CYANO - Cyanotype Photos

Cyanotype is the oldest surviving photographic process, and the reason old engineering drawings are called blueprints. Paper is brushed with iron salts, a negative is laid on top, and it is left in the sun. What develops is Prussian blue, in water, with no darkroom and no chemistry set. CYANO does the chemistry in software. This is not a blue filter. A cyanotype is blind to red and green and sees only ultraviolet and deep blue, so it renders the world at the wrong brightness. That is the whole point of it. A bright yellow sign goes almost black. Green leaves go dark. A blue sky burns straight through to bare paper, taking the clouds with it. Two colours your camera recorded as equally bright come out at opposite ends of the print. Everything here is simulated from the physics rather than approximated with a preset. The sensitiser's response is integrated against sunlight across the…