Anthotypes

An anthotype is an image created with photosensitive materials from plants, vegetables, and fruit. It was invented by Sir John Herschel in 1842, but the photo sensitive properties of plant matter have been known long before then and are mentioned in the observations of Henri August Vogel in 1816. The plants, vegetables, or fruit are crushed and often combined with alcohol to form a tincture which then coats a sheet of paper. After the paper dries, it is exposed to direct sunlight to bleach out the image. Henry Hunt Snelling said that the juices of many plants "produce very good photographic effect." (The History and Practice of the Art of Photography. New York: G.P. Putnam) 

http://www.alternativephotography.com/wp/processes/anthotypes/anthotype-process

http://lenscratch.blogspot.com/2009/11/carol-golemboski.html

http://www.make-a-print.com/section431011_150891.html

My group decided to test tonal range with 5 fruits and vegetables and three variations of exposure time. We used:

• spinach - it contains iron which has produced decent images in other photographic processes, 
• beets - they have a strong color and are concentrated
• tomato paste - it is highly concentrated, easy to extract, has no seeds, and other forms of tomatoes have too much water 
• raspberries - they have strong color and are concentrated 
• dried cherries - they are a different consistency than the others fruits and vegetables and were suggested by Peter

We combined each fruit and vegetable with about ¼ cup of alcohol in a food processor and put the blend into a strainer or coffee filter to get a tincture.

Two coats of each vegetable and fruit extract were then put on 5 pieces of paper, each cut into 4 pieces; after the paper dried, we each took a fruit or vegetable paper home.

Step wedges made of neutral density filters were taped to 3 of the pieces, which will be exposed for 1 week, 2 weeks, and 1 month. The fourth piece will be used when we determine the exposure time that results in the best tonal range, and we will each try to make an anthotype with an object or positive image.

The blending of the food and alcohol was easy but we had to use different approaches when trying to get the extract. The raspberries were the thickest and went right through the strainer so we needed to use a coffee filter. More alcohol needed to be added to the tomato paste because it was too thick, and we had to use two coffee filters to prevent them from tearing while getting the extract

Both Snelling and Levi L. Hill mention juices changing color between when they are first applied to the paper and after the exposure is done so it will be interesting to see if any of the vegetable and fruit colors we used will change.

Anthotypes made with positives:

http://www.flickr.com/photos/hansbazar/800291191/

http://www.flickr.com/photos/photo_de_nuit/5040165299/

http://www.flickr.com/photos/antonyp/2080519842/

http://www.flickr.com/photos/antonyp/2079732803/