Basis brightness question

[woody]

I would like to replace my 27" tv with a projector and a 4 by 8 foot screen. I need an image as bright or brighter than my standard 27" tv. I need some idea about what power projector I
need.

thanks,

Woody

 

[zzonbi]

A CRT TV has around 150cd/m2 luminance. Assuming a lambertian spread pattern this gives around 600lm/m2. You want about 3m2, then you need >1800lm projector.

With external lights on the contrast will be worse than standard TVs though, with ordinary screens at least.