John Herschel and Cyanotypes

Sir John Frederick William Herschel, was born on the 7th March 1792. Apart from being an astronomer like his father William, who discovered Uranus, he was a mathematician and a chemist – for photography enthusiasts he is most famous as being the discoverer/inventor of the cyanotype process.

The City of Bath has already been mentioned on this blog before, but I return to it for a visit to The William Herschel Museum.

My first attempt to visit was a failure as when I got there it was closed! This time “open” ! Inside can be found a great and interesting selection of exhibits, but for me the most interesting was the workshop. This is located at the rear of the basement, and includes a replica of the machine used to polish the mirrors for telescopes.

Happily my visit coincided with an exhibition of the work of artist Jennie Gilling, she uses the cyanotype process in her work, coating hand made papers, with the light sensitive solution. “Seed Pressure” (below) is from 2013.

Seeing this work was something of an inspiration – so I just had to have a go. Although I had never tried it before I did a bit of research and ordered up the chemicals. In fact there are only two needed which are mixed into a single solution, ferric ammonium citrate and potassium ferricyanide. The solution once mixed, is light sensitive, to UV light – so no sunlight, but one can operate in dull tungsten light, this makes it much easier when coating the paper. As soon as the paper is dried, it can be exposed, in the sunlight. Everything I read suggested that exposure is a guess helped with a bit of experimentation and experience! I also read that it is difficult to overexpose, and this all seemed to be true! I also found that if the solution was left overnight to “brew” – it seemed to coat the paper better and be more even. The image is fixed when the paper is washed with plain water – removing any remaining active chemical.

Below are my results – hope you like them!

I think the last one of Fennel from the garden is the best, the actual print almost has a little 3D effect to it and more detail to the others. I also tried making a large “negative” on the photocopier – this is from a digital image of mine, converted to B/W then negative, and printed onto an acetate sheet. The things people get up to in their garden during lockdown!!!