Searching for Mr. Dmax

Just a quick update on yesterday’s article regarding my attempts to find the Dmax (maximum ‘black’ or dark) for my cyanotype paper with my new acidified water development process. Looking at my 13 minute exposure (Gray card reading 14-2/3), I had thought I had reached the Dmax for the paper/processing combo, except when the print dried down, the darkest area did not appear as dark as my earlier test exposure strip. Soooo I thought I would push my comfort zone and make a 17 minute exposure just to see what happens. Wow, an even better Dmax than the 13 minute solar exposure and no solarization of the dark areas (indication of over-exposure for cyanotype papers). Looking at my earlier exposure test strip comparing the base film side to the non-film side, it appears that even 17 minutes is probably not sufficient to reach my Dmax for this paper and development process.

So when the sun’s solar conditions are right again (a bit overcast this morning) and my gray card reading is at 14-1/2 or higher, I will do another exposure test and this time extend the exposure for an even longer duration; perhaps out to 25 minutes in one minute exposure increments.

Reminds me of my zone system experiments I completed way back when trying to find out the right combination for processing Tri-X film with HC110 (dilution B) in conjunction with printing Oriental Seagull papers in the darkroom. fun, fun, fun. I have a feeling that this experimental process leans into my geeky scientific mode; I guess I will always be an engineer/scientist. sigh.

Nevertheless, this experimental process will eventually lead me to be able to really utilize the full cyanotype color range when I start printing my images. In conjunction with the spot meter reading of the solar conditions, make this cyanotype printing process and subsequent results (pre-visualization) a bit more predictable. Great way to start the new year!

Seasons Greetings & make every day an Earth Day!



 The Flow of Light Brushes the Shadow, an artist book from Singular Images Press, Fall 2022 release, $60.00 (CA sales tax for those residing in the USA) plus shipping expenses. Message me or singularimagespress@gmail for shipping details and PayPal invoice.

Note: The Artist Special Edition (book + extra print) is Sold Out while the regular edition is still available.

Book workshop:

Southeast Center for Photography (SEC4P): Creative PhotoBook workshop, (Sold Out) a virtual event on Zoom; February 25, 26 & March 4 & 5th 2023; from 10am – 1 pm, EST (3 hour session each day, with a week between the weekend sessions to work your book-dummy). 

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