From Space Cowboys, this image of Clint is in a very dark room only illuminated by a down facing table lamp.
the Optoma HD71. For comparison, the image is the Epson Home Cinema 720. The Optoma image is just a touch darker, and if you allow for that you quickly realize that they are similar in performance, looking at the window shades (the whole right side). If anything, the HD71 has a slight edge here.
The next one is the Panasonic PT-AX200U, on the same image, in this case, the Panasonic is definitely brighter than the other two, but even more so, you can see more shadow detail on the Panasonic than the other two, and, for that matter, it is producing slightly blacker blacks. The white in the blinds is more visible, and you far more easily make out the reflection from the glass behind the shades, right above his hand and bottle!