Types of Projectors: LCD, DLP, and LCoS Explained

By Dylan Clayton
Last Updated April 16, 2021

If the time has come to choose a projector, it is easy to get bogged down by all the jargon and specifications. However, your choice is really dependent on two factors: viewing requirements and room size.

The first consideration are your viewing requirements; is it mostly for movie screenings, outdoor use, gaming, or professional presentation use?

The second factor is room size to ascertain whether you need a short-throw or long-throw projector.

Types of Projectors

There are three main types of projector, each categorized by the image projection mechanism. Liquid-crystal display, Digital Light Processing, and Liquid Crystal on Silicone devices have individual sets of specifications designed to suit particular applications and budgets.

Liquid-Crystal Display (LCD) Projectors

lcd projector prism
LCD Projector Prism

LCD projectors were once the go-to model, but as Digital Light Processing (DLP) and Liquid Crystal on Silicone LCoS gain popularity, fewer LCDs are sold.

They operate using three LCD glass panels that project the same image simultaneously. Light from a lamp or LED splits the light into red, blue, and green wavelengths using a series of angled dichroic mirrors.

Each beam hits a separate LCD panel producing three different colored variations of the same image.

Light from the panels combine and, using a prism, reproduces the image at the main lens.

They are the most light efficient of all types of projectors, emitting brighter images even with the identical lumen rating as their contemporaries.

The contrast ratio of an LCD model is good, higher than that of some DLP projectors. It is another factor that contributes to light, bright images. Its downfall comes in the darker ranges where shadows aren't as detailed as expected, and rich blacks are instead hazy grays.

Advantages of LCD

  • They are extremely light and power-efficient, consuming far less power than DLP projects and somewhat less than LCoS models.
  • Excellent color reproduction as there is no color wheel to reduce saturation, resulting in vibrant colors ideal for movies and videos.
  • No mechanical components mean there is less chance of anything going wrong with the projector.
  • 2000 – 4000 hours light source life-span.

Disadvantages of LCD

  • A lower brightness rating means they are best in darkened rooms or with low ambient lighting.
  • Require some maintenance; regular filter changes.
  • Their lower contrast ratio rating means they aren't best-suited to textual reproduction; so not the best choice for offices and schools.
  • Fixed amount of pixels that become more visible as the picture expands.

Digital Light Processing (DLP) Projectors

inside dlp projector
Inside DLP Projector

DLP projectors utilize a Digital Micro-mirror Device (DMD) that contains over one million of the tiniest mirrors imaginable. Each one sits on a hinge allowing it to reflect or block light from the screen. Each mirror represents a single pixel of the video.

The color comes from a spinning wheel that filters light from the lamp which, in turn, is reflected by the mirrors.

The most common type of DLP projector is known as the single-chip. Regularly found in home theaters, they are capable of full HD 16:9 aspect ratio and 1920 x 1080 pixel resolution (a must for front projections and large screens)

DLP projector images are sharp and very bright; They can reproduce 3D images to a very high standard. The contrast of black shades isn't always the best and can occasionally appear muddied.

Advantages of DLP

  • Relatively inexpensive.
  • Compact size and easy set-up.
  • DLP projectors have the best brightness ratings of all their competitors. They are ideal for rooms with moderate to high ambient lighting.
  • Immune from image burn-in (discoloration of areas on an electronic screen).
  • Require little maintenance as they don't contain a filter.
  • Their good contrast ratio projects crisp, realistic detail. They are well-suited to home movie theaters and offices.

Disadvantages of DLP

  • Less than perfect reproduction of shades of black
  • The only type of projector that produces rainbow artifacts; tiny rainbow-like reflections that a small number of viewers spot on the screen. The issue only occurs when the color wheel spins at a slower than usual speed.

Liquid Crystal on Silicone (LCoS)

lcos projector
LCoS Projector

LCoS projectors are a relatively new technology; they combine the best of LCD and DLP, resulting in a superb hybrid.

Like their LCD counterparts, they separate light into red, blue, and green components before directing it to LCD panels. Instead of passing through each one, the light reflects against the shiny LCoS surface behind, back through the cells.

The light source is typically a white lamp, but some models employ a blue laser with a yellow phosphor wheel as the light source.

Both styles behave in the same manner; the reflected light from the images combines in a prism and projects through the primary lens.

Advantages of LCoS

  • Expect movies and text documents in the highest level of detail and sharpness. The LCoS is the projector of choice for the highest-end home movie theaters and cinemas.
  • The hybrid technology provides the viewer with the most accurate cinematic experience. All colors and images are better and sharper than those of its rivals.

Disadvantages of LCoS

  • Most LCoS projectors only manage an average brightness rating. Although, some models are equal to their DLP counterparts, allowing for decent viewing in rooms with low to moderate ambient lighting.
  • They are the most expensive type of projector; usually worth the trade-off with their superior image quality.
  • They are heavy; not designed with portability or multi-room use in mind.

Factors to Consider in Projectors

Resolution

The clarity of an image directly relates to the number of pixels in a given area. The greater the number of pixels results in a more precise projection.

  • 4K projectors are typically 3840 x 2160 (8,294,400 pixels)
  • Full HD is typically 1920 x 1080 (2,073,600 pixels)

Keep in mind, viewing distance matters.

For example a screen size of 50 inches at a viewing distance of 15 feet. Resolutions of 4k, 1080p, 720p, and 480p are equivalent to the naked eye.

Contrast Ratio

The contrast ratio relates to the comparison between the whitest whites and the darkest darks in an image; Ambient light in a room affects the contrast on a screen.

The best projectors offer a ratio of at least 1000:1; the whitest areas are 1000 times brighter than the darkest areas.

Brightness

Measured in lumens (lm), the higher the lm rating, the brighter the projected image.

As a rule of thumb, in a dark room, such as a home movie theater with no ambient light, 1000lm is sufficient.

For an outdoor screen or a room with lots of flooded doors and window light, we recommend a projector with at least a 3000lm rating.

Throw Type

Short throw projectors suit small rooms as they only need to be 3-feet away from the projection screen.

Large throw projectors, the most common type, are best suited to large spaces as they operate from a distance of at least 6-feet.

Read More: The Difference Between Short Throw and Long Throw Projectors

Final Thoughts

The best type of projector is very much governed by your requirements and available budget.

If you plan on using it solely for screening movies, then an LCD model will suit your needs. DLP projectors are the most affordable type and are multi-purpose. LCoS projectors produce the best picture quality but at a greater cost.

All types of projectors suit differing budgets; a high-end DLP model projects better videos than a bargain-basement LCD model; it is all about finding the best trade-off.

References

Dylan Clayton
My passion for cinema resulted in a hobby for Home Theaters and the creation and ideation of this website. My goal for Home Theater Explained is to share my experiences with other Cinephiles in hopes that they too can improve their own setups.