Caffenol

Caffenol is the name of a developer liquid for black and white films on the basis of caffeic acid. In Caffenol is a so-called alternative developers because its ingredients are available at any drugstore or supermarket. Caffeic acid addition of instant coffee contains Caffenol washing soda ( sodium carbonate), which acts as a pH regulator solution. Caffenol emerged as a result of research at the Rochester Institute of Technology (RIT ) in the mid 90s. The first message that you can develop films with coffee, but dates back to 1937 and was an April Fool's joke ( The photo exhibition, April 1937, page 14).

Variants

Caffenol C: To speed up the development process and to increase the image contrast can Caffenol with vitamin C (ascorbic acid) are added. The development times correspond to those of conventional chemicals.

Use

The developer solution is used undiluted directly after preparation. The exact development times are einzutesten for the footage used in each case. Caffenol developed relatively slowly ( at least 30 minutes for black and white films ) and provides very soft, balanced negatives. In Caffenol C reduces the development time to 10-12 minutes at a steeper gradation and sometimes very coarse grain.

Current status

Today ( 2013) is widely used Caffenol -C, as the combination with vitamin C provides significant advantages. There are now metric recipe in grams / liter, which allow a far more reliable manufacture than with the traditional method teaspoon. In addition to instant coffee, vitamin C powder and bicarbonate of soda and iodized salt or potassium bromide ( from the regular photochemistry ) used as an anti -fogging agent to achieve very good results even with highly sensitive films.