Legalities of doing something like this aside, this concept by [MadSci labs] gives some insight into how one would go about recording a 3D movie in 3D. Probably many of you have wondered if this could be done, but they took it one step further and actually made a device capable of doing just that.
[MadSci labs] solution involved taking some 3D glasses home from a theater, cutting them to size, and taping them to a HTC EVO 3D phone. Each lens piece was taped over a different camera lens to separate out the two 3D elements needed to produce a stereoscopic image. Their experiment was successful, however some loss of quality was experienced. Because of this, we’re not expecting to see a lot of in-theater movies pirated this way, but given a more professional-quality build, you never know what will happen.
You can see the “results” of their experiment after the break. As it’s not in 3D, it should give you an idea of what is going on.