a single shutter on a set of blinds to either send light through or to block it. DLP on the other hand is created of millions of microscopic mirrors or ‘pixel elements’ as experts like to call them. Each pixel element works to either reflect light or block it.

How the light source is processed from the time the projector switches on to when the content reaches your screen is vitally significant with regard to image quality, brightness and colour accuracy. LCD projectors shine white light from the lamp by splitting it into red, blue and green components, by three mirrors which project the coloured light to 3 separate 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 form the projector image. An important point to realise about LCD projectors is that all three colours are sent onto your wall all at the same time. The way a DLP projector functions is widely different and even how an image comes out is not the same. With DLP, white light from the lamp is processed through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of making an image creates a sequence of red, blue and green light. The millions of micro mirrors described above reflect the coloured light on the pixels to produce the image elements. The elements of the image are sent in sequence on the screen, one colour at a time. The viewer’s eyes will then draw each coloured element of the image into the complete image. Using LCD projectors, all colours are available all the time to offer top brightness and fantastic colour accuracy. In DLP, just one colour is available at any given time, resulting in lower colour brightness and accuracy. Some manufacturers have put a white segment for the colour wheel to improve all over brightness, but this then degrades colour accuracy.

I hear in forums all the time that DLP offers a higher contrast ratio and therefore must be superior. For those who don’t 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 projector is capable of producing. DLP projectors do have high contrast specifications when compared to many LCD projectors. Initially, this appears to be an advantage, however, in real life, the true black level is determined by the ambient light in the room where the projector is being used. Do not be tricked by contrast specifications on websites and in brochures.

When the content you want to project needs moving images, DLP projection technology can also create image imperfections, or ‘artifacts’. The most typical artifact that a DLP projector creates with moving images is colour break up. Colour break up is unavoidable in DLP systems because moving images change between the time red, blue and green colours are displayed. LCD projectors do not have this characteristic because every colour is sent with the others. DLP designers have formed 3DLP solutions using 3 chips to fix the colour break up issue, but the price of these projectors make them almost impossible for most businesses and consumers.

Another variance between LCD and DLP is how they compensate for the refractive qualities of light. Jump back to high school science, and they taught you how various colours of light refract various amounts when shone through the same lens. The disadvantage with DLP projectors is that they utilise the one same panel and the same lens to project Red, Blue and Green. All 3 colours are obviously different and refract light differently. Usually with a DLP projector, some yellow colour will appear above and a superfluous blue will appear below an image as simple as a lone black line. During manufacturing LCD projectors can be adapted to reduce these effects on the projected image, because each colour is processed on separate LCD panels.

The only veritable advantage (excluding price) with deciding on a DLP projector is its smaller total size and weight. However, this is only relevant with regard to transporting the device and must be traded off against the image advantages of LCD projectors. If overall picture quality is vital to you, then the decision is a no-brainer. Go for an LCD projector! LCD projectors will consistently produce bright, colourful images with fewer image errors. If you wish to know more about LCD technology in more detail, have a gander at this spectacular resource website: Explore 3LCD. If you have any more questions, jump onto Projector Central and send me an email.

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