We write a lot about 3D on this site, but we admit we don't entirely understand the mechanics of the 3D filming process. (We believe it involves a series of tubes.) So Peter Jackson's video blog from the set of "The Hobbit" on the intricacies of 3D shooting is a pretty terrific crash course. Sure, this is all incredibly wonky, but if you sit through it you do get to see Martin Freeman and Elijah Wood acting and stuff. Also: This video will be especially cute in five years when 3D cameras no longer weigh 4,000 pounds.