Posts tagged "Chemistry"

Investigating Cyanotype Developer Absorption

Sunday November 5 2023, 1995 words — Or, why *are* those damn things so slow?!
Filed under: Cyanotype, Photography, Chemistry

If you’ve read my previous article you know that there were some loose ends I was meaning to tie up using good old science, specifically the significant loss in sensitivity observed when mixing the classic potassium ferricyanide “developer” with your ammonium ferric citrate or ferric ammonium oxalate.

So let’s do that!

A quick recap

Before we get into it, a quick recap of how the “classic” cyanotype process and formula works!

We usually start out with two compounds, ammonium ferric citrate and potassium ferricyanide which get dissolved in water and brushed or otherwise coated onto some kind of substrate, usually paper.

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Making better cyanotypes

Friday August 11 2023, updated: Sunday November 5 2023, 4041 words — Bringing 19th century photography into the 21st century. Maybe.
Filed under: Cyanotype, Photography, Chemistry


This blog post is roughly based on a short talk I gave at HFG Karlsruhe early this year and this is my attempt to finally expand on it a little and make the contents publicly available. It’s not really a tutorial on how to actually make cyanotypes, but more of a general overview of different techniques.

I’ve spent the last 8 years working with cyanotype and have developed some stuff that I think could help make other people’s cyanotypes better. Maybe.

I mean, what even is “better”?

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