Ignore my poor art skills.
Full Version: 2 bulbs?
Has anyone ever tried mounting 2 400watt bulbs in one projector? Would this double brightness? (title is supposed to read Dual 400watt bulbs)
Ignore my poor art skills.
Ignore my poor art skills.
You could add 4 hundred bulbs and it wouldn't increase brightness.
The DIY projector works by using a single light as a point light source. The first fresnel collimates that single point of light over the entire Lcd. Then the field fresnel narrows that light back down to fit in the triplet.
If you don't have that single light right in the middle of the fresnel and lcd and triplet you will lose a lot of light. Now move it 2" up and add another light 2" below that and you probably wouldn't even see much of a projection.
And before you ask. No you can't use 2 lights and 2 fresnels. There is no way to get the light spread perfectand then get it back through the triplet.
The DIY projector works by using a single light as a point light source. The first fresnel collimates that single point of light over the entire Lcd. Then the field fresnel narrows that light back down to fit in the triplet.
If you don't have that single light right in the middle of the fresnel and lcd and triplet you will lose a lot of light. Now move it 2" up and add another light 2" below that and you probably wouldn't even see much of a projection.
And before you ask. No you can't use 2 lights and 2 fresnels. There is no way to get the light spread perfectand then get it back through the triplet.
What about 1 bulb directly behind the other in the middle?
The only person who was somewhat successful in using multiple lamps in a projector was weldonjb - and he was using xenon lamps with a very small arc.
Regardless of how you mount the 400W'ers, it isn't feasible.
Regardless of how you mount the 400W'ers, it isn't feasible.
QUOTE (Canadianfreerider @ Jun 22 2008, 07:36 PM) 
What about 1 bulb directly behind the other in the middle?
No because one lamp would be to close to the rear fresnel and one would be to far away. You have to have the lamp at the right focal length to work.
Really almost everything imaginable has been tried.
Do google searches for everything you come up with and you will see.
Like: dual lamps site:www.lumenlab.com/forums
Not saying it's practical, but arizonavideo tested a dual lamp setup, and at first glance, it doesn't look like a bad idea.
It's late and I'm off to bed so I didn't get a chance to read past the first page, but it at least looks like a good starting point.
http://www.lumenlab.com/forums/index.php?s...c=8219&st=0
It's late and I'm off to bed so I didn't get a chance to read past the first page, but it at least looks like a good starting point.
http://www.lumenlab.com/forums/index.php?s...c=8219&st=0
in theory, putting the two bulbs in one giant reflector, with a condenser lens covering the entire front of the reflector should allow you to use two bulds ad long as the condenser is centered with the fresnel. as to rather it will enhance image brightness. It might, but not by enough in my opinion to justify spending the extra cash on multiple bulbs in the first place. keen in note however, that this could serve as a good solution to using led's
I think the 720mm fl fresnel that I scraped from a old RPTV has three focal points, one for each CRT. Whenever I tried to test the fl I would see three images.
You just might be able to use three lamps and have it work!
But there is the 720mm fl problem.
You just might be able to use three lamps and have it work!
But there is the 720mm fl problem.
About a year ago I came up with an idea for a double light.
A second lamp is added directly behind the first. A lens is then put between them so that the focal image of the second is directly on the point source of the first, and aligned with the lcd / fesnels etc. In theory you could increase the lumens without increasing the size of the point source. You could use two lower watt bulbs with smaller point sources to create a better high lumen point source.
Click to view attachment
One of the gurus here at lumenlab pointed out that the heat would probably split the middle lens. If I ever get my first project finished I might give it a try, or perhaps you could.
The proof is in the pudding.
A second lamp is added directly behind the first. A lens is then put between them so that the focal image of the second is directly on the point source of the first, and aligned with the lcd / fesnels etc. In theory you could increase the lumens without increasing the size of the point source. You could use two lower watt bulbs with smaller point sources to create a better high lumen point source.
Click to view attachment
One of the gurus here at lumenlab pointed out that the heat would probably split the middle lens. If I ever get my first project finished I might give it a try, or perhaps you could.
The proof is in the pudding.
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