So you’ve weighed it all up and you’ve come to the conclusion that the way to really bring that true big-screen home cinema experience to life is to swap the TV for a projector.

Now all you have to do is decide which kind of projector you should get; DLP or LCD.

First a short introduction (with the minimum of jargon)

So what’s LCD and DLP, you may be asking? And more to the point, what’s the difference? In a nutshell, it’s this:

LCD (liquid crystal display) projectors contain three separate LCD glass panels, one each for the red, green, and blue components of the video signal. (Don’t be confused by references you may see to 3LCD. It’s just a bit of a marketing blurb to distinguish the LCD technology found in digital projectors from the more common direct view LCD displays found in TV’s and laptops. In truth, whether it says 3LCD or LCD, it’s the same thing.)

DLP (digital light processing) works quite differently. In most DLP projectors, particularly at the affordable end of the market, to define colour, a colour wheel is used that contains (at minimum) a red, green, and blue filter. This wheel spins in the light path between the lamp and the DLP chip and alternates the colour of the light hitting the chip from red to green to blue

Which is best?

Both systems have advantages over the other, and they both have limitations. 

For professional home entertainment installers like me, there’s a lot of work to do to spec and select the one that best suits the client’s needs, budget and home environment. 

For everyone else, there’s one simple question: “Which should I get?”

And the answer is … that depends. On quite a lot of factors; where it’s going, how big or bright the room is, what you’re going to be watching, your budget, and so on.

So .. how much do you want to spend?

In the low to mid market, LCD projectors tend to offer more for the money, both on terms of image quality and extra features. But in the mid to top end, DLP projectors typically have the edge.

How long do you want it to last?

There’s a generally held view that LCD projectors have a shorter lifespan (however there’s no good independent data to back it up, and no-one’s prepared to say how much shorter).

This is because the organic compounds used in most LCD panels are expected to degrade over long periods of time leading to a discoloration of the image and a reduction in contrast. The only way to fix it is to replace the damaged LCD panel, which is typically cost-prohibitive – you’re normally better off buying a new projector. There’s no evidence of this happening with DLP projectors.

Also, LCD projectors use three imaging devices, so they must all be aligned perfectly so that the red, green, and blue information for each pixel is in convergence. Over time, these three device systems can slip out of alignment. 

The DLP design has only one imaging chip, so these convergence problems don't exist, as there’s nothing to go out of alignment.

Lastly, unlike LCD projectors, DLP projectors often have sealed chips, eliminating the possibility of a dust particle alighting on the imaging plane, which could create a spot on the projected image. They also don’t need air filters, so there’s less maintenance.

Where are you planning to put it?

In general, DLP projectors are smaller than their LCD counterparts – that may be an issue if space is limited.

However, LCD projectors often feature zoom lenses and extensive vertical and horizontal lens shift (the ability to move the lens within the projector housing to enable you align the projector with the screen). So they’re relatively easy to install just about anywhere.  

By comparison, DLP projectors usually have short zooms with little or no lens shift. Which means they usually need to be ceiling mounted, with the extra cost of a ceiling mount and long run video cables. Unless you’re having a major home installation done anyway, you may not want the long with the mess and potential inconvenience of having to run cables through walls and ceilings.

What sort of picture do you prefer?

DLP technology is considered to offer a more ‘film-like experience’. And though both technologies have made significant advances recently, the generally held view is that DLP offers better contrast, and richer shadow detail.

LCD technology, on the other hand, tends to produce more saturated colours and sharper images, though much of that sharpness is down to their more distinct pixel structure, which can sometimes mean that the pixels themselves are more visible than with a DLP projector (sometimes called the ‘screen-door’ effect).

How big is the room?

One of the goals of a good home cinema installation is that the projector’s pixel structure should be invisible at your normal seating distance. 

This is an area where DLP projectors have a distinct advantage over LCD projectors, enabling you to sit between 25 and 40% closer to the screen – ideal for those of us who like a big picture, but don’t have a huge room to watch it in.

How light is the room?

LCD home cinema projectors are typically brighter than their DLP counterparts, often, significantly so. 

So if your home cinema or video installation is in a room with some ambient light, or if you’re more likely to be using it for TV, sports, computers or gaming than for watching the latest Hollywood blockbusters, LCD projectors have a significant edge in brightness, particularly in low-to mid budget models

How sensitive are your eyes?

A DLP projector’s colour wheels can produce an effect called rainbow artifacts. They’re momentary flashes of banded colour that look like rainbows and are caused by the ‘strobing’ effect of the colour wheel as the light hitting the chip changes rapidly from, say, blue to red to green and back.

They occur at random, and they only last for an instant. The advances in DLP technology and the speed of the colour wheels in most current home cinema projectors mean that it’s only really an issue on lower-end DLP projectors, and even then, it only affects a minority of people whose eyes are sensitive enough to see it. But if you’re one of them it can be distracting enough not just to spoil your enjoyment of a movie, but to make you wish you’d gone for an LCD printer instead. (As they always deliver a constant red, green, and blue image simultaneously, they do not create rainbow artifacts.)

And the winner is…

You, actually.

As the competing technologies for market share, each is innovating at a serious rate in an effort to stay a step ahead of the competition.

Both DLP and LCD projectors are much better than they were even a few years ago. Overall picture quality has improved, with significant increases in contrast, resolution, and colour performance. 

And at the same time as the differences between the two technologies becomes increasingly less important, prices of both have dropped like a stone, with systems that once were available only to the wealthy now coming within the budget of the average home cinema enthusiast.

So the good news is that whichever choice you make, while it’s less likely to be significantly better than the alternative option, it will be a whole lot better than either system used to be.