This is just a matter of curiousity more than anything. Why are the RPP, or any cine lenses for that matter, so significantly larger than their photo counterparts?
Is this because Cine lenses are attempting to minimize breathing and distortion and thus require larger elements and housings?
Example, the Nikon 50mm f1.4 weighs 9.9oz and has a 58mm filter. The 50mm T1.8 RPP is 4.53 lbs and has a 110mm front element. Why so big?