Cold Light - What to expect??

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I've finally broke down and bought a cold light head for my 23c(for B&W work). To date, I've been using a condenser head and Ilford MG IV FB papers and filters. The funny thing is that I've been completely satisfied thus far by using these papers without any filter, although I've been having some problems with dust on negatives showing up on my prints. I've heard people raving about cold light, and I found one for under 100 bucks so I decided to give it a try. My question is: I'm pretty sure I won't be able to use the same papers with the cold light, and was wondering what might give me comparable results. I realize I'll have to experiment to find what's perfect for me, but can anyone give me a good place to start? Once I find a good paper to compliment the cold light source, will I now have to go broke buying several different grades of that paper(The light source is not VC)? Any other hints or Tips in using the cold light? I'd really appreciate any input you all could give, and I'm highly enthusiastic about using my latest darkroom addition.

-- Paul Klingaman (Paul.Klingaman@seagatesoftware.com), May 17, 1999

Answers

Yes there will be a difference, but I dont think you will have to throw out all your Multigrade paper stock. Assuming you have a lamp made by Aristo (they have a web site but Im not sure of the exact address) you can get in touch with them for their recommendations about filters that you leave in place in addition to the multi grade filters that will correct the color for your paper.

-- tony brent (ajbrent@mich.com), May 17, 1999.

After 20 years of not using cold light, I've gone back to it, and I love it. The light colour is quite different to that assumed by the VC filter manufacturers, but they still work fine. I haven't done proper testing, but I guess the #1 filter gives me a grade 2 or 3. Changing filters also changes the paper speed, but that doesn't bother me.

-- Alan Gibson (Alan.Gibson@technologist.com), May 18, 1999.

First a URL for you:

http://www.aristogrid.com/

You should find the answers to your filter questions there. Next, some amplification on what you can expect when you make the switch. Once you get set up and have made a few prints to get used to the new lamp, try re-printing some of the photos you made with the condenser system. Try to match print density as closely as you can to the earlier print. You should see much more, and much smoother high values in the print made from the cold light. You may find that the negatives you made earlier that were tailored for the condenser are a bit on the thin and muddy side when you use the cold light. That's normal. It means you have been compensating your neg development to match the artificial contrast increase that a condenser system gives to the high values (denser negative areas). You will probably find you can expose more fully for shadow detail, and develop more fully for richer highlight detail without having the high values going blank white. In fact, areas that used to print blank white on your earlier prints should show some definite detail when printer with the cold light. Another benefit to using the cold light is that it will match very closely the tonal range you get in your contact prints. If you print your contact sheets to look the way you want them (set up the enlarger for an 8 x 10 print, filter and expose to get good looking contact prints) you should be able to leave everything where it is and go right to making an enlarged print, and it should be a very close match. Play with it. I think you will be pleased.

-- tony brent (ajbrent@mich.com), May 20, 1999.


Hi Yes, variable contrast papers and filters are not calibrated for cold lights but don't toss the variable contrast papers yet. The trouble is that the blue sensitive emulsion in variable contrast papers like Ilford MG IV are the hard contrast and since cold light is heavy in blue, you'll typically get harder contrast on cold light than with tungsten sources. Also, the filters will not give you evenly spaced contrast grades. Your options are to move to the V54 head which is designed for variable contrast papers. Alternatively do some experimenting and you'll find some extra filtration will solve your problems. The trouble I had was in getting lower contrasts on paper so that I could print some of my harder contrast negatives. Typically filter 0 or 1/2 was giving me what looked like a normal grade 2. I find that with some extra green filtration (the soft emulsion is sensitive to green) or extra yellow filtration, I get the gaps filled out. I use 30CC green, 20CC yellow and 40CC yellow Wratten filters to help patch in softer grades that I need. These might serve as beginning points in your experiments. The advantage of cold light is that its energy spectrum is a lot more efficient in terms of printing. Steve Anchell's book on variable contrast papers also is a useful source.

-- N Dhananjay (ndhanu@umich.edu), August 06, 1999.

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