Posted on December 20, 2017 By Ron Jones
Optoma UHZ65 4K Capable Home Theater Projector – Special Features: UHD Resolution, HDR Support, Wide Color Gamut, Laser Light Source, Color Wheel, CFI, Other Image Enhancing Features, Network Management Support, Lens Shift
Originally the FauxK or 4K-lite terms were applied to pixel shifting 1080p resolution projectors – JVC first, then Epson as they rolled out a whole line of them. Those projectors going back to 2011, could accept 4K content, processed it, and fed it to chips that could fire twice, shifting a half pixel diagonally. This allows for more detail, but the pixel size (relative to true 4K) is huge – twice the diameter, four times the area for a true 4K projector. Think of 4K as a baseball, and 1080p pixel shifters as a softball, in terms of pixel size.
Now enters the new TI consumer chip which also pixel shifts. It splits the difference in resolution at 2716×1528, just about half way between 1920×1080 and 3840×2160. But, like the lower resolution pixel shifters, it still uses large pixels compared to true 4K, but now only twice the area for a true 4K projector.
So the Optoma UHZ65 ability to display the finest details in a 4K image falls somewhere between that of a 1080p pixel shifting projector and a true native 4K projector (assuming they have equal quality lenses and the 3-chip projector has excellent alignment of the RGB panels).
In any case the UHZ65 is capable of projecting some very sharp images when connected to a good 4K video source.
For the case where the UHZ65 is to be used in a business or education application, the added resolution, as compared to a 1080p projector, could be a plus for certain applications, such as the display of detailed engineering drawings.
There are three major components touted when it comes to UHD. Obviously, first, is the 4K resolution itself. But some people may find one or both of the other UHD enhancements equally important. To take advantage of all that UHD has to offer also requires support for High Dynamic Range (HDR), and Wide Color Gamut (WCG). I’ll address HDR here, and WCG below.
HDR – makes a difference. I like to think of it this way when using it. It essentially has a different gamma curve – the picture is displayed with a greater difference in relative brightness between the brightest content (eg., sunlight glint off of shiny surface), and average brightness content. This gives the image more pop, less “compression” of the image’s dynamic range (in theory), and overall is a desirable feature. But for best results it does need lots of brightness, a good native contrast and low black levels, so there’s plenty of opportunity for compromise – both with all home theater projectors, and for that matter with all but the most expensive of the “4K” LCD TVs and OLED TVs.
The UHZ65 can detect when HDR is present for the incoming 4K/UHD signal and automatically switch to HDR image (picture) mode where there are multiple levels of HDR image brightness offered via the projector’s menu. Each essentially applies a different gamma curves intended to display HDR content. This projector also has settings for “Brilliant Color” and “Dynamic Black” and all these settings adds up to a lot of options for how the video is going to be displayed.
The user will need to select the specific settings that best match both the characteristics of their specific setup (overall image brightness with their specific screen size and gain along with projector’s settings) as well as the setting that works best with the specific HDR program (some are mastered darker or brighter than others). It sounds a little complicated, but once it’s setup you will probably only need to make a single adjustment to account for the difference in brightness between different HDR content (i.e., different Ultra HD Blu-ray movies or different streaming video services).
There are 2 potential limitations to how effective the UHZ65 is in displaying HDR video. The first is true for virtually all consumer projectors and that is the peak brightness for the brightest image highlights will be much less than with the most capable HDR enabled flat panel displays. The peak brightness that can be achieved when using a projector depends not only on the light output of the projector, but also on the size and gain of the projection screen being used . With a HDR flat panel display the peak highlights can be displayed at up to 10 times the brightness of the reference white level while with a projector the peak highlights can usually be displayed with a brightness that is no more than 2 or 3 times the reference white level. As a result, the visual impact of HDR will not be as great with a projector based solution.
I would also note another complication is the HDR videos (using the HDR-10 standard) are being created assuming the display will support the brightness levels associated with HDR enabled flat panel displays and there are no existing standards for how to “tone map” these HDR videos for display on a less bright HDR projection system.
While I’m usually not a fan of the “Brilliant Color” feature found on many DLP single chip projectors. I did find that in this case cranking the adjustment up from 1 (off) to a value of 8 (just 2 short the max. setting of 10) did make HDR content appear more dynamic and that’s what HDR is all about.
I must also note that the UHZ65 has a rather limited native contrast ratio and moderately elevated black levels, but with the aid of the “Dynamic Contrast” (i.e., dynamic laser dimming) it certainly puts up more dynamic images than what I’ve seen from the lamp-based, but otherwise similar, DLP 4K projectors.
Like the other DLP 4K/UHD projectors, Optoma’s literature may talk about wide color gamut and being compatible with Rec. 2020 and DCI-P3. The figure below shows the measured color gamut of the UHZ65 when it is operated in is native (i.e., widest) gamut mode.
However, in fact the UHZ65 is essentially limited to Rec. 709 color space, and as shown in the above figure it’s native color gamut measured less than 10% per cent wider than Rec. 709 (the inner triangle) and fell well short of DCI-P3 color gamut (the outer triangle). After calibration this color space shrunk to just a very little wider than Rec. 709, so this basically is a Rec. 709 projector.
I would note that the wider DCI-P3 color space is reached by the best of the 4K capable projectors out there, both lamp-based and laser-based, while full Rec. BT2020 color space is not yet supported, nor yet needed, for consumer 4K/UHD projectors.
The wider that color gamut, the more intense the colors can be. For example, the brightest, most saturated color red you see on tv, say a red balloon, is no match in terms of color compared to that same balloon in real life. Support for DCI-P3 color space would get us a good step closer to real, and puts us on par with digital cinema projectors. The ability to project a much wider color gamut than Rec. 709 falls short on the Optoma UHZ65. The bottom line is the UHZ65 can accept signals that support WCG but the colors are essentially displayed at the more limited Rec. 709 values, the same as with HDTV.
The UHZ65 uses a laser light source instead of a conventional light source. Optoma’s spec. sheet for this projector lists the estimated life for the lasers at 20,000 hours, which is typical for laser projectors. Such light engines usually use blue lasers illuminating a phosphor target that produces yellow light that is then mixed with the direct blue light from the lasers to produce a white light. I don’t have any information from Optoma to verify this is what is being done within the UHZ65’s light engine, or if they are using another arrangement. In any case this projector has fairly high usable brightness with more on that later in this review.
Outside of a home theater application, the laser light engine may be a strong selling feature for certain business/classroom applications where the reduced maintenance requirements, as compared to a lamp-based projector. can be important.
Single chip DLP projectors use a color wheel containing segments with color filters as a means of delivering, at least, the primary colors sequentially to the single DLP display chip. The UHZ65 uses a Red/Green/Blue/Yellow (RGBY) color wheel. While generally color wheels using only RGB filter segments is the preferred arrangement for home theater projectors (that’s what Optoma uses for their lamp-based UHD65 model), it appears the addition of the yellow segment is used here as a means for boosting the projector’s maximum brightness, at least for whites and perhaps light color shades.
Creative Frame Interpolation – CFI – sometimes called smooth motion, is offered under Optoma’s trademark name of Pure Motion. It works.
Many potential buyers may like CFI for sports viewing but don’t like the effect it has for movies and even most HDTV viewing other than sports. Optoma offers multiple settings, which is good. Where they come up a bit short – even their lowest does more to the image than most other projector’s CFI, in that it is more noticeable. We often refer to that CFI look as soap opera effect, or “live digital video” (with faster frame rates than the slower movie frame rate of 24fps.) Theirs is not too much for sports viewing, but most will probably find it not acceptable for viewing movies.
I consider CFI to be a nice extra feature overall, rather than a critical one that a projector needs (some sports fans might disagree).
The Optoma UHZ65 has a number of other forms of image enhancement:
Ultra Detail – image processing to improve perceived sharpness and detail
Black levels – Dynamic Black, which is a laser dimming technique to lower black levels on dark scenes (same idea as a dynamic iris). There are 3 levels of Dynamic Black offered and there is also a setting that turns this feature off and lets you select a fixed value for the overall brightness (i.e., to run the laser at full power or in a lower power mode). Unlike with lamp-based projectors (including the previously reviewed UHD65), the UHZ65 laser’s light output can be controlled fast enough to provide some real benefits for allowed the Dynamic Black function to lower the black level on dark scenes and overall providing results similar to a dynamic iris.
There’s also Pure Color, and Pure Contrast. (I’ll let you guess what those are supposed to do.) For calibration and review purposes, we did not use these two. Oh, and as this is a DLP, of course there’s Brilliant Color. (Optoma’s version offers settings from 1 to 10 of Brilliant Color with 1 presumably being off). I’m usually not a big fan of the Brilliant Color feature on DLP projectors, but in this case it appears that it does add extra dynamics for when video when HDR content is being displayed.
The UHZ65 supports control and management via a wired network (Ethernet) service and also control via an “old fashioned” RS232 connection. The UHZ65 is compatible with control systems from Crestron, Extron, AMX and computer based management using PJLink software. It can also be controlled from a web browser based interface. So this model will satisfy most business/education needs for control and management of their multi-projector installations.
As with some of the other 4K DLP projectors we have recently reviewed, the UHZ65 offers vertical optical lens shift with a limited 15% range. With a typical home theater size screen this means the image can be shifted over an approx. 8″ to 12″ range.
While that’s much more limited than what you get with most 3LCD or LCoS based home theater projectors, at least those in the $2000+ price range, it’s still enough to provide some useful flexibility in the projector mounting location.
OK, that’s enough special features for now. Let’s take a look at the hardware!
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