This Optoma has a 1.2:1 zoom lens, which is typical for DLP projectors. This provides limited placement flexibility. We expect most owners will ceiling mount the projector.
To fill a 100 inch diagonal, 16:9 aspect ratio screen, the HD806, as measured from the front of the lens, can be placed as close as 13.4 feet to the screen, as far back as 16.1 feet, or anywhere in between.
The limited placement range, and the lack of adjustable lens shift, preclude using the HD806 projector on a shelf in the back of a room, so typically, this projector will be ceiling mounted.