Brightness is very important in projectors, the higher the brightness (ANSI lumens) the easier it is to see in bright environments and a quality image given. The level of brightness required is also dependent on the size screen wanted ? for a 60? (diagonal) screen 150 to 300 lumens is sufficient in a dark room, up to 150? screen 700 ? 800 lumens and for a 300? screen anything from 1200 ANSI lumens.
Changing the Brightness makes the whole image lighter or darker.
Lighten sor darkens the output image data.
The thing that makes darkness go away, measured in lumens on a projector.
A scanner function to lighten or darken the output image data
Detailed observation cannot be performed with a lens that produces a dark image.