War of the projectors: DLP vs LCD vs LCoS

Projectors are awesome. Ultra-huge screen, reasonably low price. If we can get away with the other half’s approval for one, they are the bee’s knees for your home cinema.

A while back, Cnet published an excellent overview with the different projector technologies available.

In our experience the article covers one of the most often asked questions, when it comes to projector purchases. Since we honestly couldn’t say it any better ourselves, we used this article as a base and added some of our own remarks and experiences to it. Where we thought it needed an update, we added that as well.

 

To sum it up, there are three different technologies projectors used to create an image: DLP, LCD, and LCoS.

What’s the best? Let’s compare.

 

 

DLP, or digital light processing, uses tiny mirrors to reflect light toward the screen (an “on” pixel) or away (an “off” pixel). Most (less expensive) models use a color wheel -literally a spinning wheel with color filters – to create sequential color. Some high-end models use three DLP chips; one each for red, green, and blue. DLP projectors range in price from just under a thousand dollars to tens of thousands, and more. Most projectors in movie theaters use DLP. You can find models from Optoma, BenQ, Mitsubishi, and many others.

 

Rapallo note: For many users, a key advantage of DLP projectors is that in general, they are smaller and lighter than their LCD counterparts (That said, there are a few portable LCoS projectors available).

 

 

LCD, which stands for liquid crystal display, is very similar to the technology found in most TVs. LCD projectors use three liquid crystal panels, each tasked with creating an image using just one of the primary colors (red, green, and blue). All three are projected on the screen at once, so you see a full color image. LCD projectors range in price from just over a thousand to several thousand dollars, and are available from companies like Epson, Panasonic, and others.

 

 

LCoS, or liquid crystal on silicon, is sort of a hybrid between LCD and DLP. It uses liquid crystal chips with a mirrored backing. So they’re reflective, like DLP, but block light using liquid crystal, like LCDs. Sony and JVC are the primary manufacturers of LCoS projectors, which they call SXRD and D-ILA, respectively. LCoS projectors range in price from a few thousand dollars to a few models that are in the tens-of-thousands range.

 

What follows are generalizations.

The properties of each technology described are typical, but not universal. Each technology has positives and negatives, and there are good and bad projectors that use each technology.

 

 

OK, on to the good, the bad, and the pixels.

 

Contrast ratio

 

Winner: LCoS

Loser: DLP

Runner-up: LCD

 

Contrast ratio is the most important aspect of picture quality. It is the main determinant for how realistic an image looks. Consistently, JVC’s D-ILA projectors have the best contrast ratios of any display I measure over the course of a year. Better even than plasma. Sony’s SXRD comes in second.

LCDs have come a long way in recent years, and some now offer some excellent performance in their own right.

DLP, however, has not. Its native contrast ratio has changed little in the past few years, and has fallen behind LCD and LCoS.

Most projectors have an Auto Iris, which closes to dim the image on dark scenes, and remains open to keep bright scenes bright. While these do improve the apparent contrast ratio somewhat, the higher native contrast ratio of the LCoS projectors still looks better overall. Sometimes the opening and closing is noticeable, but you can turn the auto iris off if you don’t like the effect/result.

 

Black level

 

Winner: LCoS

Loser: DLP

Runner-up: LCD

 

I tie this in with contrast ratio. Both JVC and Sony models have a high native contrast ratio, offering deep blacks at the same time as bright whites. Projectors with an iris can do one or the other (and not at the same time).

 

Rapallo note: Our experience agrees with the findings of the guys from Cnet: LCos and LCD projectors seem to outperform the DLP’s. That said, we have the impression that black level is one of the area’s where constant progress is made. It definetely pays to check out individual reviews.

 

Light output (brightness)

 

Winner: LCD and DLP

Loser: LCoS

Runner-up: All?

 

This is a tough one, as light output varies a lot between projectors. Right now, the two brightest projectors I’ve tested were LCD and DLP. LCoS projectors tend not to be as bright as certain LCD and DLP projectors, but recent LCoS projectors offer more light output than any projector from just a few years ago, so I consider all “adequate” in this regard, with some being more adequate than others.

 

Rapallo note: In general, DLP projectors tend to suffer the most from ambient light, so this is definitely something to take into account depending on your personal situation.

That said, we just installed a Sony HW40ES demo model (LCoS) in our completely dark (no windows) showroom. Our four heads team started comparing the difference in light output between the new Sony projector and the Epson (LCD) or Panasonic (LCD) or Optoma (DLP) projectors in a similar price bracket and every single one of us found the difference in brightness to be absolutely minimal in these conditions.

 

Color

 

Winner: Draw

 

Color accuracy varies a lot per projector. I’ve reviewed projectors with accurate color from all technologies. Best to check reviews to see if the model you’re considering performs well in this regard.

 

Rapallo note: DLP projectors virtually have no color degradation and the only consumable part is a light source (lamp module or bulb).

There is a bit of a problem with LCD panels degradation, which causes yellow or green screen effect over extended periods of usage.

 

Motion blur

 

Winner: DLP

Loser: LCD and LCoS

 

Motion blur, or the softening of the image whenever there’s motion, is a problem with LCD and LCoS displays. Some people aren’t bothered by it, but others notice it. Side-by-side, a DLP projector will look sharper and more detailed during fast motion than an LCD or LCoS projector. This is not enough to offset DLP’s worse contrast ratio performance, though. Many LCD and LCoS projectors have higher refresh rates, just like many LCD TVs.

 

Rapallo note: We had a couple of teenagers over to have a go at some gaming on our demo models last week. We did a comparative test on some fast action motion. We had a look at our usual suspects: the the Optoma HD50, the Epson TW6600 and the Panasonic PTAE8000.  Our conclusion was that we could not see any difference in motion blur while gaming nor when we played some fast action movies (and nor could the customers during demo’s for that matter). I guess the conclusion is that the difference on paper between 20-odd milliseconds for the Optoma and 40-odd milliseconds on the Panasonic are pretty neglible and not visible at all.

 

Rainbows

 

Winners: LCD and LCoS

Loser: DLP

 

“Rainbows” are an artifact where it seems bright objects (especially on a dark background) appear to have trails of multicolored light. Three-chip projectors, like LCD, LCoS, and high-end DLP models, don’t have the rainbow artifact. Single-chip DLP projectors, however, create an image using “sequential” color. As in, at any given fraction of a second, there’s just one color on the screen. This is done fast enough that your brain combines it into a full-color image…mostly. Some people are susceptible to “rainbows,” where their brain registers the sequential color. It looks like a rainbow smear, and it’s especially noticeable if you move your eyes rapidly around the screen, or bright moving objects on a dark background (like streetlights). In all the years I’ve been reviewing DLP products, I’ve found that everyone falls into one of three categories:

 

People who can see rainbows and are bothered by them.

People who can see rainbows and are not bothered by them.

People who can’t see rainbows.

 

Most people fall in the latter two categories, but if you’re in the first, DLP isn’t right for you. With faster and faster color wheels, and the move toward LED and laser light sources, rainbows are much less apparent than they used to be.

Another option is three-chip DLP projectors, but these are much more expensive than the single-chip varieties, and still don’t have the contrast ratios of LCoS models.

 

Rapallo note: If you are keen on a single-chip DLP projector but are worried about the rainbow effect, we recommend to choose projector equipped with 4x or higher color wheel speed. Also, it always pays check out the projector viewing experience in a demo to make sure. We can always get a demo unit in if we have not got the one you are looking for in our demo room.

 

Convergence

 

Winner: Single-chip DLP

Loser: Three-chip DLP, LCD, LCoS

 

The chips that create an image in a projector are very small, and even tiny variations in the positions each chip can be visible on screen. These can look like colored edges to white objects or, worst case, a softness. Most three-chip projectors come with convergence adjustments (of varying amounts), but these can’t always totally eliminate convergence errors. Worse, it’s hard to tell from reviews if a projector has good or bad convergence, as it can vary on a per-unit level. That is, the one I review could be perfect, but yours got tossed off the back of a truck and is terrible. Single-chip DLP projectors, of course, don’t have convergence problems because there’s nothing to converge

 

Bottom line

 

As I said at the top of this piece, there are good and bad projectors based on each technology. That said, each technology has strengths and weaknesses, so knowing these going in can help you find the perfect projector.

 

Rapallo note: The article doesn’t discuss other important deciders that play in the purchase of a projector like fan noise, ease of set-up, lamp life, LED or laser, warranty, throw distance, additional bells and whistles that are pretty much individual to the projector model etc. rather than the technology. Combined with the fact that each technology produces projectors that undeniably deliver, it is really important to read up on different model reviews and ask for your individual demo. What works for you might not work for me. As mentioned before, we will get a demo unit in if we don’t have the one you are looking for in our demo room. We really want to make sure that your choice is the right one for you.

 

Personally, we are really, really looking forward to the release of the Optoma single chip LED 4K DLP later this year. Expectations are high, as previews have been consistently raving. This could be a game changer.

 

But back to our 3 technologies: DLP vs LCD (vs LCoS) wars are as old as the mass projector market exists, and still any person can find a projector which suits his or her needs best. Our own humble experience is that difference have become smaller and smaller over the years. Cost of light bulbs, longevity of lightbulbs, and brand loyalty seem to be more important than small technical differences. DLP seems to be the standard in professional cinema, but in home cinema LCD is still very strong. Maybe LCoS will be best of both worlds and prove to be the ultimate winner? What do you think?