BenQ LH730 4000-Lumen Full HD LED DLP Projector - Manual (Page 13)

13 Positioning your projector
For example, if you are using a 120-inch screen, the recommended projection distance is 3895
mm.
If your measured projection distance is 4200 mm, the closest match in the
"Projection distance
(mm)" column is 4220 mm. Looking across this row shows that a 130'' (about 3.3 m) screen is
required.
To optimize your projection quality, we suggest doing the projection by referring to the values listed in the
non-gray rows.
All measurements are approximate and may vary from the actual sizes.
BenQ recommends that if you intend to permanently install the projector, you should physically test the
projection size and distance using the actual projector in situ before you permanently install it, so as to
make allowance for this projector's optical characteristics. This will help you determine the exact mounting
position so that it best suits your installation location.