I’ve spent the past day doing calibration tests on negatives using the Van Dyke brown process. Van Dyke brown is an old photographic process. Like cyanotype, it was first used in the mid 19th century. The process for making a Van Dyke brown print is very similar to the process for making a cyanotype. It’s a little more fussy, however, and unlike cyanotypes, Van Dyke brown prints need to be treated in a fixer bath like regular black and white photographic prints. Van Dyke brown emulsion is much more sensitive to ultraviolet light than cyanotype emulsion is. I’m making Van Dyke brown prints with a four minute exposure, as opposed to twelve minutes for cyanotypes. The resulting prints are a rich brown color, and show a much fuller tonal scale than the naturally high contrast cyanotypes do.
Running exposure calibration tests for Van Dyke brown prints was much easier and faster than it was with cyanotypes (my frustrating struggle with exposure calibration for cyanotype prints is detailed here).
The longer tonal scale present in Van Dyke brown prints meant less adjustment of the transfer curves in Photoshop was needed, and because I had run at least a dozen tests using cyanotype, I had a lot of experience at comparing tones and correctly adjusting the curve. I was able to get really good results in just two steps.
Here’s the first print, made with no adjustments to the transfer curve. It looks pretty good, and I could already see that no major adjustments were needed. The mid to dark tones need a little more separation, that’s about it. I adjusted the transfer curve, printed another negative, and ran another print.
Here’s the result. I think it’s as good as I’ll get. I could be really picky and try to expand the tones in the 90-100% range, but I doubt there would be a noticeable difference in the prints.
While I was working in the basement, I decided to try toning cyanotype prints. There are several different formulas for toning cyanotypes, many of them can be found in The Book of Alternative Photographic Processes by Christopher James. I chose one that tones the prints to what is described in the book as an eggplant black color. It basically involves dipping a finished cyanotype into a solution of sodium carbonate, which bleaches the image. After a rinse, the print is submerged in a tray of tannic acid for several minutes.
I chose one of my old test cyanotype prints to experiment with toning. Here’s the original cyanotype:
and here’s how it looks after being toned.
I like the look of the toned print quite a bit. I’m going to try toning a few more to see how I like them. I’m also going to start printing negatives to use in making Van Dyke brown prints. I’ve got at least four negatives ready to go, so watch this space for more images appearing soon.