Estimated brightness

[MystikalMethod2]

Hey everyone,
Everyone says that about 5 percent of the light goes through the lcd (with a good reflector that is) I did the math and with an initial bulb thats an 1800 lumen projector... What would you guys estimate your projectors are near compared to a store bought LCD projector? I just dont think 1800 lumens sounds correct...
Thanks in advance

 

[jcbklyny]

You'll hear alot of phony numbers shouted out on this board... they're all wrong! Sorry guys... but there no possible way to know exactly how much light is actually passing through the LCD with DIY projectors.

There are just too may variables involved.

 

[MystikalMethod2]

I didnt ask exacly, I just want to know (on a scale of lumens peoples projectors are....Thanks

 

[Lifter]

I'd say 10% would be the average. Makes sense. And it is possible to do a side by side comparison to a manufactured projector. Not that anyone's done that which I'm aware of.

 

[MystikalMethod2]

Thanks man, youve helped me out a lot

 

[verbose mustafa]

I do not think ansi lumens is measured by taking 10% of the light that goes through... Any one have a clue?

 

[jcbklyny]

ANSI lumens is the amount of light ON SCREEN... not the amount of light that passes through the LCD....

Which is why, like I said you cant use the 5 or 10% numbers floating around the board...

 

[verbose mustafa]

ANSI Lumens The measurement of brightness at the screen of a projected image. An image of 1 square meter is divided into 9 equal segments. Light is measured at the center of each segment and then averaged. This is the brightness measurement used in all-in-one LCD projectors.

Aha! From what i read above, ANSI lumens is not just 5% of light goes through.

 

[Mavmesa]

Lumens are determined by the light on screen. I have started using my Minolta light meter to test various reflector designs verses no reflector. Unfortunately, it figures light in terms of F stops. So, how much increase is a change from F-5.4 to F5.7?
20%?

Ken