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BenQ HT3550i 4K projector review: Sharp and colorful, needs more pop

The 3550i offers excellent detail and color accuracy, but weaker brightness and contrast leaves its overall picture quality short.

Geoffrey Morrison Contributor
Geoffrey Morrison is a writer/photographer about tech and travel for CNET, The New York Times, and other web and print publications. He's also the Editor-at-Large for The Wirecutter. He has written for Sound&Vision magazine, Home Theater magazine, and was the Editor-in-Chief of Home Entertainment magazine. He is NIST and ISF trained, and has a degree in Television/Radio from Ithaca College. His bestselling novel, Undersea, and its sequel, Undersea Atrophia, are available in paperback and digitally on Amazon. He spends most of the year as a digital nomad, living and working while traveling around the world. You can follow his travels at BaldNomad.com and on his YouTube channel.
Geoffrey Morrison
8 min read

Powered by 4K resolution and the inherent sharpness of DLP, the BenQ HT3550i home theater projector puts up exquisite detail. On a 100-inch screen I saw individual hairs, the specific weaves in fabric and wrinkles galore. It's also one of the most color-accurate projectors I've recently reviewed, with rich and vibrant reds, greens, blues and everything in between. These two aspects of performance make for a pleasingly realistic image. 


BenQ HT3550i


  • Excellent detail
  • Vibrant, accurate colors
  • Clean image with little video noise
  • Built-in Android TV streaming

Don't like

  • Not particularly bright
  • Mediocre contrast ratio

Compared to competitors in other ways, however, the HT3550i struggles. Its contrast ratio is on the low side of average, and brightness is far lower than many similar projectors, including the Optoma UHD30 and BenQ's own BenQ HT2050A. Without bright whites and dark blacks the image simply lacks pop. The HT3550i doesn't look bad in any specific way, it's just that its strengths -- including built-in Android TV streaming -- can't offset its weaknesses.

BenQ's HT3550i 4K projector is ready for its close-up

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Basic specs

  • Native resolution: 3,840x2,160
  • HDR-compatible: Yes
  • 4K-compatible: Yes
  • 3D-compatible: Yes
  • Lumens spec: 2,000 (ANSI)
  • Zoom: Manual (1.3x)
  • Lens shift: Manual
  • Lamp life (Normal mode): 4,000 hours

The HT3550i is a 4K projector, and every bit of that resolution is visible on screen. It's also HDR-compatible, but like all projectors, you shouldn't expect great things. 

That lumen rating is really the HT355i's biggest liability. 2,000 lumens is certainly not dim, and even just a few years ago would have been plenty. But in this era of ultrabright projectors, it's well behind. If it had a better contrast ratio this brightness wouldn't be an issue. However, it does not. We'll dive more into why that matters in a moment.

Like our Editors' Choice HT2050A, the 3550i is one of the few DLP projectors in this price range with lens shift. It's not a lot, but enough to make placement a bit easier. While it has a better zoom range than the like-priced Optoma UHD30, 1.3x vs. 1.1x, it's got a shorter throw. So to fill a 100-inch screen it needs to be around 8 feet from the screen, compared to 10 feet with the Optoma and most other projectors in this price range. In my case this means it has to go on the sofa, not behind it. BenQ seems to prefer shorter throws on its projectors, as the HT2050A was similar, but most of the other projectors we've reviewed this year didn't need to be so close. This isn't a huge deal, but if you've already got a projector mount, it's something to be aware of.

Lamp life is on par with this generation of projectors. The 4,000 hours in Normal mode improves to 10,000 in Eco. SmartEco mode, which varies lamp level based on the brightness of the content, improves this even more, to 15,000 hours.

Geoffrey Morrison/CNET

Connectivity and convenience

  • HDMI inputs: 2 (Both HDMI 2.0b)
  • PC input: No
  • USB ports: 2 (USB 3.0 and 2.5A power)
  • Audio input and output: 3.5mm out
  • Digital audio output: Optical (1)
  • LAN port: No
  • 12v trigger: Yes
  • RS-232 remote port: Yes
  • MHL: No
  • Remote: Backlit

The HT3550i has excellent connectivity options. Both HDMI inputs are HDMI 2.0, so you can connect two 4K HDR sources, if you so desire. I would assume most people buying a projector like this will have everything connected to an AV receiver first, with just one HDMI running to the projector, but the option for two is nice. 

There are two USB connections, which is pretty rare. Also rare is that one is USB 3.0, letting you connect and easily stream content from a hard drive. The other puts out 2.5 amps, again higher than what's available on other projectors. Most streaming sticks won't need this amount of power to run, 1.5A is usually fine, but once again, the option is nice.

For audio there's 3.5mm analog and a single optical output. The optical only outputs stereo, not 5.1. There are two 5W speakers as well.

Technically, you don't need a streaming stick because the HT3550i comes with one already. It's an Android TV dongle that installs inside the case, via otherwise hidden USB and HDMI connections, so you still have access to all the connections on the back. While convenient, the downside is you only get stereo audio, not surround. I don't think built-in streaming is particularly important in a nonportable projector like this one, however, since streaming sticks are so inexpensive and can be connected just as easily to a receiver or soundbar, which often give you surround options.

For home automation purposes, there's a 12v trigger and an RS-232 port.

The remote has a dim amber backlight that is far more pleasant to use in a dark theater than the Optoma UHD30's, which can double as a tanning bed for naked mole rats.

Geoffrey Morrison/CNET

Picture quality comparisons

While not 4K, and half the price of the 3550i, the HT2050A is our current pick for best projector. Since it did well against the UHD30, it's here again. Speaking of the UHD30, it's a direct competitor in terms of price and resolution. 

I connected the two 4K projectors using a Monoprice 1x4 4K HDR distribution amplifier, aka a "splitter." The HT2050A got its own source since it has lower resolution. 

We might as well start with the biggest issue: brightness. The HT3550i is half as bright as the other two projectors. Admittedly, those two are some of the brightest projectors I've ever measured, but even compared to far dimmer projectors, the HT3550i is no light cannon. I measured roughly 677 lumens in its Cinema mode, while the other BenQ and Optoma were around 1,600 in their comparable modes.

Usually a projector like this intentionally sacrifices light output for the better color and black level desired by home theater enthusiasts. This is, in fact, how BenQ markets the 3550i, calling it a "Premium Home Theater Projector." On the color front it's excellent, among the best I've seen in a DLP projector. However, the color of the HT2050A and UHD30 are nearly as good, and they're brighter. 

The 3550i's black level is good, but that's misleading. I measured a better black level than the UHD30, and about the same as the HT2050A, but it lacks the contrast ratio for that to matter.

The result, with all three projectors side by side, is that the HT3550i looks dim. On its own it doesn't, of course. Even 677 lumens on a 100-inch screen is fine, but when you can get far more light with only a little tradeoff in color, the HT3550i is starting on its back foot already. The contrast ratio, far behind the excellent HT2050A, is basically the same as the UHD30. 

Where the HT3550i fares far better is with, well, the other aspects of picture quality. As mentioned, the color is fantastic. The subtle shades and in-between colors are far more accurate and natural than most other projectors. Even compared to the HT2050A and UHD30, two projectors with great color, the HT3550i is just that bit better that it draws the eye. It's not quite enough to offset the contrast ratio, but it gets it closer than you'd imagine.

Geoffrey Morrison/CNET

The detail, too, is superb. Just as with the 4K UHD30, the extra pixels over the HT2050A are immediately noticeable on a large screen. This is what 4K was made for. Adding to this is a complete lack of motion blur. DLP is the only modern display technology that lacks any semblance of motion blur, and does so without assistance from black frame insertion or motion interpolation. 

Speaking of motion interpolation there seemed to be some mild smoothing, aka the soap opera effect, going on when I first set up the 3550i. There is the option for this for anyone who likes it, but I don't and wanted to turn it off. However, it was off. Disconcerting. After trying everything else, I turned on the motion smoothing, then turned it off, and that seems to have solved the issue. 

Another oddity is the projector's speed. No projector in this class is particularly fast. They all take a moment to switch between resolutions or frame rates for example. The HT3550i is especially slow, however, taking a noticeably long time to switch. Most of the time, this isn't an issue. Going from a menu to a show might take a few seconds longer than you'd expect. Watching YouTube, however, it tried my patience. YouTube ads are often a different frame rate than the video itself, meaning every 10 minutes or so (or whenever there's an ad), the screen goes black, then eventually resumes. It's long enough that if you're into whatever you're watching, you learn to pause at the end of an ad break so you don't miss anything on screen.

Lastly, there's the aspect of noise. Or specifically, the lack thereof. Not the fans, which are noticeable in any projector this size, but in the image. For comparison, the UHD30 is a very noisy projector. There's noticeable banding in bright highlights (clouds, for instance), and in shadows there's what looks like extra grain. The HT3550i lacks any of that. The image is noticeably much cleaner. This is somewhat less a win for the BenQ than it is an issue with the Optoma, but it's fair to give BenQ points for getting this right and looking far more natural.

Geoffrey Morrison/CNET


The HT3550i surprised me, but not in a good way. I was expecting the excellence of the HT2050A, just in 4K. That's just not the case. The less-expensive, lower-resolution HT2050A looks better overall in comparison, despite the HT3550i's superior detail and slightly better color.

Then there's the 4K resolution UHD30, which is the same price, offers nearly the same color and detail, but is 2.5x brighter. That projector also has a longer throw, for easier placement for many people, and only has slightly worse color. It does have more noise in the image, but I doubt most people will be troubled by that tradeoff. 

My recommendation? For most people, the BenQ HT2050A is the best value going. If you crave the detail of 4K and are willing to sacrifice contrast ratio (you really shouldn't) and tolerate some image noise and banding, go for the UHD30.

Or to put it another way, I've had these projectors in my theater/lab for months. After I was done testing the 3550i, I put the UHD30 back in and have been watching it ever since, and probably will until I need to send it back to Optoma. If it were my money to actually spend, however, I'd get the HT2050A.

Geek box

Test ResultScore
Black luminance (0%) 0.107Poor
Peak white luminance (100%) 75.21Poor
Derived lumens 677Poor
Avg. grayscale error (10-100%) 6,065.778Poor
Dark gray error (20%) 6,145.000Poor
Bright gray error (70%) 6059Poor
Avg. color error 2.479Good
Red error 2.621Good
Green error 0.948Good
Blue error 2.055Good
Cyan error 4.506Average
Magenta error 1.753Good
Yellow error 2.992Good
Avg. saturations error 3.06Average
Avg. color checker error 3.6Average
Input lag (Game mode) 155.1Average

Measurement notes

Color was obviously a major consideration for BenQ on the HT3550i. Its other projectors tend to be pretty accurate, but there was a naturalness to the 3550i that's pretty rare among projectors in this price range. All three primary and all three secondary colors are pretty much spot-on accurate. None were "perfect" but certainly close.

The trade-off for this, unfortunately, was image brightness. I measured 75.21 nits, which calculates out to around 677 lumens. For comparison, BenQ's own HT2050A did nearly 1,600 lumens and costs half as much (though is only 1080p). This was the lowest light output of any home theater (aka not portable or battery powered) projector in the last year. Even the Viewsonic PX727HD, which we knocked as being too dim, is 50% brighter.

If this was offset with a great contrast ratio the brightness would be far more forgivable. Single-chip DLP projectors like the HT3550i just don't have that, though. And even as DLP projectors go, the 3550i isn't great. I measured 693:1, a number so low I ran all my measurements twice, just to be sure. All the more surprising is that the HT2050A has the highest contrast ratio I measured in a projector in the last year.

The result, on its own, is not as bad as the numbers suggest, especially when viewing particularly colorful content. But as much as I love great color, it's just not as important to the overall attractiveness of an image as contrast ratio and, with projectors anyway, brightness.