The $1,699 BenQ HT3550 (currently available for $1,499) and $1,699 TK850 are all but identical in specs, features, and physical design. But what few differences there are put them worlds apart in functionality. Quite simply, the HT3550 delivers a wider color gamut and better color accuracy, making it the preferred choice for watching movies in a dark room. The TK850 offers significantly higher brightness—at a rated 3,000 ANSI lumens rather than 2,000—making it the better choice as a TV-replacement in a room with ambient light. If this arrangement sounds familiar, it may be because BenQ's prior generation of each model, the HT2550 and TK800, were also intended to serve these specific applications. You can click our links to read our individual reviews of the HT2550 and TK800, and access our star ratings and summary Pros/Cons for the new TK850 here. For additional details on shared features for the TK850, refer to our standalone review of the HT3550.
Both the HT3550 and TK850 are built around the same .47-inch DMD chip, which uses TI's XPR fast-switching pixel- shifting to put 3840x2160 pixels on screen, and both offer HDR support. They even use the same lamp, which means they start with the same brightness. The difference in lumens stems primarily from the choice of color wheel. The white panel on the TK850's RGBW wheel lets more light through to boost image brightness, while the HT3550's RGBRGB wheel delivers better color accuracy and a wider gamut.
The mostly shared specs between the two projectors also include a 30,000:1 contrast ratio (full on/full off with dynamic iris on); the same onboard audio system; and the same 1.3x zoom lens to give them matching throw distance ranges, lens offsets, and 10% vertical lens shifts. That leaves only a few key differences between the two.
Key Spec and Feature Differences
Color Gamut. The HT3550 is the easy winner between the two for color gamut. It's rated at 100% Rec.709 color gamut in D. Cinema mode, 97% Rec.709 (at a higher brightness) in Cinema mode, and 95% DCI-P3 in the predefined version of the User mode. The TK850 is rated at only 98% Rec.709 coverage (in Cinema mode), and BenQ doesn't publish a rating for its DCI-P3 coverage.
Color Accuracy. One indication of the difference in color accuracy between the two projectors is the difference in BenQ's claims for each one. The company says the HT3550 delivers a Delta E for color of less than 3 straight out of the box. (Delta E is a measure of accuracy. A Delta E of 3 or less is generally considered too little to notice.) It also does a factory calibration for each HT3550 it ships and includes the calibration report with the projector. BenQ says it does a factory calibration of the TK850 as well, but it doesn't make a specific color accuracy claim for it, and it doesn't provide a factory calibration report for each unit. Note also that to get the best color accuracy for the TK850, I had to set the DLP Brilliant Color control to 0, which lowered brightness significantly. (See the later comments on calibration.)
Brightness. The TK850 pretty much blows the HT3550 away for brightness. To begin with, its 3,000 ANSI lumen rating is 50% higher than the HT3550's 2,000 lumens. And although colors are a little washed out in the TK850's Bright mode compared with the HT3550's equivalent, the image is more watchable, because it doesn't have the noticeable green bias that shows in the HT3550's Bright mode.
Even ignoring the brightest modes, the TK850 is the brighter of the two. With default settings, its color modes that you're most likely to use fell in a tight range of roughly 1,475 to 1,580 ANSI lumens at full power by our measurements, compared with a range of roughly 550 to 785 lumens for the HT3550—a 100% to 200% advantage for the TK850, depending on which modes you compare. The TK850 is even brighter in Economic mode than the HT3550 in full power mode, with a range of roughly 1,000 to 1,065 lumens for the TK850's Living Room, Cinema, and Sports modes.
Both projectors also offer a Silence mode that turns off the imaging chip's XPR pixel-shifting and reduces resolution to the DMD's native 1920x1080 array in favor of quieter operation. It's hard to believe that anyone would pay extra for a 4K projector and then turn the 4K feature off. But if you plan to do so, note that the TK850's Silence mode, which is its least bright mode, is still brighter than any of the HT3550's color modes except the green-shifted Bright mode.
Image size. Ignoring the brightest modes once again, the brightness difference between the two projectors translates to an enormous difference in usable image size with default settings. In a room with low to moderate ambient light, like a family room with lights on at night, the TK850 is bright enough to light up a roughly 100 to 115-inch, 1.0-gain screen—using guidelines for SDR, at least, and depending on the color mode and precise light level. To get the same image brightness, the HT3550 would be limited to a 70 to 90-inch screen even with 1.3-gain screen material.
In a dark room, using calibrated modes with each projector, image brightness is similar for both, and suitable for a roughly 110-inch, 1.3-gain screen at the conventional 16 ft-Lambert (ft-L) recommendation for SDR viewing.
Input Lag. For both projectors, the input lag at 1080p is a touch too long for even casual gaming, but the HT3550 does a little better on this score at about 60 ms compared with about 82 ms for the TK850. The measured lag at 4K drops to about 50 ms for the HT3550, which many consider acceptable for casual gaming. The TK850's measured lag at 4K is 86.5 ms.
1080p/SDR Viewing. For the side-by-side comparisons I first calibrated both projectors, and then viewed a variety Blu-ray discs as well as movies and filmed TV shows on Netflix. Using a splitter, I was able to see the images simultaneously in all cases—for SDR, HDR, and 3D. I also did the comparisons both in a dark room and with ambient light typical of a family room at night.
For 1080/SDR dark-room viewing, the HT3550 delivered the superior image, as expected, thanks primarily to better contrast and darker blacks, which also combined to give it a slight, but noticeable, boost to the sense of three-dimensionality.
Viewed by itself, the TK850 did well enough on all three scores so most people would judge the picture as more than acceptable with no obvious shortcomings. Viewed side by side, however, the black in the darker barroom scenes in The Irishman, for example, looked gray on the TK850 when compared to the black in the HT3550's image, and contrast was enough lower to make the overall image look slightly washed out in comparison to the HT3550's picture.
The TK850's lower contrast also lead to colors looking less saturated than with the HT3550 in both dark and brightly lit scenes in every clip I looked at, from The Irishman to the opening song and dance on the highway in La La Land—which is filled with eye-catching primary colors—to the animated content in The Secret Life of Pets. The HT3550 also showed off its obviously darker black in the Universal logo with its background starfield as well in title screens with black backgrounds.
The nature of color differences between the two projectors varied with the material. Hues were noticeably different between them in The Irishman, for example, which was most obvious with faces. But both projectors were within a realistic range, so you wouldn't know which, if either, was closer to the original without a reference for comparison. On the other hand, most hues matched in the opening scene in La La Land, and it was only the saturation that differed.
As you would expect from two projectors with the same lens and imaging chip, the images delivered identical levels of detail. Both also offered even focus across the entire screen.
Turn on the lights, and the advantage switches to the TK850. In their calibrated modes, neither projector stood up well to ambient light in the absence of an ALR screen, and exhibited the expected washing out of shadow detail and color saturation at low levels of image brightness. After switching to brighter color modes using their default settings, however, and with black levels still washed out for both projectors, the TK850's higher brightness delivered clearly better contrast and color saturation in darker scenes. In bright scenes with ambient light, the HT3550 delivered slightly better contrast and color saturation, but there was little difference between the two on those images.
Also helping tip the scales in the TK850's favor for use in ambient light is that the HT3550's brightest mode has the obvious green bias mentioned earlier, while the TK850's Bright mode delivers far more acceptable color by most people's standards. This makes the TK850's Bright mode a highly usable option when that extra brightness is needed.
UHD/HDR Viewing. The most obvious difference between the two projectors for UHD/HDR viewing in a dark room was the same as for SDR viewing—a much darker black for the HT3550 along with better contrast and sense of three-dimensionality in dark scenes. In views of starfields in The Martian for example, the HT3550 delivered a far darker background for space than the TK850, and better contrast with the bright stars and white spacecraft.
In my go-to dark scene in Batman v Superman, when the young Bruce Wayne discovers the future bat cave filled with bats, the black level was also far darker for the HT3550, making the glowing red bats' eyes much brighter in comparison. Both showed roughly equal shadow detail, but the far greater contrast in the HT3550's image made it that much more dramatic.
As with SDR material, differences in colors between the two varied from one movie to the next, and even from one scene to the next in the same movie, but they were close enough to each other that without measurements or a reference image there was no way to tell which was more accurate.
In the opening scenes of Batman Begins, the TK850's version of the prison walls were a more neutral gray, for example, while both projectors delivered closely matched flesh tones for Christian Bale's and Liam Neeson's faces. In the later scene where Bruce Wayne is dropped off at the foot of the mountain he needs to climb, blue patches in the overcast sky are more obviously blue in the TK850's image, rather than a bluish gray, and the grass is a little darker green. And in the opening dance number of La La Land, hues for almost all the car and clothing colors were different between the two projectors when viewed in HDR, but both delivered nicely saturated, bright color, even for yellow, which is often difficult for DLP projectors.
The conventional wisdom that projectors should be limited to viewing in a dark room for HDR holds true for both models. Even when I shrunk the image sizes to only about a 65-inch diagonal on my 1.0-gain screen, low to medium levels of ambient light washed out color and robbed both projectors of contrast and a sense of three-dimensionality, particularly in scenes like the spacecraft against a starfield in The Martian. Between the two, the TK850's higher brightness (192 nits on my 90-inch, 1.0-gain screen versus 119.9 nits) let it stand up to ambient light a little better, but neither projector is bright enough to deliver on HDR's promise with a big image in ambient light.
Note, too, that as with the HT3550, the TK850 includes an auto-iris, even though it doesn't yield as dark a black. It also shares being limited to a maximum 8-bit color depth with 3840x 2160, 60Hz signals. Using the downloadable ProjectorCentral 10-bit HDR Grayscale test animation, which verifies 10-bit processing from input to image, I saw some hints of banding with both projectors. However, I didn't see any banding artifacts with either one in any of the video and movie content I used for testing.
3D Viewing. Both the TK850 and HT3550 support Full HD 3D, and both deliver highly watchable images, with nicely saturated color, no crosstalk in my tests, and only the typical level of 3D-related motion artifacts for current generation projectors. Both were also bright enough for comfortable 3D viewing in the dark with a 90-inch diagonal 16:9 image using a 1.0-gain screen. Between the two, however, the TK850 is the better choice for 3D. Not only is the image noticeably brighter, but its black is more neutral, making the HT3550's black look reddish in comparison. The extra brightness for the TK850 also gives the image a bit better contrast.
Choosing between the BenQ TK850 and BenQ HT3550 is easy, and it matches exactly what BenQ recommends. If you want a projector for a dark room, and assuming you can light up the screen size you want with the HT3550's more limited light output, it is the clear choice. For SDR content, it will give you more accurate color along with darker blacks as well as excellent contrast and sense of three-dimensionality for the price. It will also do a remarkably good job at this price for HDR. And while it earns high marks on each of these factors straight out of the box, it's easy to tweak for still better image quality for those who want to invest the time to do it.
The TK850 can also be calibrated to give accurate color in a dark room, but without the same dark black level and contrast that the HT3550 offers. On the other hand, if you need a projector that will stand up to ambient light in a family room, its high brightness compared to the HT3550 is far more critical to producing good contrast and color saturation, particularly in darker scenes.
Although no projector in this brightness range is a compelling choice for watching HDR material with the lights on, the TK850's brightness gives it an advantage over the HT3550 for HDR as well. And both projectors deserve credit for how well they handle both SDR and HDR input with default settings. Between the two, in short, pick the HT3550 for a traditional dark home theater setting, and the TK850 to watch sports, TV shows, and movies in your family room.
For the comparison tests I calibrated both projectors using CalMan Ultimate software, an Xrite iPro2 meter, and a Murideo Six-G signal generator. We covered calibration for the HT3550 in detail in our standalone HT3550 review. Briefly, the projector offered good enough color accuracy out of the box that many, if not most, people would find it more than acceptable. More demanding users will find it easy to improve for SDR input with just some minor tweaking of brightness, contrast, Gamma, RGB gain, and color management settings.
For HDR input with the HT3550, I adjusted RGB gain and offset to improve grayscale and adjusted color management settings to improve color accuracy. But, as discussed in the standalone review, this improved some aspects of the image while hurting others. Whether you'll prefer the pre- or post-calibration image depends on whether you'd rather have better shadow detail in dark scenes (with the factory calibration) or better color saturation in brighter scenes. I had essentially the same experience with the second HT3550 sample I used for this comparison.
As with the HT3550, the TK850 offers a highly watchable image straight out of the box. The measured color errors for SDR input with default settings were much higher than for the HT3550, but still not enough to notice without measurements or a reference image to compare with. Using Cinema mode as my starting point, I couldn't find any color management settings that would get the error for most colors anywhere near the target of Delta 3 until I set Brilliant Color to 0, which also lowers brightness significantly.
Simply turning Brilliant Color off brought four of the six primary and secondary colors to the desirable level of accuracy. It also made it easy to adjust the remaining two. The only other changes I needed to make were to Gamma, Brightness, Gain, and Offset. After finishing calibration, however, I measured the brightness at only 429 lumens, and measured peak brightness for the image at 16.4 foot-lamberts (ft-L)—56 nits—on my 90-inch diagonal, 1.0-gain screen. This obviously defeats the point of opting for the TK850's higher brightness.
For HDR, I couldn't improve on the TK850's default settings. Adjusting the color management settings didn't have any effect on the color error for most colors, and turning off Brilliant Color, which is on by default, increased errors for both luminance and color, so you'll want to leave it on.
Beyond that, changing the TK850's HDR Brightness control had the greatest effect on both color accuracy and luminance. But because there's no standard for mastering content, different source material requires different HDR Brightness settings, and you'll generally want to pick whichever setting gives you the best looking image for what you're watching at that moment. I found the default 0 setting a good choice for most of the material I tested with. I measured the projector brightness in its HDR mode at about 1,400 lumens, and image brightness at 192 nits (56 ft-L).
Brightness. Using the widest angle setting for the zoom lenses, the measured ANSI lumens for Normal (full power) and Economic modes in each color mode was as follows for each projector:
BenQ HT3550 ANSI Lumens
BenQ TK850 ANSI Lumens
Other key measurements were as follows:
|Measurement||BenQ HT3550||BenQ TK850|
|Zoom Lens Light Loss||8%||9%|
|Brightness Uniformity (Wide Zoom)||63%||67%|
|Brightness Uniformity (Full Telephoto)||67%||67%|
|Lowest Measured Input Lag (4K)||47-51 ms||86.5 ms|
|Lowest Measured Input Lag (1080p)||60-61 ms||82-83 ms|
|Fan Noise rating (Normal/Economic)||30dB/28dB||30dB/28dB|
Fan noise. As the ratings indicate, both projectors offer virtually identical fan noise. Both offer the kind of steady sound that tends to fade into the background for anyone who isn't particularly sensitive to noise, and both are slightly quieter when set to Economic mode rather than Normal mode. Silence mode lowers volume a bit with both projectors, but not enough to make much difference. High altitude mode is loud enough in both cases that most people will want some form of acoustic isolation.
BenQ HT3550 and TK850 both offer:
- HDMI 2.0b, HDCP 2.2 (x2)
- USB Type A 3.0 (media reader and firmware upgrades)
- USB Type A (power only)
- USB Type Mini B (firmware upgrades)
- DC 12v trigger (3.5mm mini jack)
- IR Receiver (x2, Front/Top)
- Audio out (x2, 3.5mm stereo mini Jack, S/PDIF optical)
- RS-232 (D-sub 9 pin, male; for control)