Last week I did a shoot at DPI with my friends Ariel Efron, Andrew Schneider and Katherine Behar. I went ahead with the setup that I previously described - which is two Panasonic DVX HD cameras shooting through a piece of non-glare plexiglass, with two overlapping retroreflective screens providing the background.  Both cameras were mounted with green led rings to provide a green screen effect.

 The plexi has a matte coating which reduces reflected light, which I thought would be essential in order to prevent the lighting being seen in the camera lens.  However, I discovered that this is more about angle and position of lights and camera than anything else, and the matte non-glare coating makes everything look slightly soft-focus - almost like someone has put vaseline on the lens.  Not what I wanted, but not a disaster, either.  It actually makes the HD video look a little softer and grainier and more like film, so that's really a question of aesthetic.

I tried using a polarizing filter to reduce reflected light, but of course, this just prevents the light from the led's bouncing back and providing a green background, so that was a bad idea.

Anyway, I spent the weekend working in After Effects with the content that we shot. The key is an easy pull (using Keylight), however, there are some slightly dicy shadows around some edges.  This is because of the angles of the lights that were necessary to avoid reflection.  However, I think it's manageable in this context, although would need a lot more work if it was for broadcast.

What has been a bigger problem has been synching up the two cameras point of view.  In my first test sketch, I had different framings for the cameras, which worked very well.  I should have stuck to this setup, but in my desire to keep pixels at a highest possible level, I changed the framings.  This has left me keyframing motion masks, which is something I dont' really have time to do.  

All this while working down at the Liberty Science Center every day to finish up the installation there (see earlier blog post about sensors on ceiling). It's working very well, and I'm pleased with the solid tracking that I've achieved in a space with such uncontrollable, dynamic lighting.