calculating brightness, lux, lumen? - AVS | Home Theater Discussions And Reviews
Screens > calculating brightness, lux, lumen?
snowmoon's Avatar snowmoon 11:29 AM 11-07-2001
As a newbie I am trying to gather as much information as I can. One thing that still baffels me is trying to calculate actual screen brightness and contrast. I know it's impossible to tell with 100% accuracy before it's set up and calibrated, but I would like to know what type of ballpark I'm in. I have done quite a bit of reading but am still baffled.

The room is fairly well lit with much ambient light. I have already begun seeing how much light can be masked. I can also fit lighting behind the screen without much hassle. I am looking at a lt150 with a very short throw to a 57"x42" ( masked down to 32" ) wide screen. With an 800 lumen projector ~.3 lumen sq/in or 48 lumen sq/ft how can I calculate how it will compare to traditional viewing surfaces?

PQ is most important. I am also very interested in a wide viewing angle. From my understanding my best bet would be some sort of grey matt screen. I doubt with such a ( relativly ) small screen gain should not be necessary. The screen would be used almost exclusivly for movies.

Thanks,
Eric

Augie's Avatar Augie 11:44 AM 11-07-2001
My Screen Dimension Calculator can help you calculate how much light is coming off of the screen in foot lamberts. The spreadsheet formulas are based on information in this thread:

http://www.avsforum.com/avs-vb/showt...light=lamberts
snowmoon's Avatar snowmoon 12:16 PM 11-07-2001
WOW... thanks.....



Even taking into effect a .8 gain screen ( matt grey ) I'm still comming out with almost 38 ft/l comming off the screen. As far as posts here are evaluated that sounds encouraging.

I'm also thinking of backlighting the screen to take advantage of the eye's own ablility to turn grey into black.


Now if only I could justify spending $2200 this month.
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