From Casino Royale, this image is overexposed to reveal the level of detail, in the roof. Under normal viewing, projectors' shadow details vary from the roof being essentially invisible on some projectors, to being able to see every individual tile.
For a different perspective, the images are identical, however the first one brings up an overexposed version (from the HD71) for looking at the roof (and other dark areas, including the trees). Second image gets you the Sony VW60, one of the very best 1080p projectors, when it comes to shadow detail. The VW60 sells for about four times the price of the Optoma.
Good, not exceptional black levels and shadow detail, but, many folks will be choosing the HD71 for its brightness first, and if you need that brightness, then, you also are likely operating in an environment, where there is some ambient light, and some shadow detail and black level performance, will normally be lost anyway!