Help! Page 2

B&W Sepia Via Color Paper?
Q. I have heard of and am trying to achieve a sepia-toned look by printing black and white negs onto color paper. Is this possible and, if so, what is the darkroom technique? I think I read that you need a certain filtration to achieve this look. What would this be?
Fred Fehr
via Internet


A.
I bounced your question off our darkroom expert, Darryl Nicholas. Both he and I have never heard of filtration being used with a black and white negative to make a sepia print on color paper. If any readers know of, or have tried this, and drop me a line, I'll let you know. Nicholas added this comment: "`The intended purpose of liquid sepia toning of black and white paper prints is to extend the archival life of the image by converting or `replacing' some of the silver salts to a more stable metal... Liquid replacement toners chemically replace the silver salts in the print emulsion into a different metallic compound, typically a compound that is more resistant to pollutants than the original silver. This usually alters the print's color as well. Replacement toners include those that increase the archival permanence of a print. Selenium toning is said to yield a bluish-purplish hue on warmtone papers and reddish-purplish hue on coldtone papers. Sepia toners give papers a brownish color (although one would see considerable variation based on the exact sepia toner used). Gold is often used as the most pleasing way to get a blue-black color. Other colors are presumably possible with experimentation with papers and developers and formulas. Toning often also serves to alter print characteristics (e.g., toning in selenium or gold will often boost density and contrast in the shadows, the bleach process of some sepia toners can result in a slight loss of highlight detail, etc.). These are the toners used for archival preservation (but evidence suggests that toning must be carried to completion for archival protection of the silver image)." Since color prints tend to fade with lengthy exposure to daylight on wall display, it would seem for a longer-lived sepia print you should try liquid toners on black and white papers.

Dichroic Head Variable Contrast
Q. Can you give me the dial in dichroic enlarger code for various contrasts when printing in black and white?
Laurie
via Internet


A.
You don't indicate what enlarger or paper you are using. Here's the advice I obtained from our darkroom expert Darryl Nicholas. Hope this provides what you seek. If not, you might want to contact the manufacturer as he suggests below. Nicholas said, "The specific dichroic filters to be used vary depending on the brand of black and white variable contrast paper being used and the brand of dichroic enlarger being used (the exact processing chemistry, time, and temperature will also have an impact). Here are some numbers that I used to use for Kodak Polycontrast III RC Paper and Omega Chromega color head:
Grade 0 = 24Y
Grade 1 = 22M
Grade 2 = 40M
Grade 3 = 70M
Grade 4 = 110M
Grade 5 = 160M
Here is the same information for a Beseler Dichroic color head:
Grade 0 = 75Y
Grade 1 = 25Y
Grade 2 = 20M
Grade 3 = 40M
Grade 4 = 75M
Grade 5 = 180M
As you can see, there are great variations. Usually the manufacturer of the specific enlarger is the best place to go for this kind of information. They should know how the filters that they use in their enlarger will perform."

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