Hopefully someone can tell me, because I can't find anything about it online. I'm starting my project really soon, and unfortunately I have to use things which I have found rather than bought, in general. This includes the bulb I'm using to test my idea.

THIS is the exact same thing as the bulb that I have, except mine is made by GE. Any idea how many lumens it is or how to calculate how many it would have? It was out of a microfilm projector, and is hella bright. I mean, it's not like it really matters, since I'm SURE that it's not powerful enough for the final projector I'm building, but it would be nice to know.

Thanks.

12 to 15 lumens/watt.

http://www.lrc.rpi.edu/programs/nlpip/ligh...performance.asp

80w at 12-15 lumen/w = 960-1200 lumens = the dimest projector in the history of DIY

Well, I try to be an underachiever. Like I said, I just hope it's bright enough to get my concept worked out, then I can look into getting something else. Reading up, it seems the cheapest way to get enough brightness is pretty much just buying a high wattage OHP and ripping out the bulb?

As an aside... I wonder how much I lose going through the LCD, two mirrors, and two fresnels?

a lot. LCDs are 5-8% transmissive so only 5-8% of the light that reaches the back of the LCD will make it through to the front. The loss from the fresnels and mirror are negligible compared to this, but they do cause losses. The mirrors might have a reflective % listed somewhere. These, combined with the fact that its difficult to focus light from the bulb through the triplet in the first place, and distance to the screen, is why 40,000 lumen bulbs result in 300 lumen projections

Also, you can get an m59 ballast for under $50. not expensive and pretty much guaranteed to give ample power unlike an old ohp.

So basically, even going on 1200 lumens... 90 or so lumens from the lens. That's sad.

Also... has anyone really tried those halogen work lights you can get at Home Depot, or are they just too inefficient and hot for a projector?

MH are 80-100 Lumens/Watt.
HPS is 100-130 Lumens/Watt but is yellow/orange rather than white
Xenon is whiter but doesn't have the efficency
Incandesent and Halogen are only 30 lumen/watt.

But at least it will give me a hell of a lot more light to work with a concept
than what I originally had.

80w original = max 1200 lumens
500w current = max ~15000 lumens

So that's why I asked. Got to start my PLOG, too. So since I changed, the
only thing this topic will be used for is bulb discussion, which is kind of
redundant. Thanks for the original answers, guys.