The Optoma HD28HDR is a well-designed home theater projector. It delivers good color accuracy and contrast for movies and video at a high enough brightness to stand up to ambient light. It also offers a fast enough input lag to keep most gamers happy. The most notable qualities it shares with Optoma’s HD39HDR are support for high dynamic range (HDR) video and the ability to accept 4K (3840-by-2160-pixel) input to downconvert to its native 1080p. The list price is a steep $1,349, but it can often be found for less than half that, making it a bargain among projectors with those two features.
Imaging Chip, Color Wheel, and Setup Details
The HD28HDR is built around a 1920-by-1080-pixel DLP chip and a six-segment RYGCWB (red, yellow, green, cyan, white, blue) color wheel. The white segment delivers extra brightness, and the yellow and cyan help counter the white segment’s effects on color accuracy.
Setup is typical for a projector this size. It’s easy to handle, at just 6.2 pounds and 4.3 by 12.4 by 9.7 inches (HWD). Simply point it at the screen, adjust the 1.1x zoom, and focus. If you need to tilt it up or down, you can square off the image with the +/- 40 degree keystone adjustment. Inputs include two HDMI ports, but only one is HDMI 2.0, the minimum required for 4K 60Hz resolution. The other is HDMI 1.4b, suitable for up to 4K 30Hz. Both support HDCP 2.2, the copy protection scheme that almost all 4K HDR discs use. For my formal tests using a 90-inch screen, I set the projector up using maximum zoom (for shortest distance for the image size) at 9 feet 6 inches from the screen.
The lag time is 16.4ms at 1080p, 60Hz in Enhanced Gaming mode, according to my Bodnar meter, and consistent with the rated 8.4ms at 120Hz. The main reason Optoma leaves the projector off its list of gaming projectors is that most gamers want a projector with robust audio that they can move from one location to another. The HD28HDR’s onboard 3-watt speaker delivers only enough volume for a small family room, and the sound quality is somewhat tinny. You’re best off leaving it in one place and using external speakers.
SDR Scores Better than HDR
Don’t get too excited about the HD28HDR’s support for HDR. In my tests, standard dynamic range (SDR) versions of movies actually looked better than the HDR versions. The good news is that the image was highly watchable with both, and there was very little difference in brightly lit scenes.
My pick for the best predefined picture mode for SDR movies and video is Cinema. It delivers good color accuracy, nearly neutral grayscale, and a dark enough black level to serve well in ambient light. In a theater-dark room, none of the picture offers the contrast, sense of three-dimensionality in dark scenes, and truly dark black that a videophile would want, but Cinema came closest, delivering the most dramatic-looking image of any mode.
Reference mode provides slightly better color accuracy—though most people wouldn’t notice the difference without a side by side comparison—and an even more neutral grayscale. However, it’s obviously dimmer than Cinema mode, and doesn’t show as much shadow detail (details in dark areas).
If you need a brighter mode than Cinema—for daytime use in a family room, for example—Game and Vivid modes are both useful alternatives. They have approximately equal brightness and more than acceptable color accuracy. Game mode’s color accuracy and shadow detail are better. Bright mode has a noticeable green shift, as is typical for the brightest mode in most projectors, but it should be tolerable at least on an occasional basis, like a particularly bright day.
For HDR input, the HD28HDR supports HDR10 only, the version on most 4K HDR discs. When it sees HDR10 input, it automatically switches to its one HDR picture mode, makes the other modes unavailable, and downconverts the image to its native 1080p.
In my tests, brightly lit scenes in the HDR versions of movies on disc looked essentially the same as the same movies in 1080p SDR format. Some hues were shifted a bit, but memory colors, such as green grass and blue sky, were all well within the realm of realistic.
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Unfortunately, dark scenes in the HDR versions were hurt rather than helped by the conversion. The darkest areas in the images were brightened up to the point of looking slightly washed out, and I didn’t see as much shadow detail. The projector has four HDR brightness settings, which are meant to let you compensate for differences in the way individual movies implement the HDR10 spec. But while they made some difference in particularly bright scenes, none of them made any visible difference in dark scenes.
The Society of Motion Picture and Television Engineers (SMPTE) recommendations peg 3,600 lumens as suitable for a 155-inch, 16:9 image using a 1.0-gain screen in moderate ambient light. For Cinema mode’s lower brightness, however, plan to use a smaller screen. For my formal tests in a dark room, it was easily bright enough to light up a 90-inch white screen. For informal tests in a family room, it served nicely using an 80-inch, 1.0 gain screen with lights on at night.
As with most DLP projectors with Full HD 3D support, the HD28HDR works with DLP-link glasses and offers a single 3D picture mode. Also typical is that the 3D mode isn’t as bright as any of the 2D modes. However, it was bright enough for a 90-inch image to be highly watchable in a dark room. I saw no crosstalk in my tests, and 3D-related motion artifacts were less obvious than typical for current models.
Rainbow artifacts—red-green-blue flashes—can crop up with any single-chip projector, but the few I saw with the HD28HDR were infrequent and fleeting. That said, be sure to buy the projector from a source that allows returns without a restocking fee, so you can judge this issue for yourself.
A Good Balance of Features and Price
The Optoma HD28HDR combines a highly watchable picture for movies and video, high enough brightness to stand up to ambient light, a fast lag time for gaming, and availability at a low price for a projector that supports HDR. If you don’t care about HDR, you’ll do just as well with a less expensive projector such as the BenQ TH585 or Optoma HD146X. If you don’t mind paying more for a projector that delivers on some of the promise of HDR, consider the Optoma HD39HDR or the BenQ TH685. But if you simply want a projector that costs as little as possible and supports HDR—maybe so you can build a collection of HDR discs to watch while you’re waiting for a sufficiently low price on that 4K HDR ultra-short throw laser projector you really want—the Optoma HD28HDR can be exactly the right choice.
