Thursday, July 8, 2010 C3DV UPDATE: Cam Rig Tests

I finally had a chance to try out the 3D HD video camera rig that we showed off here in the update from the annual conference (Field Notes from Atlanta: Collaborative 3D Video Launch). Once you get your head wrapped around the fairly straight-forward set up and achieve a viable angle of parallax (to emulate both the distance between your eyes and the convergence of their individual sight lines)--which you do simply by screwing the 2 cameras close together on the metal bracket--it's remarkably simple to shoot and get very usable results for anaglyph 3D. The only thing you have to manually do to insure synchronicity between the two cameras is to "slate" each shot. In traditional filmmaking, slating (or clapping) is used to synchronize the sound and image recording devices (which is more of a film than a video thing from back in the day). Because the cameras don't start running at exactly the same time, the key issue for double camera 3D shooting is being able to synch up the two videos. I didn't have a slate handy, which would be convenient as you can write all kinds of useful info on them like scene and shot #, etc. (the cameras default file naming systems are not relevant to one another so sorting out lots of video files after you've finished shooting can be a bit of a mind bending experience that would be much relieved if you had an onscreen image at the head of each shot that made it obvious which two files went together). So I had to improvise and just clapped my hands together in view of both camera lenses in order to establish a synch point. (I've left Omar's clap in the second video so you can see a demonstration of this technique.) So, that's pretty easy to work out and you can quickly start shooting with a rig like this for 3D.

The slight bit of trickery comes in after you've copied the video files from the cameras' memory cards onto the computer you plan to edit with. Unfortunately, these lower-end HD cameras are not designed to create truly editable file types (and don't allow for the option to save at different codecs or file types). They default to .h264 files which are designed for exhibition (like a quick upload to YouTube) but not for editing. Pro edit tools like Final Cut and Premiere hate these files and will give you much misery (as they did me) when you try and cut with them. So, the little bit of trickery, and a bit of a pain, is too convert them before you edit with them. I used MPEG Streamclip to do this (
free download) and was able to fairly quickly render them as useable .mov files for Final Cut. MPEG Streamclip is a fairly robust tool so I also trimmed the heads of each shot to the clap/synch signal and reduced the pixel size before converting the files. Then I imported them into a Final Cut project and simply laid them both out to start at the clap. I then created a channel setting in the color effects for the red and blue filtration which I saved as 2 favorite FX to be reused on all subsequent, anaglyph projects. This was simple to do and will be demonstrated in an upcoming post, complete with the shooting setup, tech info and tips, file conversion and final compression for upload of HD video results to web. For now, just enjoy these very short initial samples from the camera rig, which are really just a test to see if what was initially an idea about how to do this in a fairly simple, accessible and inexpensive way could work. I think it did. And once I put together some more tests and an easy to follow tutorial, you'l be able to borrow this rig (or make your own) and try some on your own. Warning: shooting in 3D this way is pretty addictive. It's hard now to think of a good reason NOT to shoot every Clubhouse video idea in 3D.

Test 1 is just 3 quick shots of some basic skateboarding into the cameras. I'm not quite satisfied by the effect as I was hoping to have the skater (Omar) and board feel more like they were coming right at you. That's going to take a little more work to figure out but we have a few ideas about how to do that. If it works out, I'll share that info in a follow-up post.

Omar Skating the Bronx in 3D - Cam Rig Test from Computer Clubhouse on Vimeo.


Test 2 is a quick improvisation with the tripod (all 3 legs pulled together) basically just dangled out over the bridge roadway as we were walking back from the Bronx where we shot the skating samples. I realized that the structure of the bridge and the traffic moving toward us could make for some interesting 3D so without much thought I just got a quick clap from Omar and extended the rig out into the traffic while slowly moving it around to take in views in a variety of directions. We slowed this down in Final Cut so that viewers wouldn't get too nauseous watching it.

Samsung Cam Rig test 3 or Alien Encounter on Macombs Dam Bridge from Computer Clubhouse on Vimeo.

In both cases, the 3D is pretty good but still veering towards the diorama look, where all the action seems to be taking place behind the plane of the monitor. In the still tutorial we were able to achieve the effect of objects protruding out from the screen (Making a 3D Anaglpyh Image) and I think that we will be able to achieve that here after some more tests. Stay tuned.

P.S. We originally thought, and wrote about, using an anaglyph plug-in for Final Cut to render the 3D effect, but after monkeying around with it we realized that it was just too inflexible for our purposes. Making the red and blue channels and shifting the video layers manually is easy and affords a much greater range of alignment.

Leave your comment 0 comments:

Post a Comment