No big surprise, stereographic 3D is here... Big time!

Posted By Heath Firestone on April 13, 2010 12:00 am | Permalink
I realize I'm not the only person who is at NAB trying to learn as much as I can about stereographic filmmaking, but there's so much to learn, and so many new things out there, that I'll at least give you my rundown of what I've found to be interesting with respect to this topic at NAB so far.

I was surprised by the number of 3D camera set-ups I saw at the convention.I had done a fair amount of research before coming, and thought I had a pretty good idea of what was out there.There, however, were a lot of companies I had never heard of, including an abundance of beam-splitter rigs, and side by side variants.This led me to wonder what the real options there are for actually managing the footage after it was shot. I headed over to Iridas, based on the suggestion of a friend who pointed out that they have been dealing with stereoscopic issues for quite a while, and explained to me some of the tricks they have discovered for reducing eye fatigue when cutting together a stereoscopic project.

One of the major contributors to the eye strain, which often leads to nausea, is when a cut where the point of convergence (where the two lenses are pointed at the same area, making it appear flush with the screen) has the subject of interest pushed back into the screen space, and in the next frame, the subject of interest is dramatically different, being projected out into the audience space.Our eyes have to work very hard to adjust to this depth change being so abrupt.This can be jarring, and distracting.

Iridas has some great tools and techniques for dealing with this by allowing you to adjust the point of convergence on a slider, which can be keyframed, which allows you to do the equivalent of a cross fade, but with depth adjustments, where the background image might move forward, ending flush as the other shot cuts in, beginning at the same position, and shifting forward to the position is was shot in.These are the kinds of unusual nuances which 3D editors are having to learn to make their projects not only watchable, but enjoyable. Despite being around in one form or another, for quite some time, it is a new frontier.

Another area, which I have found to be a great source of debate, is with regard to depth of field in stereographic composition.Having seen use of narrow depth of field in some scenes of Avatar, and noticing that if I tried to focus on these elements, I felt eye strain, it made me wonder if this is an artistic choice, in order to direct the viewer's attention to the key elements in the scene. The question I had, was: Is the immersive environment that 3D offers inviting enough that the audience is too busy looking around at things, and distracted from key visual plot elements, or, is this just a carry over from the film look days?

Since some of the scenes I am referring to in Avatar, were completely computer generated, any depth of field effects would have been added as an effect since virtual cameras don't have the same physical limitations as physical cameras.Overwhelmingly, experienced stereographers suggested that their preference was for crisp, clear images, allowing the viewer to look around a little and drive their own attention.But then, another friend suggested that the blurring of these shots on foreground images may have been done more out of necessity, in order to combat the negative effect which results from objects which are in the audience space, that extend out beyond the borders of the frame, since that causes additional distractions and edge issues.Blurring these borders and foreground elements can significantly decrease this problem.

There is much more to explain, and learn, but allow this to whet your appetite for more Stereoscopic 3D.