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The common question that is asked when looking for a new projector for the home, office, or classroom is: should I get an LCD projector or a DLP projector? LCD, an acronym for ‘liquid crystal device’ and DLP, an acronym for ‘digital light processing’ are the two most popular projector imaging technologies. With so many company brands and different types available, it can be confusing for the buyer to make a decision between both technologies. The simple fact of the matter is that LCD projectors offer better image quality and colour accuracy. The next part of this article will tell you why DLP projectors struggle with creating a comparable level of image quality.

It’s like a set of blinds in your household covering your bedroom window. By a twist of a rod you can turn the shutters open or closed, according to whether you want to let light in or not. And that is exactly how an LCD projector works. Each pixel operates like its own shutter on a set of blinds to either shine light through or to block it. DLP on the other hand is constructed of millions of microscopic mirrors or ‘pixel elements’ as the pros 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 is turned on to when the content reaches your screen is vitally significant for image quality, brightness and colour accuracy. LCD projectors process white light from the lamp by dividing it into red, blue and green components, by three mirrors which transfer the coloured light to 3 individual LCD panels. The 3 LCD panels form the elements of the image by switching each pixel on and off. The pixels are then projected in a glass prism to create the projector image. Something to understad about LCD projectors is that all three colours are delivered onto your projector screen all at the same time. The way a DLP projector operates is vastly different and even the final product of how an image comes out is not the same. With DLP, white light from the lamp is sent through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of forming an image creates a sequence of red, blue and green light. The millions of micro mirrors mentioned 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 pull together each coloured element of the image into the single full image. With LCD projectors, all colours are available all the time to form high brightness and great colour accuracy. In DLP, just one colour is available at a time, resulting in lower colour brightness and accuracy. Some DLP designers have placed a white segment into the colour wheel to improve brightness overall, but this also lessens colour accuracy.

I hear in forums all the time that DLP offers a higher contrast ratio and thus must be superior. For those who are unaware, 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 offer high contrast specifications in comparison to many LCD projectors. At a glance, this can seem to be a plus, however, in the real world, the true black level is determined by the ambient light in the room when the projector is being utilised. Do not be hoodwinked by contrast specifications on websites and in brochures.

When the content you plan to view includes moving images, DLP projection technology also has image errors, or ‘artifacts’. The most common artifact that a DLP projector forms 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 downside because all colours are sent with the others. DLP designers have created 3DLP solutions using 3 chips to fix the colour break up artifacts, but the expense of these projectors make them not practical for most businesses and consumers.

Another point of difference between LCD and DLP is how they match the balance for the refractive qualities of light. Jump back to high school science, and remember how various colours of light refract different amounts when projected through the same lens. The problem 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 not the same and refract light in a different way. Generally with a DLP projector, an extra yellow colour will show above and an extra blue will come up below an image as simple as a straight black line. In manufacturing LCD projectors can be set to reduce these effects on the projected image, as each colour is directed on its own LCD panels.

The isolated real plus (excluding price) with picking a DLP projector is its smaller overall size and weight. However, this is only relevant for transporting the device and cannot be traded off against the image advantages of LCD projectors. If the result of the picture quality is important to you, then the answer is no-brainer. Take an LCD projector! LCD projectors will always make bright, colourful images with fewer image mistakes. If you wish to ask more about LCD technology in more detail, see this tremendous resource website: Explore 3LCD. If you have any other questions, get onto Projector Central and send me an email.

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