Begin with image width, not the diagonal headline
Throw ratio relates lens-to-screen distance to image width. BenQ lists 0.69–0.83 for X500i and 1.15–1.50 for X3100i. For the same image width, X500i is the closer-placement candidate. A familiar diagonal size cannot replace the width needed for that comparison.
If the only usable location is a relatively distant shelf, the longer X3100i range may be the more plausible starting point. If the lens must sit closer, X500i deserves the first look. A projector with a more attractive feature list is still the wrong shortlist if its lens range does not fit the intended picture and position.
Height and distance are separate questions
X3100i also lists vertical lens shift. That provides a separate reason to investigate it when vertical image placement is awkward. It does not transform its longer throw into X500i’s short throw, or promise an arbitrary shelf height will work. Use the exact model’s placement guidance before fixing the installation.
Both specifications list optical zoom, but with different ranges. Zoom allows adjustment within a model’s optical limits; it does not erase the distinction between these lenses. Digital keystone correction is another function and should not stand in for confirming a plausible physical location.
The useful shortlist can be one model—or neither
Retain X500i for an appropriate closer position, or X3100i for the longer lens range and a specifically useful vertical-adjustment route. If neither fits, change the planned image or position before choosing between them. Then compare the other gaming features within the arrangement that actually works. The room should not be forced to follow the larger model number.
Sources & further reading
Editorial review date:
