Black Levels & Shadow Detail
While I have said repeatedly, don't even think of these projectors as real home theater projectors, because of their overall picture quality, it turns out they are actually fairly respectable when it comes to black level performance. This is likely due to all the pico projectors we've seen, using either a DLP or an LCoS chip. Both technologies have particularly good native contrast, and therefore allow for very decent black levels. To put that in perspective, the little Optoma (DLP), has better black level performance than most larger LCD projectors. From a spec standpoint, the Optoma and Aiptek both claim 1000:1 contrast (a step up from the usual 400:1 to 600:1 found on most LCD business projectors). The 3M doesn't publish a contrast spec, but should be in line with the other two.
Shadow detail is a different story. All three projectors are losing a significant amount of shadow detail compared to any home theater projector. As a group, the projectors all look to contrasty. The one that loses the most, is the Aiptek, which as you can see in the Gandalf image above, loses almost all detail in dark areas (note the dark object in the lower left - top of his staff?). The difference between the detail on the 3M and the Aiptek is dramatic, with the Aiptek losing. Again, however, if that clip is downloaded into the memory/media player of the Aiptek, you can reduce contrast, increase brightness, and drop color saturation, and then the final image is far closer to the 3M image than the original unaltered Aiptek image.
All considered, color performance and picture quality leave much to be desired. Yet, for not critical viewing - (aka having fun with your pico projector), these projectors really aren't as bad as I tend to make it sound. I've shown them to a lot of folks, and everyone thinks their cool. They realize that the picture quality isn't that great, but they still like playing with them.
Whether you have a serious application, really need the smallest possible projector, or just want a new toy, pico projectors may work for you. It's your call. Keep in mind, however, these are essentially first generation products, and their overall picture quality reflects that. Future pico projectors are likely to have better color, and more image controls, but of course by that time, some of the novelty may have worn off.