Is it important that the pj lens is no higher than the top of the screen image? I understand that pj can come with two types of Keystone correction, Optical and Digital (for example the Sim2 HT300 (+/- 8deg and 13deg respectively), should Digtial correction be avoided if possible? Screen size I'm considering is a 6ft 16:9 screen (72"w x 40.5"h) with a small additional top drop (7" ?) + scr housing (about 6") that would put the top of the image at around 13" from the ceiling, roughly the same height of a pj lens so I'm sure that would be ok. But, would a screen with a top lowering mask to create a 2.35:1 image area (72"w x 30.6), be a keystone problem for the pj as its lens would be approx 10" higher than the image top? I think a bottom raising mask (to create the 2.35:1 from 16:9) would obviously prevent the top image from moving, but I've only come across top masking screens? Any ideas? n.