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The most typical question heard when looking for a new projector for the home, office, or classroom is: should I buy an LCD projector or a DLP projector? LCD, standing for ‘liquid crystal device’ and DLP, standing for ‘digital light processing’ are the two most common projector imaging technologies. With so many company brands and different models available, it can be confusing for the buyer to decide between both technologies. It comes down to the fact that LCD projectors offer far better image quality and colour accuracy. The article below tells you why DLP projectors struggle with reproducing an equal grade of image quality.

It’s like a set of blinds in your home on your bedroom window. With the twist of a rod you can turn the shutters open or closed, according to if you want to let light in or not. And such is exactly how an LCD projector functions. Each pixel operates like an individual shutter on a set of blinds to either allow light through or to block it. DLP on the other hand is formed of millions of microscopic mirrors or ‘pixel elements’ as pros 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 turns on to when the content reaches your screen is absolutely significant for image quality, brightness and colour accuracy. LCD projectors direct white light from the lamp by splitting it into red, blue and green components, by three mirrors which direct the coloured light to 3 individual LCD panels. The 3 LCD panels create the elements of the image by processing each pixel on and off. The pixels are then meshed 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 all at the same time. The way a DLP projector operates is totally different and even the way an image comes out 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 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 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. From LCD projectors, all colours are available all the time to form the best brightness and fantastic colour accuracy. In DLP, only one colour is available at once, resulting in lower colour brightness and accuracy. Some DLP manufacturers have included a white segment into the colour wheel to improve brightness overall, but this further lessens colour accuracy.

I see in forums all the time that DLP has a higher contrast ratio and ergo must be superior. For those 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 system is capable of producing. DLP projectors do provide high contrast specifications when compared to most LCD projectors. Initially, this appears to be a plus, however, in real life, the true black level is determined by the ambient light in the room where the projector is utilised. Do not be tricked by contrast specifications on websites and in brochures.

When the content you want to see requires moving images, DLP projection technology can also have image imperfections, or ‘artifacts’. The most often seen artifact that a DLP projector forms with moving images is colour break up. Colour break up is incontrovertible in DLP systems because moving images change between the time red, blue and green colours are projected. LCD projectors do not have this characteristic because all colours are projected at the same time. DLP manufacturers have come up with 3DLP solutions using 3 chips to solve the colour break up artifacts, but the price of these projectors make them not practical for most businesses and consumers.

Another differentiation between LCD and DLP is how they match the balance for the refractive qualities of light. Take yourself back to high school science, and remember when they taught you how different colours of light refract different amounts when directed through the same lens. The disadvantage with DLP projectors is that they take the one same panel and the same lens to project Red, Blue and Green. All 3 colours are obviously not the same and refract light in a different way. Most of the time with a DLP projector, a spill of yellow colour will be projected above and a spill of blue will come up below something as simple as a single black line. While being built LCD projectors can be set to reduce these effects on the projected image, because each colour is directed on its own LCD panels.

The only actual benefit (excluding price) with going with a DLP projector is its smaller total size and weight. However, this is only relevant to transporting the device and must be traded off against the image plusses of LCD projectors. If resulting picture quality is crucial to you, then the answer is a no-brainer. Take an LCD projector! LCD projectors will constantly show bright, colourful images with fewer image imperfections. If you want to find out more about LCD technology in more detail, have a look at this tremendous resource website: Explore 3LCD. If you have any persisting questions, go to Projector Central and send me an email.

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