I have made videos that are 1/10 of a sec out and they look bad, we are talking go pro here so it is a lot of close up fast moving stuff and the images get out of sync. 1/25 of a second out what I aim for. I have noticed that the shutters are out of sync so I can never be spot on, potentially up to half a frame which is in theory only 1/50 sec.
I guess synced shutters is good for still but we just do screenshots out of the main movie, in fact printed 3d stills are a whole letter better/cooler than the 3d video.
I guess if you're making a movie you have more time to edit etc.
Just going from my observations, we used a click as a sync point and that sound carries over 2-3 frames, mainly that is close enough, but once we get into the thick of the close up action the frames are slightly out of sync and you lose the effect. only slightly, but it takes a split second to get it back and it sort of ruins the effect. it is a whole heap better if you spend a couple of minutes visually checking and shift one of the streams by a frame or two to get it perfectly aligned.
Personally I am still unconvinced by 3d, if they ever make a tv set that allows mass viewing but doesnt need glasses then it will be a goer, but is that possible? i guess they can get to the moon so anything is possible To quote my favorite film critic 'think of your favourite film, would it have been any better in 3d?' the answer is probably no (unless your answer was avatar).
There is definately a place for 3d, but hey there always has been, I remember watching nightmare on elm st, jaws, 3d comics and the new 3d tvs are certainly impressive, maybe once the price drops I will buy one.
Still get the impression that hollywood largely sees 3d as a mixture of anti piracy and gimmickry.
But Avatar did show us that it can be quite cool