Photography's Blue Period Gets Its First Major Show in the US
In 1842, British scientist Sir John Herschel experimented with the effect of light on iron compounds, inventing a process to produce the blue-tinted prints we know as cyanotypes.
23 Rare Cyanotype Photos Document Everyday Life of Sweden Before 1900
Cyanotype is a photographic printing process that produces a cyan-blue print. The English scientist and astronomer Sir John Herschel discovered the procedure in 1842, and engineers used the process well into the 20th century as a simple and low-cost process to produce copies of drawings, referred to as blueprints. The process uses two chemicals: ammonium iron(III) citrate and potassium ferricyanide. These vintage photos are cyanotypes that were taken by Carl Curman (1833–1913), a physician…