hi,
just a quick question, is it possible to raise the screen by just angling the triplet up say 10o then applying the needed keystone correction?
thanks

You would have to lower the lamp the same % and adjust the fresnels slightly.

Whoa there.

Do you mean just angling the triplet, or do you mean moving it's location?

Just angling the triplet will only make your focus go off.

If you mean moving the lens to alter the projector's principal axis, then what you mean is lens shift, which you can do -- within limits.

I just meant angling the triplet up a bit whilst keeping it in the middle of the box.
Have abondoned this idea as don't really want to get too involved with lens shifting so am using a vertical design but using an angled mirror to focus on the angled triplet(seemed easier to me at first but will see how it goes).