Buying Guide: Types of Video Projectors

Video projectors use one of three main technologies: DLP, LCD, or Liquid-Crystal on Silicon (LCoS). Each technology offers its own distinct advantages and disadvantages. Depending on the type of content you want your projector to display, and the setup of your room, one of them might make more sense than the others.

DLP (Digital Light Processing)
DLP projectors contain an array of microscopic mirrors that tilt either toward the light source in the projector or away from it to create a light or dark pixel on the projection screen. DLP projectors are available in single-chip and three-chip versions. Single-chip versions start at under $1,000, while three-chip models start at around $10,000.

Single-chip DLP offers the sharpest image you can usually find in a home projector. While all other types of projectors use three chips, also called “panels” (one for each primary color in an image), DLP projectors use a single chip. This means there are no panel alignment problems and the image is razor sharp. To accomplish this, a single-chip DLP projector uses a color wheel that rotates between the three primary colors. For many people this is fine, but some users might notice a “rainbow effect.” A rainbow effect breaks up the image into separate red, green, and blue images. For example, if there is white text on the screen and you move your head, you will see the same text in red, blue, and green. Some people never see these multiple images; but others do, so be sure to watch a movie on a DLP projector before buying one.

Three-chip DLP projectors do not suffer from this rainbow effect because they use a DLP chip for each color instead of a color wheel. The drawback is that getting all three panels in perfect alignment is harder and therefore requires a more complex and expensive design. Three-chip DLP projectors are often what movie theaters use. They are capable of producing bigger, brighter images than other projector technologies. They are also available in resolutions up to 4K, and have the ability to produce more colors than other types of projectors.

DLP projectors are usually the best for watching 3D movies. Since the mirrors turn completely on or off, 3D is free of the faint double images that LCD and LCoS projectors can sometimes produce. This instant on/off ability also makes them a good choice for sports with its fast action. Video games are another good area for DLP projectors because of their fast response and lower lag times.

DLP Advantages

Sharpness
3D
Fast motion
Brightness

DLP Disadvantages

Muddy rendering of black colors
Limited placement flexibility
Possible rainbow effect

LCoS (Liquid Crystal on Silicon)
Like an LCD projector, LCoS projectors shine light through a panel to create an image. Unlike LCD projectors which shine a light through a single LCD panel, the light from a LCoS projector reflects off three individual LCoS panels, which are then combined to produce the image. By reflecting the light off the panel instead of shining light through it, LCoS projectors offer the darkest black levels and contrast ratios of any technology. Better black levels make the film more immersive when viewed in a dark room. Plus, the letterbox bars on CinemaScope-format movies disappear and shadows look much better. Darker blacks also help increase the contrast ratio, which gives the image more pop. However, LCoS projectors usually cannot offer the same brightness levels of DLP and LCD projectors (which makes these two types of projectors ideal for rooms where there is a high degree of ambient light, or if you simply like to watch video with the lights on).

Because LCoS projectors usually offer lower levels of light output, they often don’t work well when paired with gigantic screens. For screens measuring less than 130 inches diagonally, they are able to produce enough light to fill the entire screen; anything larger and it’s best to use a brighter projector. They also exhibit more image blurring on fast-moving images than DLP and some LCD projectors. For film, this isn’t an issue, but it makes them problematic when watching sports and 3D content. For watching films in a dedicated room, they offer the best blacks and contrast ratios currently available. LCoS projectors start at around $2,500 and top out at $12,000 for 1080p and $25,000 for 4K.

LCoS Advantages

Dark blacks
High contrast ratio
Film-like images

LCoS Disadvantages

Low maximum brightness
Noisy 3D
Blurry fast-motion scenes
Expensive

LCD (Liquid Crystal Display)
LCD projectors fall right in the middle of DLP and LCoS projectors. They aren’t as bright as DLP projectors, but they are usually brighter than a LCoS projector. They don’t produce the deep blacks that LCoS projectors do, but they are better at it than DLP projectors. Motion is not as sharp and fast as what a DLP projector can produce, but motion from an LCD projector trumps that of a LCoS projector. 3D images produced by an LCD projector can be less accurate (faint double images) than 3D images produced by a DLP projector, but an LCD projector can outperform a LCoS projector due to its ability to produce bright images. LCD projectors are affordable, starting at the same price as a single-chip DLP projector. At the high-end, an LCD projectors costs just a few thousand dollars.

LCD Advantages

High brightness
Good rendering of blacks
Good handling of motion

LCD Disadvantages

Noisy dynamic iris
No LED or laser light engine options

Most of the above projectors, no matter which technology they employ, use high-powered light bulbs, called lamps, to produce the light that forms the images on the screen. These bulbs start at $200 and often last for 2,000 to 5,000 hours, depending on usage. If you watch a projector in the Eco mode, which usually produces more than enough light for a dedicated theater room, the bulb will last much longer. If you watch a lot of 3D movies or in a room with a lot of natural and/or ambient light, the bulb will burn out faster. Lamps also dim over time so even if the lamp life is 5,000 hours, you may find that after 2,000 to 3,000 hours of use it is dim enough to warrant buying a new bulb.

LED and Laser
If you’d rather not deal with the maintenance of replacing bulbs in your projector, consider an LED or laser video projector. The LEDs used in a projector boast much longer lifespans (20,000 hours or more) than traditional projector bulbs. There are other benefits: Red, blue, and green LEDs replace the projector’s lamp, which means no color wheel is necessary (as it is with a traditional DLP projector). Minus the color wheel, the rainbow effect is eliminated, and so is the noise generated by the movement of the wheel. LED projectors, like the Optoma HD91+, start at around $4,000 and quickly rise from there.

LED Advantages

20,000+ hour lifespan
No color wheel
Fast to power up and down
Quiet operation
Energy efficient
Large color gamut

LED Disadvantages

Cannot replace the light engine if it eventually dies
Lower maximum brightness than bulb-based projectors
Expensive

Laser projectors are also relatively new. As the name implies, this type of projector uses lasers with a DLP or LCoS engine to produce their images. Just like LEDs, lasers last for 20,000 to 30,000 hours and do not dim over time. Lasers are also fast so they can turn off and on almost instantly to produce darker blacks than a traditional lamp can. Once a laser projector dies, you resurrect it by putting in a new lamp. However, with 30,000 hours of life you could use a laser projector six hours a day for 14 years before it would quit. Expect to pay at least $6,000 (the Epson LS9600e) for a laser projector.

Laser Advantages