When it comes to projector technology, there are three main competing technologies, each with their own distinct set of advantages and disadvantages. They are:
- DLP (Digital Light Processing): DLP projectors first appeared in the 80s and rely on a DLP chip, made up of over 2 million tiny mirrors, each less than one-fifth the width of a human hair. Each mirror moves independently to create a light or dark pixel. This information is then fed through a spinning colour wheel to another chip, which can create up to 25 trillion colours on the most advanced models. The image is then fed through the lens and out onto your projection screen.
The advantages of such a system relate primarily to maintenance, requiring less maintenance than LCD projectors thanks to a filter-free and sealed chip design. However, most DLP projectors aren’t compatible with zoom lenses or lens shift functions, making them best suited to smaller environments rather than expansive screen set ups.
- LCD (Light Crystal Display): LCD projectors use the same technology found in TVs, tablets and smartphones to create projected images. Most LCD projectors use 3 LCD technology, which combines three liquid crystal displays to make your image. It begins with a light source providing a beam of white light. This light is passed to three mirrors which are shaped to only reflect a certain wavelength of light (red, green and blue). Each beam of coloured light then hits an LCD panel, which created an electrical signal that tells it how to arrange the pixels in the display to arrange in order to create your image. These images then combine in a prism to create a single image.
The advantages of LCD technology relate most commonly to cost. LCD projectors tend to be cheaper than their DLP or LED counterparts and are very efficient. They’re also less affected by colour and motion issues. On the downside, LCD displays are less capable at creating black levels and have worse contrast performance.
- LED (Light Emitting Diode): LED projectors replace the mirrors and colour wheel of the DLP projector with LEDs coloured in red, blue and green, which then shine directly on the DMD chip and are fed to the lens to create the image displayed.
LED projectors have a much longer lifespan than competing projector lamps, rated between 10,000 and 20,000 hours of continuous usage, up to 10 times more than other projector lamps. Because LEDs use very little energy and produce almost no heat, you’ll also enjoy lower running costs and almost no noise from an LED projector. The downside of LED projectors is that they cost more than competing technologies.
Other projector jargon
Alongside the major projection types, you’ll also encounter other phrases. Here’s a few of the major ones:
- Lumens: A lumen is a measurement of brightness, so more lumens equal a brighter light (or image, in the case of projectors). For reference, a 100-watt bulb would produce about 1,600 lumens. When shopping for a projector, keep in mind that the higher the quoted lumen levels, the better the projector will perform in conditions with ambient light.
- Short-Throw: Typically, projectors are situated 8-10 feet away from the surface they’re projecting on to. However, not everyone has the space to fit a projector that far away from their projecting surface. That’s where short-throw projectors come in. They use clever mirror arrays to throw a large image with very little run up. They can be fitted either above or below the screen, depending on the model.
- Widescreen: Widescreen projectors are capable of throwing an image in a widescreen format, typically 16/9. This means you’ll see less letterboxing when watching videos and enjoy a display resolution similar to that of your computer.
- 4/3: Projectors that are described as having a 4/3 resolution are only capable of displaying an almost square 4/3 aspect ratio, which is what many projector screens and interactive whiteboards are designed for.
- Contrast Ratio: A contract ratio is the luminance of the brightest colour (white) to that of the darkest colour (black) that the system is capable of producing. A typical contrast ratio will look something like 13,000:1. The higher the number on the left, the greater the range between light and dark the projector can produce.