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The most typical question heard when purchasing a new projector for the home, office, or classroom is: would I buy an LCD projector or a DLP projector? LCD, an acronym for ‘liquid crystal device’ and DLP, standing for ‘digital light processing’ are the two top projector imaging technologies. With so many different brands and different types available, it can be overwhelming for clients to decide between both technologies. Ultimately LCD projectors give better image quality and colour accuracy. The next paragraph will explain why DLP projectors struggle with projecting a comparable rate of image quality.

It’s like a set of blinds in your home on your bedroom window. By pulling on a rod you can make the shutters open or closed, according to if you want to let light in or not. And this is exactly how an LCD projector behaves. Each pixel works like an individual shutter on a set of blinds to either allow light through or to block it. DLP on the other hand is made up of millions of microscopic mirrors or ‘pixel elements’ as experts like to call them. Each pixel element operates to either reflect light or block it.

How the light source is processed from the point when the projector switches on to when the content reaches your screen is ultimately 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 form the elements of the image by switching each pixel on and off. The pixels are then combined in a glass prism to deliver the projector image. Something important to remember about LCD projectors is that all three colours are delivered onto your projector screen all at once. The way a DLP projector works 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 forming an image creates a sequence of red, blue and green light. The millions of micro mirrors as described above reflect the coloured light on the pixels to construct the image elements. The elements of the image are projected in sequence on the screen, one colour at a time. The viewer’s vision will then put together each coloured element of the image into a single total image. With LCD projectors, all colours are available all the time to create high brightness and fantastic colour accuracy. In DLP, only one colour is available at any given time, causing lower colour brightness and accuracy. Some developers have put a white segment into the colour wheel to improve brightness generally, but this further lessens colour accuracy.

I hear in forums all the time that DLP provides a higher contrast ratio and as such must be better 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 projector is capable of producing. DLP projectors do possess high contrast specifications as compared to most LCD projectors. Initially, this appears to be a benefit, however, in reality, the true black level is determined by the ambient light in the room where the projector is utilised. Do not be hoodwinked by contrast specifications on websites and in brochures.

When the content you wish to bring to life has moving images, DLP projection technology also creates 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 between the time red, blue and green colours are pulled up. LCD projectors do not have this downside because the colours are processed simultaneously. DLP builders have formed 3DLP solutions using 3 chips to answer the colour break up error, but the cost of these projectors make them not practical for the large part of businesses and consumers.

Another point of difference between LCD and DLP is how they balance for the refractive qualities of light. Remember back to high school science, and remember how different colours of light refract various amounts when shone 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 different and refract light in a different way. Usually with a DLP projector, an extra yellow colour will come through above and an extra blue will come through below something as simple as a straight black line. In manufacturing LCD projectors can be adapted to reduce these effects on the projected image, because each colour is directed on separate LCD panels.

The sole actual benefit (excluding price) with buying a DLP projector is its smaller overall size and weight. However, this is only relevant with regard to transporting the device and has to be traded off against the image plusses of LCD projectors. If the outcome of the picture quality is crucial to you, then the solution is easy. Go for an LCD projector! LCD projectors will definitely show bright, colourful images with fewer image imperfections. If you desire to learn more about LCD technology in more detail, check out this fabulous resource website: Explore 3LCD. If you have any further questions, go to Projector Central and send me an email.

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