I talked to Jim Delabarto about the "smeared" field lens you sent via IMAX. Jim said he responded to you and IMAX by e-mail several months ago, with the analysis of the material. The "smear" material was analyzed as a plasticizer that is used in the manufacture of polyurethane rollers. The gelatin film emulsion evidently picks up minute amount of this material, and the very high radiant energy and hot field lens drive it out of the film so it deposits on the field lens. This has only been reported when using the very large lamps.

As you know, one or both "eyes" of 3D films are shot with a mirror in the optical path of the camera, "flipping" the image orientation, whereas 2D films are shot with the negative emulsion toward the lens. So a 2D contact print will "read" correctly through the emulsion, and project with the emulsion toward the lamp (rotor). A 3D print will have the opposite orientation because the negative was exposed through a mirror. The only way to correct this would be an extra optical duplicating step or printing through the base, both of which reduce sharpness.