Quote:
Originally Posted by
dbals 
i agree with the fact that a curved screen "can" fix pin cushioning if its an issue on a anamorphic lens. however, Im still debating if a curved screen has some considerations when being used with a zoom feature. mainly because if the projector is placed closer to the screen or the apature has to be more open your using more of the glass and the natural curve of the lens comes into play more.....and that could cause some of those edge distorsions. a curved screen could fix that in theory. i would also think that if the projector is at the tail end of its throw ratio its using only the middle part of the glass and the curve of the glass has less if any influence on the picture.
my issue is i want the biggest screen i can get but the projector has to be as closely mounted to the screen as possible which means its going to be zoomed all the way open and that curve of the lens might have some influence on the picture.
I have an Epson TW5000 (7500ub?) which is 3.8m back (~12.4') from a 120" diagonal scope screen. I use the zoom lens almost at its absolute maximum (well I guess I'm actually using the widest angle, rather than the telephoto). Using this much glass, the only issue I notice is that focusing is more difficult, made more-so by the manual focus ring. By this I mean that focus is not 100% uniform across the whole screen. I don't have any distortion when the grid pattern is on the screen so a curved screen would definitely create issues in my setup.
So yes, light is passing through more of the lens, but the light isn't being stretched out like it is in an anamorphic lens either so the chance of severe distortion being introduced (enough to require the use of a curved screen) is minor. At least from my experience with the Epson at closest throw/max image size.
I'm a photographer as well and use many wide angle lenses which means I spend half my time correcting for distortion in photoshop. I would spot it and it would annoy me if distortion was a significant issue with my projector. Not at all saying that my situation will be the same for everyone, and the 61000 may have a different lens, but the zoom ratio is the same IIRC.
