Forgotten in its old age

by Aditya

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

I read recently an article on Wired Magazine about a guy who did an installation using "carbon prints". Searching around on the web I came across this page, where it is stated that:

These ‘photographs’ are made from negatives which utilize a carbon emulsion on a transparent base – the result of my experiments and manipulation. Numerous generations in the fluid’s history create minute evaporation trails, rendering an archeology of time.

This sounds like pseudo technical mumbo-jumbo to me. Is this a real alternative photographic process, but with some carbon compound?

share|improve this question
    
These were the best tags i could think of. Feel free to retag for better exposure (pun intended) in people's filters :) –  JoséNunoFerreira Sep 7 '12 at 16:58

1 Answer 1

up vote 8 down vote accepted

It's a process similar to that used to photographically create screen prints (serigraphs).

A UV-photosensitive water-soluble emulsion (typically gelatin sensitized with potassium dichromate) containing a pigment (in this case, carbon or lamp black) is used to coat a surface. The emulsion hardens under exposure to strong UV, becoming more-or-less insoluble in proportion to the amount of UV exposure. The emulsion is exposed to a UV source through a negative image, meaning that the parts that are supposed to be white in the print are dark/opaque in the negative, and the areas that are supposed to be black in the print are clear/transparent, allowing the UV to strike the emulsion and harden it.

After the exposure, the print is washed (carefully) in warm water (usually around 40 degrees Celsius, or 100 degrees Farenheit) dissolving the unhardened gelatin and taking the excess carbon pigment with it.

Carefully working with negatives exposed using strong single-colour filtration and multiple thin emulsions containing different colours of pigments, it is possible to create full-colour pictures using this technique. That often includes a lot of hand-masking of the negatives so that colours can be layered in different orders in different parts of the picture. For complex prints like that, one usually starts with a full-colour traditional photographic image, and the colour-separated negatives are made from the full-colour positive image. (Although as a specialty hand-crafted printing technique, it has largely been replaced by dye transfer printing, since the transparency of dyes means that there are far fewer exposures and emulsions required, and following a simple yellow-magenta-cyan-black order will produce the desired colours.)

It's often difficult to tell what artsy types are yammering on about when they wax rapsodic about their techniques. It is quite possible that the artist used many different negatives, emulsions, exposures and washings in his process, but I'd take the "evaporation trails" part with a grain (or, rather, a large block) of salt. Unless you use a high-enough drying temperature to cause bubble damage to the water-expanded gelatine, evaporation does nothing for the image except to make it a whole lot less damp.

share|improve this answer
    
I see. So the carbon is just the pigment that tints the remaining exposed emulsion. Thanks! –  JoséNunoFerreira Sep 10 '12 at 0:38

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.