I am going to be blowing up to 35mm a 2 minute stop-motion animation I captured with Dragon Stop-Motion. The photo files were shot in Nikon RAW 4288 x 2848. I converted them to TIFF files in 2K, 2048 x 1360, in order to work with them in After Effects in a size that my machine could handle. The compositions are also set to 2048 X 1360 (square pixels). I have nearly finished keying the shots and doing the animation and compositing.
My next step is to prep them for a 35mm blow-up. My first question for you guys is: Does anyone know if it is better to keep the image files at 2048 X 1360 and have the lab matte them down to 1:1,85 aspect ratio or do it myself? (And do labs need a small margin of error with respect to the pixel dimensions during the blow-up?)
A second question is: How can I make a composition that presently has a 1:1,50 aspect ratio (2048 X 1360) into a 1:1,85 aspect ratio for the 35mm blow-up? I animated the film with a simple 1:1,85 reference that I made myself to give me an idea of a 1:1,85 frame, but it was by no means completely accurate.
In FCP you can just add a simple 1:1,85 matte effect to give you a very accurate frame reference but I have yet to see one with After Effects. Maybe I'm just blind. Does anyone know if one exists and where can I find it?