Comparison with HC7900DW
Mitsubishi is also releasing the HC7900DW this year, which is similar to the HC8000D-BL in enough ways that a comparison is merited.
Just on the surface, it's clear that the two projectors share a common ancestor. Both use the same case design, though the HC7900DW is white while the HC8000D-BL is black. Both have the same lens with the same zoom and lens shift range. Both projectors have the same connection panel. They use the same DLP chip, and indeed most of the internals are the same, as well. The HC8000D-BL is sold through Mitsubishi's network of custom installers and resellers, while the HC7900DW is sold over the internet. So what's different about these two projectors?
Irises. This is kind of complicated. Both the HC7900DW and the HC8000D have an auto iris as well as another iris further back in the light path that is fixed (non-adjustable). But the HC8000D-BL has two additional irises, for a total of four. One is fixed, while the other can be switched from High Brightness mode to High Contrast mode, thereby emphasizing black levels or light output, depending on what the situation warrants. As a result, the specifications for brightness and contrast on these two projectors differ significantly.
Lumens. While both projectors use the same lamp, the additional irises in the HC8000D-BL bring light output down slightly. The specification lists 1500 lumens for the HC7900DW and 1300 lumens for the HC8000D-BL, but our own measurements indicate a more nuanced relationship. For example, the HC7900DW measured 659 lumens in Cinema mode with the lamp at full power. On the HC8000D-BL, that same mode measures 626 lumens with the iris set to High Brightness and 496 lumens with the iris set to High Contrast. So while output is functionally equivalent with the additional iris open, using the High Contrast mode results in a modest reduction of about 25%. The spec does not fully reflect this relationship.
Black level. Likewise, using the High Contrast iris setting deepens the projector's black levels significantly. The actual spec for the HC7900DW is 150,000:1, while the HC8000D-BL's own specifications indicate 330,000:1. Indeed, using the High Contrast iris setting does create appreciably deeper black levels on the HC8000D-BL. This is especially useful in a dark room, where deeper blacks make a real difference in image quality. More casual users in rooms with less stringent light control may not be able to appreciate the difference.
3D glasses and IR emitter. The HC7900DW uses "generic" 3D glasses, whereas most projectors are tied to their specific manufacturer's 3D eyewear. That said, the HC7900DW-compatible glasses we tested, made by XpanD, are heavier than most other 3D glasses. And, at least for me, I found that the glasses pinched the sides of my head enough that, over the course of a two-hour 3D movie, I developed a headache. That might be because I have a large head (according to my wife, at least, and also the one time I went to a hat shop), but it's still something to be aware of. The good news is that compatibility with generic glasses gives you some options.
The HC8000D-BL can use either those same universal glasses or Mitsubishi's special high-performance glasses, which deepen 3D contrast compared to the universal equipment. The high-performance glasses are slimmer, lighter, and more comfortable than the XpanD universal models, as well. If 3D is important to you, that might be something worth considering.
Neither the HC7900DW nor the HC8000D-BL includes either an emitter or glasses in the purchase price. If you want to watch 3D content, that's more equipment you'll need to buy. The emitter costs $99 direct from Mitsubishi.
Case color. The HC7900DW is one of the few home theater projectors to have a white case (the "W" stands for White) while the HC8000D-BL only comes in black. If you have a white ceiling, a white case can make the projector much less visible when ceiling mounted. Conversely, those placing the projector on a low shelf might find that the HC8000D-BL is less visible.
Marketing differences. The HC8000D-BL is sold through authorized resellers rather than over the internet. It also costs a bit more, at $2999 minimum advertised price compared to the HC7900DW's $2499. That price increase also includes a few substantive changes in support: the HC8000D-BL includes an extra lamp ($349 value), an extra year of warranty (three years versus two), and three years of express replacement service should something happen to the projector. The extra lamp alone justifies most of the cost difference -- the rest is just gravy.