Friday, January 30, 2009

From Digital to Cyanotype

Alternative processes for photography are most often UV light sensitive only. Because UV enlargers do not exist, you need a negative the same size as the final print for contact printing. In the past this has mostly been done with either in camera original negatives (using large format view cameras to produce the negative) or enlarged negatives using copy film. Tillman Crane, an accomplished photographer and platinum printer, has an extensive description on how to produce an enlarged negative in a traditional darkroom.

The resurgence of interest in alternative photographic printing in relative terms just preceded the emergence of widespread digital photography. William Crawford's The Keepers of Light published in 1980 was a guidepost for many early re-practitioners of  these processes.

Photography exists primarily for the masses and for commercial use to communicate, influence and store memories. Insofar as widespread commercial use overlaps the needs of the artist, materials are available for the artist's use. As digital photography began replacing traditional photography across a broad spectrum of the photographic business (event and sport photography, photojournalism, consumer) sources of materials for traditional film-based photography - including material for making enlarged negatives for contact printing - began disappearing.

I think it is this ability to blend the old alternative processes with new digital methods for making negatives that will rapidly emerge as the standard approach to making traditional photographic prints. 

At the top of this article is a (transmission) scan of the digital negative I created to produce the cyanotype print below. Using Mark Nelson's Precision Digital Negative system. I calibrated the traditional cyanotype process using step tablets to determine an ink combination to produce a negative on Mitsubishi Ultra Premium Pictorico film on an Epson 3800 with full tonal range and densities calibrated to the process, chemistry, paper and light source. Digital negatives are created on transparent film using dye or pigment based inks. It is obvious that the negative is not black and white as is a silver negative. Exploiting the different UV blocking capabilities of the different colors of ink in a printer is key to producing high quality digital negatives.

The second image above shows the coated sheet of Arches Platine paper with the cyanotype emulsion before exposure. The digital negative is sandwiched ("emulsion" to emulsion) and placed in my built-in vacuum frame in my custom UV exposure unit from Edwards Engineered Products.

My exposure time is 3 minutes and 32 seconds, which is quite a short exposure for cyanotypes. As the image just above shows, cyanotype is a printing out process, which means the image is fully created during exposure. Traditional silver gelatin printing is a developing out process which shows no image whatsoever until the exposed print is subjected to chemical action by the developer. Some processes like palladium printing are partial printing out process where the developer completes the visible changes started during exposure. For the exposed cyanotype, the paper is cleared of unexposed emulsion by placing it inverted in a tray of water, ensuring there are no trapped air bubbles under the paper, and letting it stand for 8 - 10 minutes. The goal is to remove all of the yellow emulsion stain from the image. Depending on your paper, your wash time may be longer. Following clearing, a 30 second dip in a tray of water to which a splash of hydrogen peroxide solution has been added will bring the image to full intensity immediately. The step is unnecessary if one has patience as the image color will strengthen to the same end result in 24 hours or more. I let the print drip free holding it by a corner, and then lay it flat on a paper towel. I take a roll of blue shop paper towels and roll it over the print to remove any surface water remaining and then allow the print to dry. Alternately you can simply hang dry the print. The print may be flattened in a press for final mounting and presentation.

I have a lot more to cover about digital negatives and alternative processes!

Monday, January 26, 2009


I've been struggling with technical aspects of cyanotype over the past couple weeks. And those struggles go to the root of why I started this discourse. To describe challenges and solutions and approaches for some processes I'm experimenting with.

The problems I have encountered so far include highlight staining, unblocking shadow detail, resolving mottling in mid-tones and highlights and achieving a smooth tonal gradation. I've been discussing these problems over e-mail with Mark Nelson, Sam Wang, Chris Anderson and Beth Moon, and re-reading Mike Ware's and other's technical notes on coating methods and problems. These problems and their solutions will be discussed further in the next few posts.

I have been using three test images during my calibration of Herschel's classic cyanotype, and those images suggest an approach to test image choice when tackling a new process.

The above high key image challenges the process to distinguish tone and detail in highlight. It also brought to light the mottling of the emulsion when coating Arches Platine that my low key image hid.

Much of my work when tackling a new alternative process involves calibration with a step tablet, determination of exposure time, and construction of curves using Mark Nelson's Precision Digital Negative system. At some point towards the end of that calibration process you want to print a test image that exhibits a range of tones from shadow to highlight with mid-tones present. Also, the image should have detail to allow judging the sharpness of the image. I have been using the image of the figure in coiled irrigation duct for that step.

For checking the calibration and handling of shadow detail I use the low key image to the left. The interior of the black bowl has a lot of subtle detailed variation in the darkest tones of the scale and revealing those details in a print requires a careful calibration and adjustment curve for each alternative process.

Paper choice, emulsion formula, coating method, development, humidity. These all factor into the calibration of an alternative process. Variations in any of these will affect the final result and ultimately mean the difference between a mediocre print, a good print and the final goal of an exquisite one.

Sunday, January 25, 2009

Cool Resource Site for Epson 3800 Printer

Mark Nelson sent out a note pointing us at a resource site for the Epson 3800 printer.

The Internet is so cool.

The page is maintained by Eric Chan - who seems like quite an interesting fellow.

Some Technical Notes from David Michael Kennedy

David Michael Kennedy is an accomplished photographer and palladium printer. His landscape work is moody and immediate. I love his portrait work - and the way he expresses them in his prints. Rangefinder Magazine has an interesting profile on him.

But, once again, I digress.

He has published some extensive technical notes on palladium printing technique on his website that I stumbled across while looking for information on how much Tween 20 (a non-ionic detergent - by the way) to use to help an emulsion, in my case cyanotype, absorb into the fibers of the paper.

Realize, dear reader, that many of these alternative processes are related - or at least have related challenges. Scout around in other processes when looking for solutions to a problem you may run into.

Wednesday, January 21, 2009

Light Sensitivity of Alternative Processes

So, I've been preparing some scans of the various steps of making an image in cyanotype. I'm not the most accomplished print scanner (just setup my Epson V750 scanner which I had bought some time back to scan some 8" x 10" black and white negatives I have). I use a discontinued Imacon (now Hasselblad) 646 film scanner for my 4" x 5" film work which is similar to the current Flextight X1 model.

But I digress.

I scanned a dried but not exposed sheet of Arches Platine to illustrate the color to expect of a good emulsion and as I retrieved the paper to print my digital negative to show the next step I noticed it had partially printed out where it was exposed to the scanner fluorescent light.

Did I mention the cyanotype process is a printing out process?

The cyanotype process is slow as these things go, exposure that is. Depending on the strength of your UV light source exposures can range to 15 minutes or more. I was somewhat surprised that the sheet partially printed out from the scanner light, but shouldn't have been.

For the UV sensitive alternative processes you don't work in a darkroom as much as a dim room. I use a low wattage incandescent bulb, definitely not one of the newer energy efficient fluorescent replacements! If I coat multiple sheets of paper, I will put them in a black portfolio box to keep away from all light. If I'm simply drying a couple sheets for some quick work I leave out and I don't stick around to watch - but do turn off the incandescent light while I go watch another episode of Tales of Tomorrow.

For reproducible results, and preservation of one's sanity, controlling variables such as ambient illumination, humidity, and temperature can eliminate transient problems in your work.

That said, I am quite vexed by a mottling of the lighter mid-tones of my test cyanotype image. Another test awaits.

Sunday, January 18, 2009

Bulk chemicals vs. pre-packs

At some point one will ask themselves the question "Should I buy pre-packaged chemicals or buy them in bulk?" This is almost the same as deciding whether to do your shopping at the corner grocery store or at Costco.

The difference in price is great when you consider the chemistry needed for cyanotype.

I buy a lot of my supplies fro Bostick and Sullivan. They sell a pre-packaged cyanotype kit for $24.95. The kit comes dry, pre-measured in bottles. They state that the kit will allow you to make about 200 8" x 10" prints (about $0.12 per print). The kit is shipped dry, you simply add distilled water to the top of each bottle and shake and you're done.

What is very convenient and safe about this is that you never handle the dry chemical, there is no measuring and transfer, and little opportunity for the fine powder to go airborne. All that said, wear gloves and a mask when preparing and handling the kit. Once the solutions are made, the emulsion is mixed as needed in small amounts for coating paper by combining the two solutions in a 1:1 ratio. The shelf life of the solutions is two years.

What is cool about Bostick and Sullivan is they have instructions on line for several alternative processes, including cyanotype.

You can buy the chemicals for the cyanotype process in bulk from a place like Art Craft Chemicals. There are many formulas for mixing the sensitizer and the Prussian Blue precursor (ferric ammonium citrate and potassium ferricyanide). I am mixing 
  • Solution A: 20 grams of ferric ammonium citrate (green) into 100 milliliters of distilled water (the sensitizer)
  • Solution B: 8 grams of potassium ferricyanide into 100 milliliters of distilled water
I bought 1 pound of ferric ammonium citrate for $30.00, and 1 pound of potassium ferricyanide for $16.50. Normalizing the quantities (I need less potassium ferricyanide than I ordered) this is sufficient to make almost 10 times the amount of solution at only twice the cost of the Bostick and Sullivan kit, or very roughly 2 cents a sheet of 8" x 10" paper. And you can coat 2,500 sheets.

And herein lies the basic problem. How sure are you that you will like the process to do that much printing? Is blue your favorite color? The other problem is: to create the stock solutions you will need to purchase a small scale for weighing and some measuring cups (you're not going to use the measuring cups you use for cooking, just as you are not going to prepare the solutions anywhere near food). As you transfer the bulk chemicals and divide into smaller portions you have a much greater likelihood of airborne dust - more a hazard than the mixed solutions themselves.

A final problem is that these - and other chemicals for alternative processes - are hazardous materials. If you tire of a process you will have more chemicals to dispose of properly if you buy in bulk than if you buy the smaller kits. Christopher James's book has a good discussion on handling many of the chemicals for alternative processes.

Some things to consider as you explore different processes.

A final thought. It is well known that the sensitizing Solution A for cyanotypes is a perfect breeding ground for mold - I've been skimming it off in fascination. It does not seemingly harm the sensitizer (but can ruin a coating if you don't remove it from the solution). I never saw this with the Bostick and Sullivan kit - I think Kevin Sullivan is adding a preservative to Solution A to eliminate this problem.

I'm not a fan of mold.

Thursday, January 15, 2009

Brigitte Carnochan

Copyright Brigitte CarnochanI went to Brigitte Carnochan's opening of Imagining Then at Gallery 291 in San Francisco tonight. The work struck me very hard and left me in an emotional state that I can't shake.

Gitta's hand-painted photographs of figures and still lives are exquisite. This new work is very different. Working from photographs and objects from her parents, Gitta constructed a view and interpretation of her memories, her parents, and a time. She found the time to focus on the project after putting it aside for a few years as she recovered from shoulder surgery. By that time she had acquired expertise in digital image making that allowed her to realize her vision.

The images are collages of pictures, documents and letters mostly from the 1940's. Images of Gitta and her parents are juxtaposed with scenes from World War II Germany, and then Gitta's journey to the United States. Gitta as a young girl against the backdrop of a massive, painful conflict that left its impression on her life.

The show itself is well presented, and it starts on a strong portrait of a bold child, and then leads the viewer emotionally through a devastating time with images seemingly rising from a young child's attempt to understand the change and pain around them. The final image of is one of hope and closure.

Gitta's show runs from January 8 - February 28, 2009.

It's morning now. And the images still haunt me. Isn't that what good art is about?

Tuesday, January 13, 2009

The Epson 3800 Printer

I use the Epson 3800 printer to produce my digital negatives. There, I've said it.

So, one thing I continually bump into is there's not enough time in the day to do all the things I want to do with my photography. And I try to ask people who are working in similar areas for recommendations on equipment and technique.

I have Epson 4800 and 9800 printers, and they are fine printers indeed. I do many a digital color or black and white print with them and have been very pleased with the results. The problem I ran into with these two printers occurred when I started trying to produce digital negatives for palladium printing with high key images. A negative for a mostly white image consists of large swathes of solid ink lay down on Mitsubishi Ultra Premium Pictorico film. While studying the prints I noticed that there were uniform horizontal varying bands of light and dark (oddly the size of the print head seemingly) forming an undulating wave that was visible in the final print. I mentioned this to Mark Nelson and he replied he had seen this before and called the problem venetian blinds (putting a name to my pain). Not on all printers, and only in large, low contrast light areas of the resulting print (corresponding to areas of highest ink density in the negative). Interestingly Alain Briot mentioned that he had seen this density variation artifact in the shadow areas of some straight digital prints, but that the effect seemed transient.

This is not the same as a clogged head resulting in no ink from one nozzle and microbands appearing across the print. That requires a cleaning cycle. These are 1 - 1.5" bands varying dark to light and back again running parallel to print head travel. The effect is very subtle (but noticeable - someone else noticed it first in a print) similar to paper warped by moisture and wavy and showing shadows - except the paper is flat.

Mark mentioned in a moment of my deep despair that he had never seen this on an Epson 2200 (which I had just given to my friend Ken) - or an Epson 3800.

An Epson 3800 is a fine printer for generating digital negatives. I mentioned that already, I think. With a 17" wide carriage it can produce 16" x 20" negatives for large contact prints. One limitation of the Epson 3800 compared to the Epson 4800 is that there is no roll media support. I have to cut down the Ultra Pictorico roll material to size to feed into the printer. On the other hand, the Epson 3800 has a much smaller footprint that the Epson 4800 and can be considered a desktop printer (the Epson 4800 strains that definition). It is reasonably priced.

I use the Epson 3800 for straight digital prints also. It holds both Matte Black and Photo (Glossy) Black ink cartridges and will automatically switch between inks depending on whether you are printing glossy or matte surface paper. Ultra Pictorico is glossy. Some ink is wasted during flushing of the shared ink line so you don't want to switch inks say between each print but rather group your printing sessions if you go back and forth between media surface types.

The printer is a work horse and I'm very pleased with it. 

Another feature of the Epson 3800 is that it outputs 16 bit files rather than 8 bit files - with the right operating system and driver. While it is missing on a list of pro-imaging printers that support 16 bit operation, it is on another list and I can confirm that the MacOS X 10.5 driver has the option for 16 bit printing. Mark Nelson hopes that the support for 16 bit images will result in even smoother tonal transitions in digital negatives.

Someday maybe I'll figure out what the issue is with the 4800 and 9800 printers. I've already varied platen height, ink density, print quality (dpi), suction, orientation of the media (when cut into sheets), and colors used for the negative. For now I don't use these two printers for making digital negatives.

I have not tried to produce digital negatives on other printers besides Epson. I suspect that is in my future.

Sunday, January 4, 2009

Feeling a Bit Blue

Bleu, bleu, le monde est bleu.

I spent the past couple days wrestling with classic cyanotype. This is somewhat embarrassing, given the supposed ease with which this most basic of processes can be done. Invented by John Herschel (a famous polymath) in 1842, it is simplicity itself. Two chemicals, expose in sun, develop in water, dry. Voilà! Anna Atkins created the first photography book consisting of sublime photograms of British Algae using this process.

Above is the cyanotype paper after a 6 minute UV exposure and before water development. Note the dark tone reversal (Prussian White, which reverses back to Prussian Blue on oxidation in air).

I've had two problems. Well, maybe there's a third one.

First, I've had runoff of the emulsion in the water wash. At various times as I've approached this process I've made small steps of progress. The cyanotype process does not like alkaline environments. Papers, contamination, or water. I purchased an Extech PH100 meter to determine that my tap water was alkaline (8.5 pH). So I now acidify my water a bit. I tried several papers as I've mentioned before. Crane's Platinotype and Crane's Weston Diploma had a lot of emulsion runoff for me. Bergger COT-320 (my preferred palladium printing paper) did not work well either. It has been somewhat frustrating in that I spend a bit of time with it and then go off to work on something else and return after a period of months to consider it again.

Obviously I'm not really worrying about this.

Mark Nelson told me that Sam Wang clears his cyanotypes by simply inverting the paper in a tray of water and letting it quietly sit. I was washing the paper, and fiddling with it as I had done for palladium prints. Sam's method is simple and helps reduce the runoff. In trading e-mails with him in the past couple days he said he clears his prints for "5 to 10 minutes" in reaction to my 30 minute clearing stake in the ground ("Life's too short to wait half an hour!", to which I agree).

The biggest reduction in runoff I've gotten is from switching to Arches Platine, per Mark Nelson's suggestion of Christina Z. Anderson's preferred paper for cyanotype (I think?). I am able to smoothly rod coat it, making sufficient passes to get an even coat without puddling of emulsion on the surface. Crane's papers buckled quickly before absorbing the cyanotype emulsion when I tried rod coating before - and then would abrade on hake brush coating making the surface rough. I air dry the Arches paper and then bring it to bone dry with a hair dryer before exposure.

The struggle this weekend on runoff has to do with exposure time. I was told early on during one of my attempts that underexposure will result in emulsion runoff. And I seemed to verify this weekend that a 20 minute exposure had little or no runoff. However, I ended up with an overexposed print (as measured by a Stouffer 31 step wedge designed by Mark Nelson and available on his web site). This irks me - I prefer not to overexpose prints handspring in compensation around it. When I dropped exposure time to eliminate the blocking of shadows in the step wedge, runoff occurred. My goal is at this point to keep it to a minimum.

The second problem I've been having is bleeding of the Prussian Blue into the highlights. This was truly problematic with Crane's Platinotype. A white highlight was not in my ability to pull of with that paper. The technique of fast oxidation by dipping the cleared print briefly in a water bath with a small amount of hydrogen peroxide made the bleeding much worse. Two changes seem to have solved this problem. First, Arches Platine is the cyanotype wonder paper in my book. It is bleed resistant. The second factor was some recent experiments by Chris Anderson. Her web page illustrates the bleeding issue well. The short of it is reducing the proportion of  the ferric ammonium citrate in the emulsion eliminated bleeding. My emulsion is now 1 part water, 1 part Solution A (20 gm ferric ammonium citrate/100 ml distilled water), 2 parts Solution B (8 gm potassium ferricyanide/100 ml distilled water), and one drop of Tween 20 10% solution per 60 drops of emulsion. The Tween 20 help to spread the emulsion uniformly and I added after seeing some beading of the emulsion on the paper during coating. A little goes a long way.

So, much progress was made this weekend. To the right is the developed print after a 7 minute inverted clearing in a mildly acidified water bath, followed by a 30 second inverted immersion in a water bath to which a splash of hydrogen peroxide was added. The bleeding problem is non-existent - I lay the paper flat on a blue shop paper towel and press another sheet on top to remove the excess water before allowing to air dry.

I'm now struggling with blocking in shadows. Looking for some insights from Mark at this point. 

My third problem is one perhaps of perfectionism. Yes, cyanotype is an easy process. But I'm thinking like any printing process (especially alternative processes) it is easy to get a print. To get an excellent print, and to be able to reproduce that feat for other images. Ah, there's the rub.

Tomorrow is another day, I'll take my wins to bed.

The Cyanotype Process

I stumbled across a printout of a chapter on cyanotypes from Christopher James's most excellent book, and I had quite forgotten where I had found it. It turns out the cyanotype process is the sample chapter from his book published  on his website.

This is quite a find, it is full of valuable information on the process, alternate techniques, and toning approaches.

I had forgotten the quote from the naturalist photographer Peter Henry Emerson that is related in James's chapter, "... no one but a vandal would print a landscape in red, or in cyanotype."

Arches Platine

One of the extreme pleasures of alternative processes is playing with some very fine papers. Compared to a purely digital darkroom, alternative processes afford a very sensual experience.

For the past couple days I have been coating (and coating and coating) Arches Platine with cyanotype emulsion. Mark Nelson had said that Christina Z. Anderson (I think) used Arches Platine successfully with cyanotype. This in response to my frustrations with emulsion runoff in the washout with first Crane's Platinotype (which seems to be no longer manufactured, replaced by their cover stock?), then Bergger COT 320 (my preferred paper for palladium prints), and later Crane's Weston Diploma (which also appears to be missing in action now?). I'm making much better progress with classic cyanotype on Arches Platine - runoff is minimal and there is no bleeding into highlights.

The Arches paper mill has a long history. The Fabriano mill has an even longer and storied history

Platine is luxurious. Have you ever stayed in a high end hotel, hit the bed after a long day of travelling, and felt enveloped by a soft but firm bed, and pillows that invited dreaming? I always wondered where they got those beds. Arches is a thick, 100% cotton paper (310 gsm) that comes in 22" x 30" sheets, with a smooth hot pressed surface, and a neutral pH. It is also available in 30" x 44" sheets. It has no whiteners or brighteners, yet appears very white. The front of the paper (watermark right reading) is smoother than the back and is the side I coat. You can tell the smooth front side of the paper from the rougher back side by light touch (with clean hands) - try flipping a paper over and over and see if you can tell the difference. Not as pronounced as Bergger COT-320, which I orient correctly for coating by touch without thinking anymore. I have been easily rod coating Arches Platine, and the well-sized surface is rugged and does not raise a nap or roughen  after repeated passes. 

I tear the paper along the edge of a plate glass top I work on, moving my hands down as I tear about 6 inch sections. This gives the resulting sheet a more natural edge better matching the original edges of the full sheet of paper. I've started wearing nitrile gloves while handling the paper to keep from marring the paper with fingerprints which can interfere with coating.

Saturday, January 3, 2009

The Bromoil Reading Room

A very brief note. I saw a reference, I think in Volume 7 of The World Journal of Post-Factory Photography, to a Bromoil Reading Room. I've been scanning the web with various searches to find on-line versions of out-of-print texts on alternative processes. The bromoilists are very organized in getting material on-line.

Another place to find some photography is on, which has listings from texts scanned from American and Canadian libraries, besides others.

Happy reading!