# Inverse square law and how it applies to projectors

I was adjusting the position of our projector on our SLA printer and have found that at further distances our models have less adhesion.

Does the inverse square law of light apply to DLP projectors?

I am aware that the inverse square law only is 100% applicable when you have a point as your light source, but I assume close to the same holds constant for other real world light sources.

Any ideas as to to what extent this is true or not?

• Consider to spell out acronyms. – Qmechanic May 7 '20 at 1:37

The power the projector uses to light up the interior of the square stays the same, so the power per square foot of image goes as $1/r^2$.