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The most typical question asked when acquiring a new projector for the home, office, or classroom is: do I buy an LCD projector or a DLP projector? LCD, short for ‘liquid crystal device’ and DLP, standing for ‘digital light processing’ are the two commonplace projector imaging technologies. With so many different brands and types available, it can be overwhelming for the buyer to make a decision between these technologies. It comes down to the fact that LCD projectors offer better image quality and colour accuracy. The article below will tell you why DLP projectors struggle with creating a similar standard of image quality.

Visualise a set of blinds in your house over 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 operates. Each pixel functions like its own shutter on a set of blinds to either pass 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 is turned on to when the picture reaches your screen is extremely significant for 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 send the coloured light to 3 individual LCD panels. The 3 LCD panels create the elements of the image by switching each pixel on and off. The pixels are then projected in a glass prism to send the projector image. An important point to know about LCD projectors is that all three colours are directed onto your wall at the same time. The way a DLP projector runs is widely different and even the final product of how an image looks is not the same. With DLP, white light from the lamp is processed through a turning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of making an image requires 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 combine each coloured element of the image into a total image. From LCD projectors, all colours are available all the time to create the top level of brightness and spectacular colour accuracy. In DLP, only one colour is available at once, resulting in lower colour brightness and accuracy. Some DLP designers have added a white segment into the colour wheel to improve overall brightness, but this goes and lessens colour accuracy.

I find in forums all the time that DLP provides a higher contrast ratio and ergo 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. DLP projectors do provide high contrast specifications as compared to the majority of LCD projectors. Initially, this can seem to be a benefit, however, in truth, the true black level is determined by the ambient light in the room in which the projector is utilised. Do not be hoodwinked by contrast specifications on websites and in brochures.

When the content you are trying to bring to life needs moving images, DLP projection technology also has image errors, 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 change between the time red, blue and green colours are shone. LCD projectors do not have this downside because all the colours are delivered with the others. DLP developers have created 3DLP solutions using 3 chips to fix the colour break up error, but the price tag of these projectors make them almost impossible for the large part of businesses and consumers.

Another differentiation between LCD and DLP is how they balance for the refractive qualities of light. Think back to high school science, and recall when they taught you how different colours of light refract varied amounts when shone through the same lens. The downside with DLP projectors is that they use the one same panel for the same lens to project Red, Blue and Green. All 3 colours are different and refract light differently. Often with a DLP projector, a superfluous yellow colour will show above and some blue will come through below an image as simple as a straight black line. In building LCD projectors can be adjusted to minimize these effects on the projected image, because each colour is projected on separate LCD panels.

The only true buy point (excluding price) with choosing a DLP projector is its overall smaller size and weight. However, this is only relevant to mobility and has to be traded off against the image superiority of LCD projectors. If overall picture quality is vital to you, then the answer is easy. Go with an LCD projector! LCD projectors will constantly produce bright, colourful images with fewer image imperfections. If you wish to know more about LCD technology in more detail, have a gander at this tremendous resource website: Explore 3LCD. If you have any persisting questions, jump onto Projector Central and send me an email.

Jonathan King is the sales and marketing manager at Projector Central, Australia’s leading 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.