Newbie to b&w has cold light question : LUSENET : Large format photography : One Thread

Up until now, I've always shot 4x5 transparencies, with acceptable results, simply because I don't have the space for a darkroom to do black and white. I recently started taking an introductory black and white class at a local art school. The class has taught me, among other things, an infinite number of new ways to ruin what would otherwise have been a perfectly good photograph. Despite the setbacks I've suffered at my own hands, I'm hooked. Now I'd like to use a bathroom in my house to set up a small darkroom. (So far I've only been developing and printing 35mm in the class.) I'm thinking of purchasing a used Omega C-700 enlarger for 35mm to keep costs down while I'm still getting my feet wet in black and white.

My question is this: Is it possible, or even desirable, to fit a cold light head in a 35mm enlarger? I've read the pros and cons of condensor vs. cold light heads, and would like the flexibility of installing a cold light head later. Can this be done? Also, what is a jam nut?

Thanks for any insight you advanced b&w folks can provide me.

-- Dan Blair (, July 27, 2000


Dan: I looked at Aristo's web site ( don't see a cold light head for 35mm. They do have one for a 2 1/4 inch neg. I don't know if your enlarger is 2 1/4 or not. I would recommend, IMHO, that you buy a 2 1/4 enlarger instead of 35mm, because of increased flexibility. It is a little bigger, but not much. To answer your other question, a "jam nut" is usually a nut that tightens up against another nut to keep it from loosening. A lot of tripods have a jam nut arrangement to mount a camera. You tighten the screw into the bottom of the camera and then tighten a large flanged nut on the screw to keep everything tight. Jam nuts are used in many applications on automobiles. Many of the photo enlarger heads have jam nuts on the head bolts.

-- Doug Paramore (, July 27, 2000.

If your proposed enlarge has a diffusion color head (most all color enlargers use a diffused light source) the light quality is virtually the same as cold light and I would not hesitate to work with it.

Personally, I would not hesitate to recommend a good condenser head, but there are many varied opinions about this. I've used condensor, color diffusion heads, and cold light. Color heads are the easiest for me, but I've done excellent prints with each.

The jam nut used for enlargers is usually just a large diameter thin nut that screws onto the back of the enlarging lens to hold it onto a lensboard. Some enlargers have a threaded hole so a jam nut is not required. Others have a plain hole, and the nut is needed. The most common size is 39mm "Leica threads". These are cheap ($2 to 10 each) and available at almost any photo store that sells darkroom equipment.

I think the C700 does up to 6x6, so it might not be a bad entry at low cost.

Good luck with your endeavors, Charlie

-- Charlie Strack (, July 27, 2000.

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