B@W printing with a color head on VC B@W paper

[Cosby]

I have an enlarger with a color head and would like to print on variable contrast B@W paper. What filter packs are equivelent to which B@W filter grades?

[John Cook]

Ilford has excellent technical information on their website. Here is the pdf file which deals specifically with your subject: http://www.ilford.com/html/us_english/pdf/Cont.pdf

I believe the downside of this technique is that your print exposure will need to change as you horse around with these enlarger head filters. The beauty of the VC filter sets made specifically for this purpose is that their density is calibrated to eachother.

[Nick_3536]

Depends on which paper you're using. Every [or should I say every one I've seen] VC paper maker provides charts. The two colour ones [yellow and magenta] are I think speed matched. The chart you need must match the paper you're using and the enlarger you're using.

[Tom Perkins]

Yellow and magenta. The cyan has no effect on variable contrast paper except as a neutral density filter. There shouldn't be any real difference between a color head and a dedicated VC head. Don't worry too much about the filter packs; you can use the recommended ratios, which is a good place to start, or you can just add magenta to increase contrast or use yellow to decrease it. If you make incremental changes and watch what happens you will have better results, based on your own experience.

[Paul Butzi]

Various combinations of yellow and magenta will produce various contrasts. cyan filtration will have no effect, because cyan filtration subtracts red light, and the paper is not sensitive to red light.

Adding magenta and/or decreasing yellow increases contrast; subtracting magenta and/or adding yellow reduces contrast. Equal amounts of magenta and yellow form neutral density, and can be used to speed match your settings.

For a more formal approach, see my article at www.butzi.net/articles/vcce.htm

[Jay DeFehr]

Hi Paul. It's good to see you here. I calibrated my Beseler computerized color head according to your article, and my printing has both improved dramatically, and become much more efficient. Thank you very much for the article and instructions. I used my Omega color analyzer as a comparator for the ND calculations, and determined that one step on my Stouffer's stepwedge equals 1.5 steps on my analyzer's density dial. I've been struggling to learn to use my analyzer to determine image contrast and printing time. Do you have any tips along those lines? I would love to see an article as thorough and well thought on this subject as the one you wrote on color head calibration. Thanks again.

[Paul Butzi]

Jay-

My tips would fall along the lines of this: use the analyzer to measure the density of the highlights and shadows of the negative. If you have your head calibrated to hold highlights constant, you can use the highlight density measurement to calculate a starting exposure that would, for instance, land the highlights on the paper as barely textured white. You can then use the density range of the negative (the difference between highlight and lowlight density) to select the paper's exposure scale, adjust the filtration, and then make a first print.

This is essentially what is done by a device like the RH Designs ZoneMaster II, except that the ZM has the ability to give you feedback about where other metered areas will fall on the tonal scale before you make a print.

[Jay DeFehr]

Thanks Paul. That's pretty much what I've been trying to do, and I suppose it's just going to take a while to get comfortable with the equipment. Thanks again for the excellent article and instructions.