Alternative photographic processes
Riccardo Beretta
Concorezzo (MB)
Chemist · Photographer
In a digital world where we take thousands of photos we never look at, I chose to return to slowness. Printing with alternative processes means using your hands, sunlight and chemistry to create something that is not just an image, but a physical, tactile, lasting object.
Alternative photographic processes are printing methods born in the 19th century, obtained through the direct contact between medium- or large-format film negatives and a chemical emulsion. They predate or are contemporary with the better-known silver gelatin process which, with its industrialisation, made them fall into oblivion.
They are called 1:1 prints: the final result is the same size as the negative used to form the image. Unlike today, where everything is uniform and standardised, these techniques leave wide room for personal experimentation, producing truly unique handmade works — cyanotype, palladiotype, platinotype, Van Dyke, salt print.
Having practised my main profession as a chemist for almost twenty years, I have noticed that many use these techniques without full awareness, with “baroque” procedures or without considering the hazards of some substances. All the results you see here are the fruit of real personal experimentation, always grounded in the literature of the field.
Author’s note
My aim is not to give you the “magic” recipe, but to make you understand the reason behind each step — so that you can build your own personal recipe.
No.
Register of techniques · 3 entries
01
Cyanotype — a chemist’s complete guide
The most accessible of the alternative processes, and the first I practised. A photosensitive reaction between two iron salts which, exposed to UV, form the characteristic Prussian blue: a monochrome print on cotton paper or canvas, with a tactile quality impossible on a screen. In the article: reagents, emulsion, exposure and development in water.
Origin
J. Herschel · 1842
Reagents
Ammonium ferric citrate · Potassium ferricyanide
Result
Prussian blue
Level
Accessible
02
Cyanotype and toning — the colour is not final
The colour of cyanotype is not final. Through successive chemical baths — tannic acid, tea, coffee, red wine — the print shifts from olive green to sepia brown, from slate grey to near-black. Each toning is a distinct reaction: the same image, from the same negative, becomes a completely different work.
Origin
Undefined
Reagents
Tannic acid
Result
Tonal toning
Level
Intermediate
03
Selenetype — a variant of the Van Dyke print
A technique of my own, derived from the Van Dyke silver print. The historical problem — the mixed formula is unstable and after a few hours is no longer repeatable — is solved at the root by working with two separate solutions, stable indefinitely, mixed only at the moment of coating. In the article: full formula, development, fixing and the chemical reasons.
Origin
Van Dyke / Namias 19th c.— personal reworked ·
Reagents
Ammonium ferric citrate · Silver nitrate
Result
Warm brown
Level
Intermediate
