24PA on blue/green screen

[Norm Sanders]

I'm about to shoot a blue screen on 24PA (in about 2 hours), and just realized it may work better in Scene File 1 (29.97). Thoughts?

I thought I'd heard along the way that one works better than the other for picking up the blue/green, but can't recall which. For this particular scene, we're shooting a newscast that's going to be played back on a normal TV. Then, in 24PA, we'll be shooting a short film that will have the newscast on the TV (via DVD player). Since it's just coming out on a normal TV, and we want it to look as real as possible, I'm guessing we should shoot the newscast interlaced, like the TV stations do.

Thoughts?

 

[craigbowman]

Its not a colour thing at all. The only thing thats makes a quality difference is to shoot progressive rather than interlaced. So 24pa will work just fine.

Compositing tip 37 - Another tip for higher res if you're doing green/blue screen compositing is to turn the camera sideways on the progressive frame and then rotate it ninety degrees back to normal in post. The footage which gets matted is then 720p vertical almost as though you were shooting HD. (720 x 480 becomes 480 x 720) You can then composite into a high res background.

If you use a vector keyer like Ultra 2 with a locked down camera you can sample the background when nothing is in front of your screen and then later in the software send the empty image to the keyer. It will build a mathematical model of the difference between the empty scene and your actor(s) in front and build a vector key difference matte which works far better for DV than traditional keyers like Primatte or Ultimatte.