Review: Optoma UHL55 UltraHD smart projector

The gap in functionality between TVs and projectors is cavernous, but Optoma appears to be addressing the disparity. Stephen Dawson reports.

Just about all home theatre projectors are nothing but that: projectors, with no additional functionality. By contrast, a modern TV is a computer, with full access to the internet, and often with the ability to even understand human speech. Well, interpret it, anyway.

Projectors? Not so much. But Optoma might be changing that with the UHL55 UltraHD smart projector. And doing it at a startlingly low price.


What it is

This projector is a small unit, adopting the shape of a 220mm square when looked at from the top. It stands 135mm tall. Although it’s clearly intended for desktop operation, it does have the usual image flip and reverse functions to allow for flexible installation.

At the front is a slide cover over the lens. The projector can’t be switched on without sliding this clear. There is no zoom and no lens shift. If the projector is being installed, care should be taken to get the geometry just right, and mounting bolts shouldn’t be tightened until a little trial and error is practiced.

The projector is fairly short-throw. For a 100” (2.54m) 16:9 screen, the projector should be placed at a range of 2.66m. Focus is electronic. Tap the buttons until the image is sharp. A test pattern is available in the menu. There’s also an ‘autofocus’ function, but that only works at a range of up to 2m (which means an image size of no more than 75”). I wouldn’t bother. Getting a sharp focus with the manual controls was a snap.

The light source is solid state, using LED lasers and phosphors. It’s rated at 1,500 ANSI lumens output, and a lamp life of 20,000 hours. The lamp assembly is not user replaceable, since the chances of anyone managing to wear it out are negligible. That works out to more than 13 years of four-hours-per-day use.

The projector offers UltraHD (3,840 by 2,160-pixel) resolution, using one of Texas Instrument’s 0.47” DMDs with pixel-shifting technology. I’ll return to that.

There are two HDMI inputs – both support UltraHD and HDCP 2.2, for use with UltraHD Blu-ray – a two USB sockets and both WiFi and Ethernet.

But this unit is also smart. It runs a tightly controlled version of the Android operating system. There’s about 10GB of storage available, although you can add more by using one of the USB sockets.

There’s no obvious access to the underlying Android system, but many of its facilities are quietly available. For example, you can plug a regular mouse/keyboard combination into one of the USB sockets. That’s useful for doing things like entering passwords or browsing the Internet.

Indeed, the Firefox browser available in the Optoma Marketplace (accessible via a pre-installed app) displays a warning on the download screen that you need a mouse to use it.

Also available are such apps as Netflix, YouTube TV, TED TV, Spotify and a couple of news channels. That’s pretty much it. You don’t have access to the millions of other Android apps. Still, things like Netflix are useful.


Now, let’s return briefly to the display engine of the projector. As with all UHD DLP projectors, the Optoma UHL55 uses XPR to expand the native resolution of the display panel to the 3,840 by 2,160 pixels of UltraHD resolution. But the term XPR – ‘eXpanded Pixel Resolution’ – seems to be becoming deprecated. Wherever you read about this chip and this projector, it’s just outright stated that the resolution is UltraHD.

In fact, the native resolution is 1080p, but it moves by the tiniest amount four times for each frame, creating four dots in four quadrants of each point of a 1,920 by 1,080 array. That shouldn’t be so surprising. All single-chip DLP projectors paint their colour sequentially rather than overlaying them. So, in this case, a DLP projector also paints some of its pixels sequentially.

However, that means the projector is locked into a display frequency of 60 frames per second. Since most material watched in Australia is either 50fps or 24fps, motion tends to be visibly jerky, the more so with 50fps stuff. To convert 50fps to 60fps, every fifth frame has to be repeated once. To convert 24fps to 60fps, some of the frames are kept up for two 60Hz cycles, and the rest are kept up for three. You wouldn’t think that such things would be visible, but it is clearly so.

The question then is: well, does this system actually resolve down to UHD? Answer: yes it does. In fact, I think it provides a crisper result than that delivered by the more expensive 0.66” DMDs which Texas Instruments also offer as an UltraHD solution. My test patterns showed that each pixel was displayed. Not, to be fair, as clearly as an UltraHD TV panel, but still quite well.


The projector came to me pre-used. As usual, I chose the ‘reset’ function, but I’m pretty sure that only applied to the projector functions, not to its smart functions. According to the manual there’s a wizard that guides the unit through setup the first time it’s switched on. It didn’t appear for me, so I just hit the ‘Home’ key, arrowed around until I found ‘Settings’, then ‘Network’, and connected to WiFi there. All went smoothly.

Once that was done, the projector checked home and found that there was a new firmware available. That downloaded and then installed automatically.

I installed the Netflix and Firefox apps from the Marketplace. Again, all went smoothly there.

And then I went ahead with the most advanced smart feature available in this projector: voice control.

Yes, you can set up the projector to allow voice control using either the Google Assistant system or the Amazon Alexa system. Both require linking them with a free Optoma account to which the projector is connected. I used the Google system. I have a Google Home Mini in my office. I could switch the projector on, change picture modes and a few other things.

Is this useful? Not particularly, in my opinion. It’s generally easier just to grab the remote control and push a few buttons. But, by golly, it does make a good party trick. I suppose there might be some scenarios where you might want to use off-site control. And, anyway, the whole voice remote control thing is still in its infancy. I can imagine this capability being deepened and widened into something truly useful.


The projector has a couple of little speakers built in. They weren’t as horrible as they ought to have been, but even so just about any audio system is going to be an improvement. Optical digital audio and analogue audio outputs can be used for that, as can Bluetooth.

One clear weakness of this projector, given that it has the ability to act as a source device (for example, with the Netflix app) is that it doesn’t implement the Audio Return Channel. That would be the ideal way to feed audio back to a connected home theatre receiver, given that the HDMI cable will be there anyway. But since there’s no ARC, sending sound back to a receiver will require connecting with optical cable (very expensive for long runs) or analogue.


As a projector, the Optoma UHL55 did a rather good job.

It typically took about 20 seconds to start up. What slowed things down was Android booting up, not the projector getting its lamp lit. That’s capable of being instantaneous; one of the advantages of a LED/laser light engine.

The resulting picture was nicely bright and certainly capable of being seen under fairly bright fluorescent room lights. But of course, it’s appropriate to watch it in a darkened room. The black levels were quite impressive, and that in turn allowed rich and accurate colours.

The projector supports HDR signals, but there are limitations with what it can do with them. Clearly there isn’t enough range for the projector to run from 0 nits to 10,000 nits. What it seemed to do was resolve brightness level differences between 0.01 nits and 0.05 nits, below which the levels were crushed into a consistent near-blackness. At the bright end the crushing into a consistent white commenced up around 1,000 nits. But there’s very little material that makes full use of the space above a thousand nits, so in practice there were good, smooth transitions across gradients.

That judder resulting from the conversion of 24 or 50 frames per second to 60 (the latter is much worse) could be mitigated a little with a frame interpolation system available within the picture settings.

One last thing: the projector does a terrible job with 50Hz interlaced standard and high definition material. All 50Hz content absolutely must be converted to progressive scan before being fed to this projector.

Not once did the rainbow effect make an appearance, thankfully.

Other smarts

There’s a media player apps pre-installed in the projector. This did a good job with just about all my test files, video, photo and music. It also seemed to want to provide access to DLNA content on the network, but it remained buggy, selecting the wrong network resource.

The projector does not implement Chromecast, nor does it act as a DLNA renderer, so you can’t get around that defect by sending network content using another device.


I hope this product category is a success. Combining a product-life lamp, UltraHD resolution and some of the smarts routinely found in TVs is an exciting development.

However, there is that issue with judder. That troubles some viewers a great deal. To others it’s invisible. Those considering this projector should check it out in-store first before committing.

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Reference: Connected Home