Monday, June 30, 2014

Blogging for the Moon: Lunar Caustic

Unfixed Salt Print on Fotokemika Varycon
I'm sorry spiders, I've just been feeling down for a while. A few things happened that kept the sad rolling and I just wasn't able to muster the mental fortitude to resist. So I spent a while trapped in the fog, with no work to break me out. I did manage to do some experiments while I was in there, but I just couldn't get to the record keeping and documentation steps, or actually bring myself to write them up. I've let you down, spiders, and I've let down Thor, Freya, Baron Samedi and the Sun itself. Darn.

Well, as I've been forced to hear repeatedly in recent days, all you can do once you've made a mistake is learn from it and move on, trying your best not to repeat the mistake. I know that I'll be late to blog again, but I'm really trying to get better. I might even try to write my blogs early and schedule them to automatically post on Thursdays. That'd be pretty novel!

Let's skip that stuff and get to what you actually care about, right? Spiders care nothing for human trials, but love some photography. Or something. Today's topic is one of my recent experiments: salted lumen prints. I was lead to this idea by John Fobes, who coated one of his lumen prints in albumen mixed with ammonium chloride. Mr. Fobes got some very interesting color shifts as a result of printing on the still-wet albumen-coated paper, but it got me wondering if it would be possible to use silver gelatin paper as a base for salt prints to combine the salt print with a lumen print.

I soaked two sheets of Fotokemika Varycon fiber-base paper in a simple solution of filtered tap water and kosher salt, the same kind of solution I'd use to soak normal paper before making a salt print. I used quite a lot of salt, getting the water up to the saturation point. Then, I allowed both sheets to dry completely overnight before coating one sheet in the same 15% silver nitrate solution used for salt prints. I allowed that sheet to dry for several hours as well, then exposed them both as I would normal lumens, for 1 hour each.

Overall, I did not see a big difference between a salt-soaked lumen print and a regular lumen print, at least not on the Fotokemika Varycon paper. They look about the same, the only significant difference being that the salted print had less color and was overall less vibrant. I'll be testing other brands of paper to see if I can achieve different results. I think Mr. Fobes' use of albumen also contributed to the color shifts he saw, not just the application of chloride.

Using the silver gelatin paper as a base for a salt print proved effective. The paper doesn't take coating as evenly as something more porous would, but I think that can be solved with multiple coats of silver nitrate, or just more careful application. The image looks very similar to a traditional salt print, but carries strong undertones of the paper color. The unfixed image carries much more of these tones, but that's because fixing destroys most of the color in Varycon paper. I plan to experiment with a more vibrantly colored paper, maybe Collodio POP or Harman Direct Positive, but the concept proved itself. You can make a salt print on silver gelatin paper, and doing so does affect the final image.

Friday, June 20, 2014

Blogging for Freya: Horrible Plagues

Ugh. Every time I deal with kids, I get some new disease. I was on my way to blog last night when I was struck down with some kind of bone-aching stomach fever. It's better now, but it was pretty nasty. On the bright side, my summer camps seem to be going well this year, and I even have a workshop for adults to throw in there on the side. So things are looking fairly decent as far as my activity and productivity levels go!

I had been planning to write a very short and simple guide to salt printing at home, but the plague wiped me out. I'll try to write it this weekend. Sorry, spiders!

Friday, June 13, 2014

Blogging for Freya: Stumped

I know it seems weird, considering how often I miss my Thursday deadline and end up posting on Friday, but I do have a backlog of ideas for posts. Right now it's 5 of them, and I've really been wanting to dive into one, but it turns out to get more complex each time I start on it. It has to do with categorization in photography. What's the difference between a chlorophyl print and an anthotype? Is this a chemigram or a lumen print? Are my un-developed cyanotypes lumen prints? If I dunk a lumen print in developer, is it still a lumen print?

This may be developing into a serious taxonomically induced existential crisis. I don't know how to categorize a lot of the work I'm doing now. It bugs me sometimes, mostly when I get told that I'm labeling my processes wrong. If I make a "lumen print" with liquids instead of solids, now it's a "chemigram" for some reason. The whys and whens of what to call different photographic techniques are messy.

Sometimes, I'd really like art to borrow a bit more from science and actually define things. Scientists know what they mean when they say something is organic or inorganic, metallic or non-metallic, a semiconductor or a superconductor. I want some taxonomic certainty!

Friday, June 6, 2014

Blogging for Freya: Basic Chemistry

4 hours, regular water
2 hours, basic water
2 hours, acidic water
Ugh, sorry Thor! I'll make it up by posting twice this week. I just lost track of blogging today.

I have previously experimented with exposing lumens in water. Often a paper has totally different characteristics when exposed to moisture, so lumens made in water will tend to display a radically different color scheme than normal. Since both the paper and the printing object are floating in water, contact is limited and the images are blurry, sometimes very blurry if the paper or object are disturbed in the water. Debris can get into the water, moving around and creating interesting background results. The water adds another dimension to the printing process.

Over the last few days, I decided to try something else. I already knew from
other experiments (and just basic darkroom chemistry) that photographic paper reacts not only to moisture, but also to acids and bases. Developer, for example, is basic. Stop bath is acidic. I once tried painting liquid detergent (a strong base) onto photopaper, only have to it turn black within seconds. I knew ahead of time that by adding acids or bases to the paper, I could influence how it developed. So, I mixed up some solutions and exposed lumen prints in either a slightly acidic solution, or a slightly basic solution.

My base solution was just a simple addition of baking soda to hot water. I dissolved the soda completely, though I do plan to do some later tests with larger amounts to see what it does when large amounts are in direct contact with the paper. From these preliminary tests, I found that (as expected) the baking soda solution seems to accelerate the exposure. Normally the paper tested, Fomalux RC Contact Paper, shifts from violet to green over the course of 4-5 hours if exposed underwater. When immersed in the baking soda solution, that time was cut in half. I got a full conversion to the desired orange-green scheme in just under 2 hours. Normally a 2 hour exposure in water is just brown. I'm going to experiment with this to speed up other long-exposure papers like Collodio POP and Harman Direct Positive.

For the acid solution, I used anhydrous citric acid crystals, which I did not fully dissolve. In one test, I sprinkled the crystals directly onto the paper. No significant results, but the areas of contact did show some minor resistance to exposure. In general, the acidic environment did as expected and slowed exposure considerably. The Fomalux paper, after 2 hours, was a dull brown with very little contrast. It seems to affect the background more strongly than the object (possibly not as much acid reaching the paper where it was covered by the object?) because the object was turning orange already while the rest of the paper was still brown.

I'll be trying with some other solutions and concentrations, but I think this technique (especially the basic solution) has some interesting potential. Speeding or slowing chemical exposure of lumens could allow for some fun play with papers that normally expose too fast or too slow. I need to see if I can produce the results without submerging the prints, possibly by pre-soaking the paper. That would allow more traditional, full-contact lumens. That'd be nice; I like detail.