The 3D rig I used for a Civil War Battle Re-enactment 3D video
I used two Lumix GH-2 DSLRs to shoot 3D video. In this configuration, the lens centers are spaced about 6 inches apart which means that primary subjects need to be at least 15 feet and preferably 20 feet away from the camera to avoid 3D eye strain (convergence going bonkers).
The cameras are screwed into a rail made of aluminum using 1/4-20 knobs picked up at a local hardware store. Audio is recorded using two shot gun mics (bought off EBay, and yes, one has a homemade wind muff) and feeding into a factory refurbished Beachtek audio mixer which connects to one of the cameras. The shot gun mics make a HUGE difference in audio quality. Unfortunately, for the first battle I had left my XLR mic cables in my car so recorded the good audio only on the 2nd battle.
The six inch lens spacing is okay for outdoor landscapes and events where the subject is typically 20+ feet away. But experimenting with the Kodak Playsport cameras that I picked up used, I find the 3″ lens spacing produces a much more pleasing 3D effect. Probably not a big surprise, after all, what’s the spacing between your eyes? Probably not six inches!
But the GH-2 does have some nice features – like being able to align the zooms on the two cameras pretty easily (and good enough). Plus for video, the 14-42mm stock lens provides multiple focal lengths. Not only the 14-42mm range, but also the “Extended Telephoto” mode that crops the 1080 field out of the full image sensor, roughly doubling the focal length at 1080p.
Time permitting, I hope to produce a tutorial on shooting 3D with ordinary consumer cameras. From what I have seen, consumer oriented 3D “all in one” cameras do not deliver the video quality that interest me. While its a little more work, two consumer cameras can deliver surprisingly good 3D results, and results that are clearly better than the “all in one” approach. Plus, I can use external mics which most low end cameras do not support.
In theory, we are supposed to time synch the two cameras for precise frame alignment. But for most activities and viewing on the computer monitor or even the HDTV, frame level synchronization while editing seems plenty adequate. I am not shooting for the local movie theater or IMAX screen!
How do I synch the two cameras? I just snap my fingers to put a pulse on the audio tracks (or in the case of the Civil War battle, musket fire works quite nicely too). Then in the 3D editing software, I use the audio track pulses to align the video segments.