Re: DIY light source for 10X10" enlarger.

This has been a terrific thread of brainstorming. I've learned a lot and 
also got pointers to things to explore further.

In return for the good input (and in the original spirit of Usenet) I will

look into the LED array simply to get a realistic idea of what it would
cost 
for enough light, what the proper power supply would cost, and try to get 
the actual color temp of so-called white LEDs and post back. It will take
a 
while.

Ventilation for the heat is a good point. I've seen flexible tubes that go

to a high volume, low speed blower mounted far from the object. The idea
of 
using the sky is really "out of the box" :) and actually goes back to the 
old pre-electric, wet plate era where they did contacts only.  (When I get

all pissy about Film-is-Dead posts, I dream of exactly such a setup. No 
juice photography.)

Oh - still on Ventilation -- very cool idea about putting lamps inside 
separate housings outside the head and pointing them into the mixing area.

Given that this beast is about 1500 pounds and 12' tall already, it sure 
doesn't add any significant bulk.(Thinking I could have converted an 
Airstream trailer to a camera with as much bulk.)

Finally, I must test the electric shutter on B for a few minutes. It was
not 
used that way in its original camera, but I have a fused box on the bench 
and welding gloves. :)

Tonight I will try to find time to do tentative drawings of a couple 
housings - one for traditional incandescents, and one for the external 
lights idea.

Thank you all very much again,

John