Calculating ANSI lumens

[Morien]

Hey,

is there any way of telling how many ansi lumens there will be in a projector?
like a formulae or something?
say if there's a 25,000 lumens MH light, how many ANSI lumens would there be?

Thanks

 

[Lifter]

Usually about 10%.

 

[Morien]

Hmmm, ok thanks Lifter.

 

[Crash]

10% is a pretty good starting point.

However you also have to factor in the loss of light from your reflector and other things, really 10% is a high guess. You may be able to get that good of efficiency but likely will not... I'd say 5% would be a better general guesstimate.

 

[verbose mustafa]

10 percent is very giving. I would say about 2-4% of light goes through.

 

[Tekker]

let's say it's average 5% by a DIY, what is it by a manufactured build projector, just to compare ?

And is it ALWAYS better, the more lumen the better picture, cause you can overlight the screeen I guess. Like using a 1000watt bulb is it usefull EVERY time, I guess not ?

 

[verbose mustafa]

Read the following thread. It is a little off topic, but explains about the amount of light passing through the lcd.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=10231

 

[Video Freak]

Great Just wat I was looking for, man so Now I can see whay they can Ctick it to us😱 on the projector bulbs at 400+, hummmm any thoughts if 2 400 watt MH will be too hot to retrofit into a OHP?