Chapter 14: Cyanonegative Photography

What we call cyanonegative photography uses paper sensitized with cyanotype as the detector in a homemade camera. A simple lens is used to focus the image; after a long exposure, the blue-tone paper negative that results is scanned to produce a digital positive. Suitable choices of paper and cyanotype sensitizer formulas are described. The wavelength response of cyanotype is reviewed in light of how a typical outdoor scene is imaged by this method. A technique is described for making a positive contact cyanotype print directly from a cyanotype negative.