Has anyone tried creating a dual bulb setup?

It would take 2 fresnels cut to size in place of the first fresnel. Then the LCD and second fresnel would be the same.
Here is a quick sketch i drew up. I drew this up as a side view of the pj, but thinking about it, it would be better to slip the screen in half left to right. So lets say this is the view of the pj.
Obviously the gap between the 2 fresnels would need to be very minimal so no seam can be noticed.

Im still in the planning aka dreaming stage of my pj.
Part of me is tempted to just slap something together with a 15" or 8" lcd and my dukane 4003 OHP, but part of me wants to get a nice 17" panel that can do HD. I think having 2 bulbs would really help with the dim corners.


http://www.specialty-lights.com/250040.html

Dual bulb ballast 400W each. 800 watts of projector goodness.

Anyone got any ideas about if this would work, or would the seam be annoying/visible?
Obviously cooling would become an issue with the extra bulb. tempered glass would be needed

Click to view attachment

I was thinking of doing the same thing, but couldn't think of a good way to make it work. First we'd need smaller fresnels with shorter focal lengths. This would mean not one, but two bulbs closer to the fresnel and lcd. But I think the biggest concern would be the joint between the two fresnels.

400W is a lot of heat, 800W would be difficult to deal with first as far as cooling and second the noise of the increased fans.

We could still use 220mm fl fresnels for the collecters, just cut strips off the top and bottoms leaving the middle of the fresnel.
The second fresnel would still be 330mm.

The joint of the 2 is my big concern.

that would make a zero improvement since only half of each fresnel would be capturing light.

Wouldn't you be better off to use a prism, and have both light beams land on top of eachother? I was thinking of doing it that way, but I honestly don't want a huge powersucking monster, 800W, thats a lot.

knew I was over looking something.... seemed to easy...
I don't think it would be a zero gain, but pretty close to it. Because the distance from the corners of each fresnel to its bulb would be shorter, some light loss in the corners would be fixed but not much....

Maybe some precondenser lenses.... Hmmm now its getting pricy with the extra fresnel, 2 precondenser lenses... more for the ballast... and i would need precondensers to only shrink the output in one direction... cus i would still need full width in the other direction.....

Ehhh, thats what i get for reading lumenlab at work. should be working. not getting temped with these ideas.

Hey you can't steal my idea! Just kidding. I ordered two small fresnels three weeks ago to try just that but their in china.
Staples has a pair of PVC page magnifiers that would work just fine for testing if you turn then longways. The trick would to place them on two pieces of plexi. then angle them just slightly to overlap the dark line you know will be there.
If the Staples fresnels are the same as 3dlenes they will have a fl of 330mm I was going to buy the one's from staples but they were $14 and the ones from 3dlenes were $1.95 each.
good luck Dave

Why not divide the system into four quadrants instead of two and use four lower wattage bulbs and four reflectors--one in each of the four quadrants (top right, top left, bottom right, bottom left). Wouldn't it be easier to illuminate rectangles closer in shape to squares by using four bulbs while also assisting with corner light loss issues?

I'm new at this, so I don't see why you would need a precondenser for each bulb--couldn't a four bulb projector possibly eliminate the rear fresnel(s)?

(I know I'm describing an expensive to build and operate projector that would also generate lots of HEAT...) It just makes more sense to me geometrically to use four bulbs to illuminate the LCD.

-coma

If two fresnels could work then so could more the problem is each part adds to the cost.
Going to two lihgts most people would only have to buy one more light