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Monday, July 26, 2021

CONTINUITY: Do-It-Yourself Cyanotype Photography

The cyanotype process was invented by astronomer John Herschel in 1842. The chemistry is sensitive only to ultraviolet light, so no darkroom is required. Exposure is usually by sunlight, which contains enough ultraviolet to (very slowly) form an image. This is the process used to make blueprints, and was used for that purpose well into the 20th century.

Posted at July 26, 2021 14:47