It certainly does, thank you kindly
would image height, essentially be the height of the screen?
Yes. So, using the above example (a PJ with 100% vertical lens shift): If you had a 90", 1.78:1 screen, the display area of that screen would be 44" high. You could place the projector so that the lens is aimed at a point up to 22" above the top (or below the bottom) of the screen and still be able to center the image on the screen.
(Note that maxing out the amount of shift is not necessarily desirable, and that that the range of shift would be reduced if you were also applying some horizontal shift.)
So as I'm understanding it, the projector projects the image upwards at around an angle of 26° ... so if I put the projector on a table say 4' high instead of 1' 6" as recommended on the Benq website then the lens shift would compensate for the fact that the image would be off the screen otherwise as it would be projecting too high?
Unless I'm mistaken (and I have been known to be mistaken
- PJs with lens shift always projects straight ahead, perpendicular to the vertical surface in front of them. The lens shift lets you "re-locate" the image.
- For a PJ with a fixed "angled throw", placement of the PJ is determined by the location of the screen + the angle of projection (or, conversely, the location of the screen is determined by the placement of the PJ + the angle of projection), and cannot be modified.