Vivitek HK2288
Things are in flux with 4K at the moment. New 4K projectors at quite startling prices are appearing relatively regularly these days, but as always, not all 4K is the same. The Vivitek HK2288 projector is one of the models that does in fact generate real Ultra High Definition images, achieving this by using a four-megapixel Digital Micromirror Device along with Texas Instruments’ XPR pixel-shifting technology.  
Of course, Ultra High Definition actually requires 8.3 megapixels. And for a couple of years there have been projectors around using some form of pixel-shifting technology to, they say, generate Ultra-HD images. But some of these have been based on 1080p technology. To quadruple that resolution you need two things. The first is the ability to shift the pixels slightly to four different positions. That they can do. The other is pixels that are small enough that they will fit into the gaps between the other pixels, rather than overlay them. And that they generally can’t do.
But this new chip does use smaller pixel sizes, since it has double the resolution of a 1080p system. And with a relatively simple shifting of pixels between two positions, rather than four, a proper Ultra High Definition image is achievable. (And, in fact, achieved.)
So, briefly onto the rest of the projector. It uses a 310W conventional lamp to deliver up to 2000 lumens of brightness to the screen. It has a 1.5-to-1 zoom range and a manually adjustable vertical lens shift to ease installation.
It has several aspect ratios accessible via dedicated keys on the remote control. One provides support for anamorphic lenses, scaling a somewhat taller image so that it will display in the correct aspect ratio in a constant image height system with the use of an anamorphic lens.
We haven’t been fans of this kind of thing in the past, considering it more important that input pixels be precisely mapped to output pixels. (Scaling by a fraction in any direction makes that impossible.) But Ultra-HD displays have changed that. With so many more pixels available, the picture is far more tolerant of scaling, and this projector seemed to do a fine job of it.
The lamp is rated at between 2500 and 4000 hours depending on the brightness level you choose. Contrast ratio is rated at 50,000:1.
Vivitek HK2288
As you might know from us mentioning DMDs, the projector uses DLP technology and runs a six-segment RGBRGB colour wheel. It has three HDMI inputs — all support Ultra-HD signals and HDCP 2.2, which means compatibility with Ultra-HD Blu-ray players. There’s a Micro-B USB port for service purposes (meaning firmware upgrades) and a regular USB port which is there solely to provide power, should you plug in a Chromecast or other dongle for streaming.
There’s also a 3.5mm audio output socket. The projector can decode audio from HDMI and send it out there, or deliver sound via its own built-in 10W mono audio system.
Out of the box most of the settings were pretty much spot-on. A grey-scale test pattern was properly shown, with full white and whiter-than-white indistinguishable from each other. Likewise for full black and blacker-than-black. Perhaps things are a bit more basic than the considerable massaging many TVs these days give a signal, but the Vivitek nevertheless gave confidence that what it was delivering was pretty much what was in the signal, subject only to hardware limitations. In addition to being properly calibrated as to brightness, there was also no colour shift in any of the greys.
Setting up was pretty straight-forward, bar only for the oddly-placed focus adjustment, which is half hidden under a kind of lens hood. We found it hard to get quite the amount of purchase we would have liked without putting enough pressure on the projector itself to knock it out of alignment.
But a bit of persistence dealt with that, and we settled in to see what it delivered.
Smooth. We really enjoyed the picture produced by this projector. You kind-of expect an Ultra-HD projector to almost poke you in the eye out of sheer sharpness. But in reality there is not all that much content that resolves right down to that level. Some graphics, of course, and all those showy UHD clips that we’ve gathered from various product launches. But existing Ultra-HD Blu-ray discs? No. Properly delivered they are smooth. Diagonals are jaggie free. And remember, in the real world nearly every edge is a diagonal. At the limit (mathematically speaking) a circle is diagonal at all but four points.
But it was more than just smooth edges. The colour was invitingly natural, especially in outdoor scenes. That was the case both for Ultra-HD Blu-ray and even with the relatively colour-constrained palette of regular Blu-ray. After all, Blu-ray is designed around the Rec.709 standard, and that’s the space in which this projector operates.
Vivitek HK2288
We spent a fair bit of time with the film Miss Potter for reasons we’ll come to shortly. The latter half of this is largely set in England’s Lake District, with some of the most beautiful rolling meadows ever captured on film. The Vivitek HK2288 seemed to positively luxuriate in all this. 
We’ve been spoiled for black levels lately, thanks to OLED TVs, and even the best projector has trouble providing as impressive levels of contrast. But for the most part, the black levels here were quite satisfying. We’ve remarked on this before, but there’s some threshold level of black once achieved that, even though it remains imperfect, is thoroughly satisfying subjectively. This projector managed that. Even in screen-wide, dull-lit scenes, the results were impressive. In the recent Ghost in the Shell, viewed on Ultra-HD Blu-ray, most of the action is at night. The full blacks were quite deep, and even though technically significantly short of fully black, the projector did a nice job of distinguishing the different levels of blackness so that details weren’t obscured. The hooded face of Michael Pitt, the villain, was still real, still contained detail, even though near black.
The real weakness of this DLP system is in handling different frame rates. Which brings us back to Miss Potter, as well as the great majority of Australian DVDs. These run at 50 fields per second, and that is a figure that cannot be elegantly multiplied into the 60Hz at which the XPR pixel-shifting here operates. This projector achieves the conversion, it looked to our eyes, by repeating every fifth frame. Those slow pans over Miss Potter’s luscious countryside were turned into a series of visible steps — repetitive little steps... the antithesis of the smoothness of the image itself. (Incidentally, or perhaps relatedly, the deinterlacing of 1080i/50 and 576i/50 was uniformly poor, with very little attempt at identifying film-source material for proper handling. Instead, seemingly all content was treated as video-sourced, and handled in this mode with motion-adaptive deinterlacing.)
And of course 24 frames per second — which is what nearly all films are shot at — don’t go very well into 60 either. Here things were less clear. We were expecting similar but less obvious jerkiness, which is what we’ve generally found with other systems using a naive 24-to-60 conversion (achieved by repeating frames twice, then three times, thus: AA-BBB-CC-DDD etc). Again we went to Ghost in the Shell, thinking those long swirling pans would make the weird cadence obvious. But if it was there, it was very subtle. On a couple of occasions we thought we saw it, but it’s possible it was our imaginations since we were looking so hard. We tried a couple of scenes on a Blu-ray disc with which we’re very familiar, to similar inconclusive results. There was a clear judder, but we’re inclined to think that it was the standard stepping inherent in DLP on a big screen. Because the pixels switch so fast on DLP, there’s no accidental smoothing of 24p motion. We’re wondering if Vivitek has designed this projector so that it can in fact switch to 24fps, or possibly used some frame merging for its 60Hz, so that instead of AA-BBB, it does AA(A+B)BB.
Almost needless to say, there is no frame interpolation, so any material inclined to judder is going to judder happily away. 
So the Vivitek HK2288 is an impressive Ultra-HD projector, indeed one of the most impressive projectors we’ve seen in quite a while. Aside from the cadence issues with 50Hz content here, we’re impressed with the contrast and colour of this projector on the big screen, and we note also a pleasing raft of ‘green’ inititatives at Vivitek — lead-free operations, recycling use, a strong emphasis on low-power consumption.   
And at the asking price of $4999, it’s really quite the bargain. Regular Blu-ray looks top notch, and Ultra-HD Blu-ray steps into near virtual reality. 
Vivitek HK2288
Vivitek HK2288
Ultra-HD AV projector
Price: $4999
+ Excellent value for money
+ Lovely smooth UHD picture
+ Excellent colour, with strong black levels
- Jerky with 50Hz signals
- Cadence detection with interlaced 50Hz
Projection technology: 1 x 16.8mm 
DarkChip3 TRP Digital Micromirror Device
Resolution: 3840 by 2160 pixels
Aspect ratio: 16:9
Lamp: 310 watts
Lamp life: 2500/3500/4000 hours (Normal/Eco/Dynamic Eco mode)
Contrast ratio: 50000:1
Brightness: 2000 ANSI Lumens
Inputs: 3 x HDMI (all with UHD support)
Other: 1 x RS-232C, 1 x USB-A (for power), 1 x Micro-B USB (for service), 1 x 3.5mm audio out
Dimensions (whd): 430 x 145 x 360mm
Weight: 9kg
Warranty: Three years