One of the most popular blogs on the Rapallo site is the one about projector technology (DLP, LCD, LCoS).
A lot of noise is made about the rise, development, benefit and cost of 4K projector technology. But projector bulb technology (LED, Laser and traditional lamps) and display technology are the bones of a home theatre projector and should not be forgotten in making a choice for your new home theatre projector.
Once you start digging, acronyms start flying: DLP, 3LCD, LCoS. Different technologies have implications on performance, common issues and cost, so it’s time to dust off the whole LCD vs DLP vs LCoS argument.
Let’s have a look at what’s what first.
DLP (Digital Light Processing) is a commercial name for a display technology from Texas Instruments (TI) named a DMD chip. The technology is based on the use of millions of tiny mirrors, each representing a pixel, that is either turned ‘on’ (reflecting light) or ‘off’ (not reflecting light).
It’s the preferred technology of commercial cinema’s, although there are differences in that the commercial projectors use 3 chips while home theatre versions typically rely on a single chip and a spinning wheel with colour filters. The big advantage of the DLP technology is that he DLP chip minimizes gaps between pixels creating a seamless picture with pixilation that is less visible than with a 3LCD Projector.
Image from Optoma
DLP projectors used to have a reputation of providing good native contrast (and thus great black levels). Recently the technology has remained stagnant while both 3LCD and LCoS have made progress in the contrast ratio department, leaving DLP projectors to fall behind both other technologies in the lower price projectors.
For home theatre use, DLP’s tend to be lighter and smaller in size, which can be a great advantage to some people.
Another advantage of DLP’s is the fact that the technology in itself is faster than 3LCD or LCoS chips. This is a big bonus if you want to use your projector for gaming.
In the past, higher price brackets DLP projectors using 3 chip DLP’s for home theatre use were available. This is no longer the case. That said, we find recent home theatre DLP projectors have much improved in overall viewing experince in the past few years, especially the UHD4K DLP projectors who manage HDR really well, are now a viable option to consider, in our opinion.
BenQ, Optoma and Viewsonic are the home theatre projector brands that rely on this technology and currently offer the cheapest options available in the home theatre projector market. Panasonic also has some options available. JVC joined the DLP market last year with their JVC LX-UH1 projector. It is slightly more expensive than its peers, but it also comes with some extra features (like a better lens shift).
Stands for Liquid Crystal Display and is an overall term used for all projectors using LCD technology. The technology is fairly similar to the technology used in televisions.
Most LCD projectors are 3LCD projectors, which is actually a copyright name. Unlike DLP home theatre projectors that work with a spinning wheel; LCD’s have no moving parts (solid state).
3LCD technology uses 3 separate LCD panels: one for red, one for green and one for blue. Light from the projector lamp is separated into RGB with a set of dichroic mirrors. The three light beams (RGB) are passed through separate LCDs and recombined to project a colour image.
Image from Visionsolutionworks
Pricewise, they tend to come with more features such as lens shift and wide range zoom lens compared like for like with DLP’s, which can make projector placement a much easier exercise.
Popular 3LCD home theatre brands are most Epson and some previous Panasonic projectors (Panasonic has retreated from the home theatre projector market in recent years).
LCoS stands for Liquid Crystal on Silicon and is a variation on the LCD projector technology. It is different in that LCoS is a reflective panel rather than transmissive (light passes through it) used by the 3LCD technology.
LCoS projectors are best known for the least visible pixel structure and accurate performance. It wasn’t always the case, but these days LCoS projectors outperform both 3LCD and single chip DLP projectors when it comes to contrast ratio and black levels. The ‘but’ is: they also tend to be the more expensive option.
Other factors to consider:
Technologies like dynamic irises were developed to offset the disadvantages that used to come with 3LCD projectors when it came to contrast ratio.
Dynamic irises close to dim the image on dark scenes, and remain open to keep bright scenes bright. This somewhat improves the apparent contrast ratio even if the native contrast ratio is already pretty good.
These days, dynamic irises can be found on all 3 technologies. JVC’s LCoS projectors are the exception. The reason for that being that they have an excellent native contrast ratio as it is. (As far as we can tell, this is still the case for the new neative 4K JVC projectors.)
Also, sometimes the opening and closing of the dynamic lens is noticeable. That said, you can turn the auto iris off if you don’t like the result.
We don’t want to spend any time discussing light sources in this blog, but as we mentioned in the intro, whether your projector uses an LED, a laser or a hybrid lamp has considerable consequences on cost and how your projector performs, both short term as well as longer term. We have previously covered this in a blog so we like to refer you to it here.
Same goes for 4K projectors if you choose to go down that path. Our previous blog having a go at that topic is here.
Some common projector issues to take into account when making your decision:
DLP projectors claim a sealed light path – that is, dust cannot get into the system to end up on the DLP chip, or other surfaces in the light path. This is also true for most LCoS projectors. 3LCD, however is not sealed, that is air does blow past the panels, and dust landing on them, can cause a dust blob, that can be visible in dark scenes. Fortunately dust blobs are not a common problem, but worth mentioning (most – if not all), 3LCD manufacturers will treat a visible dust blob, as a warranty issue, and clean the projector under warranty.
or the softening of the image whenever there’s motion, can be 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. To compensate, many LCD and LCoS projectors tend to have a higher refresh rates. On top of that, Sony introduced Motionflow to their projectors, targeting the gaming and sports viewing market. For JVC projectors a similar feature is called ‘Motion Enhance’. The obvious downside is the price-tag of these projectors compared to the DLP’s. But there’s more criticism.
At the end of 2018, Tom Cruise got a lot of attention speaking out against ‘motion smoothing’ or ‘Frame interpolation’ used on TV’s (but the technology is basically the same as Sony’s Motionflow and JVC’s ‘Clear Motion Drive’ on projectors). Cruise is joined in his battle by Christopher McQuarrie. His beef has to do with “the unfortunate effect that it makes most movies look like they were shot on high-speed video rather than film,” according to Cruise. “This is sometimes referred to as the ‘soap-opera effect’.” He recommends turning the feature off and we have to agree with him one this one, unless you are actually using the projector for gaming.
In short, motion smoothing is a process that adds extra frames between existing frames to make motion look smoother. The interpolation process uses the two existing frames as a start and end point, and then essentially guesses the extra frames in-between.
is an artefact where it seems bright objects (especially on a dark background) appear to have trails of multi-coloured light. It’s the single-chip DLP projectors that suffer from this. Let’s explain, because of the single chip DLP technology works, at any given fraction of a second, there’s just one colour on the screen. This is done fast enough that your brain combines it into a full-colour image…mostly. Some people are susceptible to “rainbows,” where their brain registers the sequential colour. It looks like a rainbow smear, and it’s especially noticeable if you move your eyes rapidly around the screen.
Our experience is that it’s rare for people to notice or be bothered by rainbow effect, but you want to be certain that you’re not the one exception when making the purchase.
So which one?
Different people need different things and have different budgets. It is important to point out that all 3 technologies have great projectors. A lot comes down to your situation, how you want to use your projector and your budget.
If your budget is limited you will almost automatically end up with a choice between a DLP (small and light and great for gaming) or 3LCD projector (more features at the same price point).
If your budget reaches around the $5,000 to $10,000, you can’t beat the LCoS projectors for overall performance.
Over that budget, the world is your oyster with good options from all 3 technologies. With a budget just under $10,000 you are throwing 4K considerations into the equation as well.
Happy projector shopping! Give us a ring to organise your demo for an informed decision.
Sources: Cnet, Projector Central, Sony, JVC, Optoma, Benq, Epson, Home theater reviews