Has UltraHD front projection just become affordable? Stephen Dawson finds out.
One of the great oddities in home entertainment these past few years has been the strange order in which UltraHD has rolled out. First there were displays, wanting of source devices able to really take advantage of them. But those displays were – expect for a few super large models by which their manufacturers could show their chops – regular sized TVs. Missing were front projectors, except for Sony’s very expensive lineup. Finally last year UltraHD Blu-ray discs and players arrived, but there was still the front projector hole.
The higher resolution is tailor-made for large screens, but still Sony’s $15,000+ offerings were all that was available. Until the close of the year when BenQ released its reasonably priced Ultra High Definition projector, the W11000.
What it is
The BenQ W11000 is the company’s current top-of-the-line home theatre projector. As is BenQ’s norm, it uses DLP technology. That is, there is one single Digital Micro-mirror Device. Colour is achieved by using a colour wheel which has colour filter windows and spins rapidly, admitting the light of one of the three colours in synchronisation with the activation of the pixels appropriate to that colour.
The DMD used in this projector does not natively offer the full UltraHD resolution of 3,840 pixels across by 2,160 pixels vertically. Instead it gets by with a panel resolution of 2,716 by 1,528 pixels and uses a process called XPR to increase the output resolution to the full number required for UltraHD.
This picture engine is housed in a large, heavy enclosure: nearly 15kg in weight and 565mm on the longest (front to back) dimension.
Some installation flexibility is provided by the optics: the zoom range is 1.5:1 and there is both horizontal and vertical lens shift available. Unlike some premium projectors, all adjustments are manual, not powered. Given that these are typically performed just once this really isn’t a significant negative.
BenQ specifies the throw ratio of the projector at 1.37 to 2.06 (depending on zoom range). Back calculating from the manual’s table relating screen size to projector distance, I determined the throw ratio at 1.36 to 2.03. In any case, for a 100” diagonal, the projector needs to be mounted at a range from 3m to 4.5m from the screen.
The maximum output is rated at 2,200 ANSI Lumens and a 240W lamp is employed.
BenQ has reduced the number of inputs. No more traditional composite or component video (nor S-Video, with which BenQ persisted longer than most). There’s still a D-SUB15 computer-style analogue input, but otherwise it’s HDMI only. One of the HDMI inputs supports signals up to 1080p, while the main one handles UltraHD – 3,840 by 2,160 at 50 and 60 frames per second. It does not support ‘true’ 4K – 4,096 by 2,160 pixels – a format that doesn’t appear in the home theatre context.
The UHD-capable HDMI input supports the all-important HDCP 2.2 copy protection scheme, required in order to play UltraHD Blu-ray.
The inputs and other connections are on the right hand side (looking from the front with the projector the right way up). There are also control options via RS-232C, Ethernet, an IR input and two 12V triggers.
XPR vs Pixel Shifting
Now, there’s a bit of engineering magic involved with this projector. Somehow it takes the 2,716 by 1,528 pixels of the digital micromirror device and produces 3,840 by 2,160 pixels output. And, yes, it really does this. Of course, as we’ll see, I watched a number of UltraHD Blu-ray movies. But I’m sufficiently aware of my perceptual limitations – likely shared with more people than would like to admit it – to not fully trust my eyes with regular program material. So I’ve developed various tests that allow positive confirmation that things do what they’re supposed to do.
In the case of UHD resolution, I have made a simple test pattern in which, in sections of the screen, white lines alternate with coloured ones or black ones. In each case, the width of the lines are one pixel at UHD resolutions. On a properly performing UHD display device, particularly when I’ve switched off some of the picture ‘improvement’ functions that more often reduce quality than improve it, each line is clearly reproduced.
And on this projector, each line was clearly reproduced, albeit sketched out not quite as clearly as with a UHD TV in which each output pixel is produced by a physical display pixel.
So how does BenQ do it? It’s actually a Texas Instruments technology (TI makes and owns DLP) called XPR for ‘eXpanded Pixel Resolution’. What this does is shift pixels diagonally using an ‘optical actuator’.
Haven’t we been here before? Haven’t there several brands of ‘4K-enhanced’ projectors around for a couple of years using some form of pixel shifting technology?
Indeed, and I’ve not been particularly impressed by them. Apart from anything else, they had a fundamental limitation due to pixel size. They were necessarily designed so that each pixel occupied almost the entire space of a cell in a 1,920 by 1,080 pixel grid. If they were significantly smaller a screen door effect would be visible. So you could move the pixels wherever you wanted but no greater detail could be realised.
If I were cynical, I’d suspect that technology to have been driven by marketing considerations rather than realistic engineering plans.
Anyway, things are different with the BenQ W11000 in two significant ways. Rather than 1,920 by 1,080 pixels – which comes to 2.07 megapixels – the resolution of this projector’s DMD yields 4.15 megapixels, or slightly more than half of the 8.29 megapixels of Ultra High Definiton. Smaller pixels permit greater detail.
In addition, DLP projectors switch their pixels on and off much faster than competing technologies. That in turn allows for precisely placement: if the engineers want, the pixels can be activated only at the ends of the pixel shifting range rather smearing their output along the length of their transit.
All that aside, the proof is that this projector can achieve complete Ultra High Definition resolution. While it is not quite as cleanly delivered as what you can expect from a device that simply maps the UHD signal directly onto all eight million plus pixels, it comes surprisingly close.
With regular content
It was a pleasure watching newer UltraHD material. I picked a number of scenes from Deadpool where the image is razor sharp and sitting less than three metres from my 2.1m screen, the results were dazzling. Everything was so sharp. I think sharper than the regular Full HD version of the movie.
What you see, though, is not like the jump from DVD to Blu-ray. It’s more subtle than that. In part because UltraHD is pulling ahead of all but the very latest capture equipment, and is considerably ahead of much of the processing in the special effects (these are still largely rendered at 2K).
Instead what you see is smoothly, more clearly defined edges. Fine details are slightly finer. The overall sense is one of greater realism.
What you won’t get with this projector is the higher dynamic range or wider colour gamut available from UltraHD Blu-ray. The projector is properly calibrated to the REC.709 high definition standard which makes for very accurate colour, but no ability to take advantage of the potentially wider range of colours from the new format. Likewise High Dynamic Range isn’t available, so in terms of brightness and contrast and gamma, things are pretty much the same was with regular Blu-ray (the projector communicates this to the player over HDMI so it knows to send the correct, compatible signal).
On the standards of regular Blu-ray, this proved to be a very good projector, with a good contrast ratio, respectable blacks, if not quite class-leading, and rich, accurate colours.
There were weaknesses in general use, in particular with 50Hz content of the kind available in Australia on a small proportion of Blu-ray discs, on the bulk of DVDs and on all broadcast TV. I’m told that the processing performed by the projector with its pixel shifting results in 120 frames being produced per second. Of course, 60fps divides evenly into 120, and so does 24fps (120/24 equals 5), which is how most movie Blu-rays and UltraHD Blu-rays are encoded (higher frame rate discs are expected to appear this year for the latter).
What doesn’t divide evenly into 120 is 50. So much Australian material is converted by the projector to 60fps, and clearly the technique used is to repeat every fifth frame. That results in jerky pans, and sometimes even jerky movement as characters move across the screen.
All that’s generally tolerable, especially to people who aren’t looking for it. But feeding it interlaced – that is, 1080i50 – signals should be avoided. The projector did very weird things to those, producing all kinds of visible distortion.
So, yes, there are limitations. But nonetheless, for a true Ultra High Definition picture on a big projection screen, there’s only one game in town for those who aren’t wealthy enough to afford Sony’s expensive offerings. And that’s the BenQ W11000.