Epson 51c - Manual (Page 13)

8 Setting Up the Projector
Use the figure below as a guideline to help you determine how far
from the screen to place the projector. Your image size may not exactly
match these sizes; its actual size depends on whether you have adjusted
the image size setting (using keystone correction or the
Wide/Tele
button).
When projecting from a table, the ideal arrangement is to set the
projector flat on its surface with the base of the lens at about the level
of the bottom of the screen. This delivers the best-looking picture.
If you have to raise the projector by adjusting its feet (described on
page 30), you’ll need to square-up the sides of the image by pressing
the
Keystone button (see page 31).
If you’ll be projecting from overhead, you’ll get the best-looking
picture by mounting the projector upside-down, parallel to the
ceiling, with the bottom of the lens level with the top of the screen.
(You’ll also need to select ceiling projection mode in the projector’s
Advanced menu; see page 44.)
4 ft. 8 ft. 40 ft. distance from the
screen