Wednesday, 12 December 2012


These are some of the results from a workshop I attended last month at Sesc in São Paulo about this great historic process called Cyanotype. For this particular work, we've used sheets of orthochromatic film inside homemade pinhole cameras. Ortho films are extremely high contrast making them a great choice for this process. 

The negatives were exposed to an average of 12 to 15 seconds as we had a bright but sunless day, they're later processed normally. We used filter paper to do these prints and they're brushed with a mix of equal solutions of potassium ferricyanide and  ferric ammonium citrate previously blended with water. In fact, one of the greatest advantages of this process is that  you can use any absorbent material that can be coated with the solution, like a piece of cloth or wood.

The results below were printed by putting together the negative and the filter paper like a "sandwich" on a glass support and exposing for 30 minutes in a artificial UV light box. The  prints are immersed in a sink with running water straight after to get the unexposed solution washed away and then let dry normally.

The workshop was ministered by Ricardo Hantzschel from the great Cidade Invertida project.

Below is the negative used to print the image above, note how contrasty the ortho film is.