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

[Yahmoncool]

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?

 

[Yahmoncool]

no one knows?

 

[superdaveumo]

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]

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!

 

[justme]

brightness

Hi, been away for a while.

As I understand it, when all the rest is aligned well, the brightness is less as the size of the displayed image increases, (inversely proportional comes to mind but I'm not sure that's correct).

 

[nexarius]

Yes, that's fairly obvious. What is being discussed here is whether or not the size of the LCD has a significant effect on it.

Yes, the brightness of the image displayed would be inversly proportional.

 

[cbm5]

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.