Am I thinking about this backwards? Is the light output greater with a smaller LCD?

Yahmoncool

Member
2005-04-26 5:47 am
SC
I am either going to get a 10.4'' LCD or a 15'' LCD... will my lumen output be greater with the smaller LCD? My thinking is that all the light will be 'funneled' into a smaller image... making the output greater?

Is this correct? Or is is the other way around?

Also - how much does placing an LCD panel over the lamp reduce lumen output? By half?
 
I would think that using a smaller LCD would create a brighter picture. But how much brighter? Could be undetectable. I would think it's not significant.

After passing through the LCD, the light is reduced to about 20% (ish). Please correct me if I'm wrong. But, I do know that the LCD will dramatically reduce the light output.
 

nexarius

Member
2004-10-04 9:39 pm
No. If the LCDs have fresnel lenses to fit them, then size isnt going to affect brightness very much. If anything, I would suspect larger LCD making for a brighter picture.

And the figure is around 10-20% for light transmittance through an LCD.

There is a load of information on this in a recent thread at Lumenlab in the Customers forum, so if you guys are customers there (which you should be), then check it out!
 

cbm5

Member
2005-03-14 12:47 am
Arkansas
A smaller LCD will intercept less angle of the light sphere coming from the bulb, assuming you use the same fresnels for 15" displays and cut them down. If you had a fresnel with a shorter focal length, you could move it closer to the bulb and intercept more of the light sphere. An LCD 1/4 of the size of a 15" display, at the same distance from the bulb, will capture about 1/4 of the amount of light. For small LCDs you should always plan to use a good reflector and precondensor.