I’ll start with Dark Shadow Detail. No problems here. Look into the dark woods, on the right, or the bushes behind the the tracks on the right side, and there’s plenty of detail. (Bond night train scene)
And it’s very visible, but that, as always, is in part because projectors without really dark blacks naturally have near blacks that are appropriately brighter, and therefore easy to see.
Of course, there are other great dark images here for your consideration. The City of a Thousand Planets (Valerian) dark photo may end up being a new photo for comparisons, one that is 4K with HDR, since 4K with HDR behaves rather differently than all our good old 1080p content which all lacks HDR.
Black Levels are a disappointment, as they have been on every single chip DLP 4K UHD projector we’ve reviewed, except the far more expensive HT9050, and that projector, while better at producing dark blacks, still wasn’t great. It it was a definitely step up from entry level/near entry level, where this BenQ fits in just fine with its competitors. There's a whole sequence of labeled greyscale and overexposed shots of the Bond train scene for comparison. The last two, Epson and Sony, are over $1000 more, and $4999, but are good examples of step up performance on black levels.
Of course, to get a dramatic improvement in black levels, you’ll probably need to spend close to an extra $1,000 at this time.
If you are used to projectors with what I have long called “ultra high contrast” projectors, such as the Epson UB and higher, JVCs, Sony HT projectors with dynamic irises, and some really high end projectors we don’t get to review, then the HT2550 will be a real disappointment in this area.
That’s why I tend to think of most of these projectors as “home entertainment” in that they will appreciate being in a really dark room – even near pitch dark, but the projector doesn’t produce those deep blacks, instead rather medium dark greys, on very dark scenes.
For all of my "complaining" most of my friends don't notice. Friends over for Game of Thrones thought the picture was pretty great, overall.