CurtPalme.com Home Theater Forum

[Spanky Ham]

http://homecinemaguru.com/?p=966

Jeff Meier (umr at AVS) did a test of ANSI contrast and his very well treated room. I think he said there is nothing in his room that is lighter in color than a coffee bean. He says that the room will give a percentage of max ANSI. Here are some of his results:
White Squares - 15 fL
ANSI Leakage - 0.064 fL
Room Reflection - 0.036 fL

On Screen ANSI 150:1 = 15 fL/(0.064 fL + 0.036 fL)

Here is the math for my room with a 800:1 ANSI machine...

White Squares - 15 fL
ANSI Leakage - 0.019 fL
Room Reflection - 0.036 fL

On Screen ANSI 270:1 = 15 fl/(0.019 fL + 0.036 fL)

ANSI leakage is the light in the black square from the pj.

By my math, a CRT in his room would look like this:
White Squares - 15 fL
ANSI Leakage - .12 fL
Room Reflection - .036 fL

On Screen ANSI 96 :1 from a 150:1 max

Darinp has mentioned that a high gain screen like a High Power keeps a greater percentage of max even in a lightly colored room.

I have thought about this in the past and believe that outside of a high gain Torus or a retro reflective screen like the High Power the best thing to do would be to make a shadow box around the screen with black velvet.

[WanMan]

I agree with the black box idea--regardless of projection technology.

[tse]

I was recently measuring the ansi checkerboard and was thinking "why are the numbers so crappy?". Then it hit me, I was wearing a white shirt. Not recommended for best readings.

Scott