Tuesday, April 12, 2011

Van Dyke Brown

part A:
Ferric Ammonium Citrate: 9.0 gm
Distilled Water: 33.0 ml

part B:
Tartaric Acid: 1.5 gm
Distilled Water: 33.0 ml

part C:
Silver Nitrate: 3.8 gm
Distilled Water: 33.0 ml

Parts A and B are  mixed together and then C is added slowly while being stirred. This solution, kept in a light tight bottle such as an amber bottle or a white platic container will keep, like cyannotype, for up to a year.

The Van Dyke solution can be applied in the same manners as the cyannotype, different brushes will create different effects, we can also make a mask to keep very clean, controlled edges if that is the look we're going for. We use x drops of solution per A5 piece of paper and y amount of drops for A4...

Van Dykes are a "faster" process than cyanotype. Faster refers to the speed in which the light sensitive material reacts to light. The exposures for cyanotype were anywhere from 15- 40 min long and we could coat our paper in incandescent light. With van dykes we need to keep them in very low, safe light to prevent the material from "fogging" - reacting to light and getting darker. Our exposure times for Van Dyke were much faster, ranging from 3-9 min.

It is another printing out process in UV light (sunlight). Printing out means, while we are making the exposure we can see the image begin to appear. Once we've seen our image appear the darks will look like a burnt sienna colour (dark orange/brown) and our image will be about half as dark as we want it to be in the final image.

Take the exposed print to the darkroom, and "develop" the print in water for 3-5 min. This should clear away the left over unexposed chemicals. The next bath is 4tbs of sodium thiosulfate (hypo)crystals per liter of water.  This is the fixing bath which will darken and fix the image. The print should remain in the fixer for 5 min. The final stage is a last bath of contantly refreshing water to wash the prints clear of all chemicals. This wash should last for 30 min. The final print will "dry down"- darken once it has dried.

i had everyone coat extra sheets of paper so you can take them home and make exposures during the week. I'd like everyone to bring in at least 2 cyanotypes and 2 vandykes they made for next week that they are very pleased with. Please try to make an exposure in your pinhole cameras!

Class is going to start at 12pm next week, as we have a lot to do and need to catch people up.

I want everyone to come in with their negatives anywhere from 120- to A4 in size. I would like everyone to have their paper already torn down to size and have their names written on each piece so we don't have to waste time getting that done. Consider printing on other types of paper, fabrics or other surfaces. Catalina made some collages from different images she found in a magazine which looked really interesting. For those of you who are printing negatives think about contrast, you will want to make very contrasty negatives to print... please take a look here for more technical information on making negatives. Picnick is a great free online photo editor- if you want to add effects or edit your images. It is very comprehensive. You only need to upload your images. http://www.picnik.com/

if you can't come to class, please let me know as soon as possible so i don't hold up the class waiting for you to show up.

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