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The most common question customers ask when acquiring a new projector for the home, office, or classroom is: would I purchase an LCD projector or a DLP projector? LCD, which stands for ‘liquid crystal device’ and DLP, an acronym for ‘digital light processing’ are the two most common projector imaging technologies. With so many different brands and types available, it can be challenging for consumers to make a decision between both technologies. The fact is that LCD projectors provide superior image quality and colour accuracy. The next paragraph will tell you why DLP projectors struggle with bringing up the same standard of image quality.

It’s like a set of blinds in your house for your bedroom window. By pulling a rod you can have the shutters open or closed, depending on whether you want to let light in or not. This is exactly how an LCD projector behaves. Each pixel functions like a single shutter on a set of blinds to either allow 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 works to either reflect light or block it.

How the light source is processed from when the projector switches on to when the content reaches your screen is vitally important in regard to image quality, brightness and colour accuracy. LCD projectors project white light from the lamp by cutting 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 shining each pixel on and off. The pixels are then simultaneously processed in a glass prism to send the projector image. A point to realise about LCD projectors is that all three colours are directed onto your projected surface simultaneously. The way a DLP projector runs is totally different and even the way an image comes out is not the same. With DLP, white light from the lamp is directed through a spinning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This way of making an image casts 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 projected 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 whole image. In LCD projectors, all colours are available all the time to create top brightness and superb colour accuracy. In DLP, only one colour is available at a time, and so causing lower colour brightness and accuracy. Some manufacturers have included a white segment into the colour wheel to improve brightness overall, but this also lessens colour accuracy.

I find in forums all the time that DLP offers a higher contrast ratio and ergo must be better quality. 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 projector is capable of producing. DLP projectors do possess high contrast specifications compared to the majority of LCD projectors. Initially, this must be an advantage, however, in truth, the true black level is determined by the ambient light in the room in which the projector is in use. Do not be tricked by contrast specifications on websites and in brochures.

When the content you want to bring to life needs moving images, DLP projection technology can also create image errors, or ‘artifacts’. The most typical artifact that a DLP projector displays with moving images is colour break up. Colour break up is inherent in DLP systems because moving images change position between the time red, blue and green colours are pulled up. LCD projectors do not have this characteristic because the colours are projected at once. DLP manufacturers have created 3DLP solutions using 3 chips to answer the colour break up issue, but the cost of these projectors make them almost impossible for many businesses and consumers.

Another variance between LCD and DLP is how they match the balance for the refractive qualities of light. Remember back to high school science, and they taught you how the various colours of light refract different amounts when passing through the same lens. The downfall 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 at different levels. Often with a DLP projector, a superfluous yellow colour will show above and some blue will be projected below something as simple as a single black line. In building LCD projectors can be fixed to minimize these effects on the projected image, as each colour is processed on isolated LCD panels.

The sole real plus (excluding price) with taking a DLP projector is its smaller size and weight. However, this is only relevant in regard to transporting the device and cannot be traded off against the image plusses of LCD projectors. If the result of the picture quality is crucial to you, then the answer is easy. Go with an LCD projector! LCD projectors will always create bright, colourful images with fewer image mistakes. If you want to find out more about LCD technology in more detail, check out this fantastic 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 number one online retailer 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.