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| Lacock Abbey. Peter Renn 2013 |
I've been interested in the Collodion process for a long time. I've designed my 'Behemoth' 20"x24" camera to take glass plates or tintype sheets, and I've a couple of cameras in my collection specifically bought or adapted with it in mind. As a way of making very large negatives it's not the easiest, but it does offer a lot of advantages, not least being a unique, very beautiful image quality. The positive images have a subtle, silvery beauty which is especially seductive.
While many processes can be learned from books, almost everything I've read on collodion says it's very hard to teach yourself this way. A lot of what's involved requires hand skills and dexterity; things which can be picked up with expert coaching, and troubleshooting problems, which again can only really be tackled with an accomplished practitioner at your side. The tutor for this workshop was Betsy Reed of the Vacant Chair photo studio, and experienced practitioner who works mainly in the US. She is currently at Lacock as Artist In Residence.
http://thevacantchairstudio.wix.com/homepage#!
We were also joined by Richard Cynan Jones, a photographer who specialises in 19th century processes. Richard brought a fine selection of his own kit along and was especially generous and helpful assisting Betsy and teaching the small group of five of us on the course.
http://richardcynan.wix.com/collodion
Roger Watson is Curator of the Fox Talbot Museum and an expert in early photography. He gave us an introduction on the history of the collodion process and showed us a lovely selection of original 19th century images. He was on hand all weekend giving us the benefit of his knowledge and the historical context of what we were doing.
THE PROCESS
I'll write a more detailed account for the Alternative Processes Manual later but here's a brief overview:
Glass plates are first coated with collodion, a sticky, varnish-like substance. The plates are then sensitised in silver nitrate solution for about three minutes. The coated plates need to be exposed and developed before the collodion dries, which in hot weather can be as little as ten minutes. Under red safelighting, the plate develops in a matter of seconds with little more than a splash of ferrous sulphate-based developer, and one rinsed is no longer light-sensitive. Fixing removes the unexposed silver halides and the image turns from negative to positive before your eyes - a magical process!
The processed plate, once dried is varnished to protect the image silver from tarnishing. Placed in front of a black backing, the image is seen as a silvery-grey positive. This is an Ambrotype.
Blackened metal can be used instead of glass to make a Tintype. The traditional metal is to 'Japan' steel by coating it with a black asphalt-based solution but many practitioners use anodised aluminium sheet as an easier alternative.
The Ambrotype will print as a conventional negative if contact printed or placed in an enlarger, though it's rather 'thin' to be ideal. Altering the development however will produce a negative with much more depth for printing.
PREPARING PLATES
The chemistry is pretty expensive so it makes sense to start small. We practiced with quarter plate (3.25" x 4.25") and half plate (4.25" x 6.5") sheets of glass. The glass is very thoroughly cleaned and edged with albumen (egg white) solution before collodion is poured onto the plate, which is tilted this way and that to make sure it's evenly covered before the excess is returned to the bottle. Easy, right? - No! It took a lot of practice to judge the right amount to use and to have the confidence to pour and tip the plate to get an even coverage. The collodion starts to set immediately and it's all too easy to get ridges, dribbles or uncoated spots. Practice, practice, practice...
As soon as the collodion is poured the clock starts ticking as everything must be done before it dries out. Three minutes in a lightproof bath of silver nitrate solution sensitises the plate, which is ready for the holder once the drips have been wiped from the back and edges.
EXPOSURE
The plate holder is like a large format 'darkslide' (indeed you can adapt these for plate glass work). It goes straight into the camera (previously set up) and the exposure is made. It's slow by modern standards but exposure times in open shade were typically 4 seconds at f/4. The camera is a modern reproduction of an old design, but the lens is a genuine nineteenth century one. The emulsion is not sensitive to the red/yellow end of the spectrum but it is affected considerably by invisible ultraviolet light.
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| Betsy Reed and Richard Cynan Jones set up a test shot |
The exposed plate is quickly returned to the darkroom before it dries. The Fox Talbot Museum's darkroom is a delight: Set in a mediaeval barn it's beautiful, well equipped and air conditioned! We also used Richard's wonderful portable darkroom tent: This uses several layers of red calico fabric to make a working area naturally lit with red (safe)light. The plate is developed with a mere splash of chemical and the image pops up in a few seconds. Fixing can be done in plain Hypo (sodium thiosulphate) solution but Betsy favours a Potassium Cyanide fixer to give a brighter image with a warmer tone. Potassium Cyanide is MUCH more dangerous to use however!
We started with portraits. The vast majority of 19th century tintypes and ambrotypes were made of people. This is mine, made at the back of the barn and showing one of my fellow workshop students: Evelyna:
The marks around the edges are from imperfect coating of the plate, the faint parallel lines are ripples in the collodion and the greenish area on the right is a chemical mark, possibly caused by incomplete fixing (though overfixing can bleach the image rapidly so you take it out of the fixer as soon as it looks right!)
However, so long as the marks don't obscure important parts of the image most users feel they add to the effect.
The chemistry is simple enough in terms of formulae but the process is susceptible to so many variables it seems more like alchemy at times! On Saturday afternoon the silver nitrate bath started playing up, finally diagnosed and corrected by Betsy and Richard who worked well into the evening to solve it. All was well the following morning, ready for us to take the camera further afield.
A PORTABLE DARKROOM
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| what is bright orange and has eight legs? |
Richard was kind enough to bring his portable dark-tent along so we could work 'in the field' on Sunday. This splendid construction is a kind of tented table, covered with several layers of orange/red calico. This allows just enough reddish light in to be able to see without fogging the plates.Set up in the shade of the ancient yew at Lacock Abbey, we had an ideal 'base camp' to work from. If you look closely you can see two pairs of legs sticking out below the red cloth. There is just room for two people. The inside looks like this:The chemical bottles are in pockets on the left. The black thing with the drip marks in the centre is the silver nitrate tank. The empty plate holder is on the right in front of the white square sink. There is a water bag above for rinsing the prints which feeds via a rubber tube. It's very hot in there but it works well.
I managed a better collodion coating this time and made the image at the top of this article. It was satisfying to make a photograph like this at Lacock, which is such an important place in the history of photography. The oriel window directly below the chimney is the one in Fox Talbot's famous image.- the world's oldest surviving paper negative:
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| Fox Talbot; Lattice window at Lacock. 1835 |
The weekend was a hugely enjoyable experience. I loved being on the receiving end of tuition for a change, I learned a great deal and came away inspired to make more images. My heartfelt thanks to Betsy, Richard and Roger for their patience, their skill and their enthusiasm.
I will display a selection of images made on this workshop in the G30 finishing room soon. I will also be conducting more experiments and hopefully doing a demonstration before too long.
Peter.
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| Class of 2013 |
