Australian Content Blog

The most typical question that is asked when acquiring 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, short for ‘digital light processing’ are the two top projector imaging technologies. With so many different brands and types available, it can be confusing for clients to make a decision between these technologies. The simple fact of the matter is that LCD projectors have far better image quality and colour accuracy. The next paragraph tells you why DLP projectors struggle with reproducing the same rate of image quality.

Think of a set of blinds in your room for your bedroom window. By pulling a rod you can make the shutters open or closed, depending on if you want to let light in or not. And this is exactly how an LCD projector works. Each pixel functions like an individual 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 professionals 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 vitally significant to image quality, brightness and colour accuracy. LCD projectors project white light from the lamp by splitting 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 processing each pixel on and off. The pixels are then simultaneously processed in a glass prism to form the projector image. Something important to understad about LCD projectors is that all three colours are delivered onto your screen simultaneously. The way a DLP projector works is widely 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 way of forming an image creates a sequence of red, blue and green light. The millions of micro mirrors as mentioned above reflect the coloured light on the pixels to create the image elements. The elements of the image are projected in sequence on the screen, one colour at a time. The viewer’s eyes will then put together each coloured element of the image into a total image. From LCD projectors, all colours are available all the time to offer high brightness and fantastic colour accuracy. In DLP, only one colour is available at once, causing lower colour brightness and accuracy. Some designers have added a white segment in the colour wheel to improve all over brightness, but this goes and damages colour accuracy.

I see in forums all the time that DLP has a higher contrast ratio and ergo must be superior. For those who don’t 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 technology is capable of. DLP projectors do possess high contrast specifications as compared to a majority of LCD projectors. Initially, this appears to be a plus, however, in truth, the true black level is determined by the ambient light in the room when the projector is in use. Do not be duped by contrast specifications on websites and in brochures.

When the content you want to see includes moving images, DLP projection technology can also have 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 projected. LCD projectors do not have this characteristic because all the colours are processed with the others. DLP builders have created 3DLP solutions using 3 chips to solve the colour break up error, but the price of these projectors make them almost impossible for the majority of businesses and consumers.

Another point of difference between LCD and DLP is how they balance for the refractive qualities of light. Think back to high school science, and recall how different colours of light refract differing amounts when passing through the same lens. The problem with DLP projectors is that they utilise the one same panel for the same lens to project Red, Blue and Green. All 3 colours are different and refract light differently. Most of the time with a DLP projector, some extra yellow colour will come up above and some extra blue will show below something as simple as a straight black line. In building LCD projectors can be adapted to reduce these effects on the projected image, because each colour is projected on a separate LCD panels.

The only veritable buy point (excluding price) with deciding on a DLP projector is its overall smaller size and weight. However, this is only relevant for transport and has to be traded off against the image plusses of LCD projectors. If the result of the picture quality is vital to you, then the solution is a no-brainer. Choose an LCD projector! LCD projectors will consistently make bright, colourful images with fewer image imperfections. If you wish to ask more about LCD technology in more detail, have a look at this spectacular resource website: Explore 3LCD. If you have any additional questions, visit Projector Central and send me an email.

Jonathan King is the sales and marketing manager with Projector Central, Australia’s number one online store for projectors. Brisbane-based, Projector Central has been serving Australia for 15 years. For data projectors in Brisbane and Interactive Whiteboards, contact Projector Central today.