Getting serious with collodion

Following the workshops at Lacock last summer and Double Negative this spring I have been waiting for the UCA holidays to get the time to start making collodion images in my own darkroom.  While it's possible to work in a portable tent darkroom or even out of the back of a car (as Richard Cernan Jones and Sally Mann have shown) you need to be very organised and have your technique well sorted. It's definitely better to have as much space as possible when you start 'solo'..

I've been assembling the various bits of equipment for this for a long time. Much of it is the kind of stuff used in other alt. processes; the main differences being the use of glass. 2mm picture frame glass is favoured as it's in plentiful supply, though original period plates are often a little thinner.  Plate holders and racks have to be sourced or made and glass cut and cleaned.  (NB: I will write a collodion guide sometime in the future, where I'll list everything needed and how the process is done in detail. There are plenty of guides available already but by writing my own I will help my own understanding).  The silver nitrate bath requires quite a bit of maintenance: Filtering, 'sunning' and testing for pH and specific gravity and dedicated glass beakers, filter funels and bottles are needed. Another investment is a small fridge. I've never had this luxury before, keeping film etc, in the ordinary kitchen fridge, but collodion gives off fumes which would taint the food.  I'd NEVER store any photo chemistry alongside food. It's just not a good idea. - especially when a tabletop fridge sells for less than the price of a box of B&W paper.

First plates:

I used my Thornton Pickard quarter plate for initial tests. This camera is a single lens reflex design with a wonderful lens. (I'm holding it in my self portrait from the John Brewer workshop). It has the advantages of being quick to set up, compose and focus, plus the wooden plate holders are already designed to take glass plates. Being quarter plate (3.25" x 4.25") the plates are small and therefore cheap: Not much collodion per image!  The disadvantages are that small plates are more difficult to pour and the plate holder proved difficult to load with gloved hands. I've since modified it.  I set up a nice simple image and worked on it.

One of my first tests.  Quarter plate. ambrotype (collodion positive on glass)

Film speed is widely described as impossible to define. It varies with the age of the collodion, the recipe used, the developer and the UV content of the light.  Conventional light metering is therefore not much use. The method is to guess an exposure, then adjust based on the result of that. I was lucky to get an image first time, and with a couple of mild tweaks I got a good exposure.

Gremlins strike!
Before I had time to feel pleased with my initial success the problems started.  Moving the camera to attempt a tribute to Fox Talbot's ladder and haystack image I set up a picture of the ladder against the hedge. The result, while striking isn't what I had in mind!  I want to be able to make really clean, blemish free images and then introduce these artifacts at will.

Stairway to Heaven?  A catalogue of collodion defects.

The difficulty I had was suffering multiple problems at once. I had dirt or other chemical contamination on the plate causing "oysters" - marks on the edges, I had problems getting the developer to coat the plate evenly and I had flecks of dried collodion in the freshly poured surface. Couple these with difficulties with exposure (my instinct was to give too much exposure and develop for too long: I've spent so long with traditional film it's hard to deliberately "under"expose.!)

This also highlights the problems of working alone. With an expert by your side, the problems are correctly identified and a solution suggested. It's easy to do what you're told and imagine you're learning more than you are. On your own you have to work methodically and make lots of notes. - I should know this: I tell students to do it all the time!  Eventually I managed a couple of good, clean plates including this one of "Buttercup" my vintage Sunbeam bicycle:

Sunbeam bicycle. a quarter plate Ambrotype

A week or two later Anna joined me for a couple of days and we worked through all the same problems: Frustrating when I though I'd solved them. The big difficulty we had was getting the developer to flow nicely over the plate. Eventually after many experiments we discovered that by adding a little more (20% or so) alcohol to the developer (we were using John Brewer's excellent pre-mixed dev solution) it flowed much more evenly. We also diluted the dev quite a bit which gave more control (in hot weather the image 'comes up' almost too fast to control). The last modification was to adjust the safelighting. It's vital to be able to see what's happening...

One of the cleaner images we managed. Anna's vintage plate camera has a great lens, (uncoated of course) which gives this soft effect when photographing into the light. This is a whole plate Ambrotype.

My second guest this summer was Greg Jones. Another UCA friend and colleague, Greg has lectured on the history of photography and was keen to witness the process. Of course it couldn't just be a demonstration: I got him pouring plates and sitting for a portrait. He also made one of me:

Ambrotype half plates

The picture above shows how Ambrotypes work. The image is a very thin negative on the glass plate, which when viewed against a dark backing becomes a positive. Most of us have experienced this effect with conventional film negatives.  Ambrotype images will print, albeit with some difficulty. Skill is needed to bring out the tones in what is effectively an under-exposed neg. (scanning is much easier but the temptation to manipulate the curve is hard to resist. Note that few published Ambrotypes look as good as the scans posted online!) The emulsion is extremely fine-grained so detail is generally restricted to the quality of the lens. The two portraits above were taken with a Petzval lens taken from an old magic lantern. They are wonderfully sharp at the point of focus and have a curved field of focus unlike the flat plane of modern lenses. Used wide open (magic lantern lenses seldom have aperture controls) the exposures were 1 second at f/3.5.

Greg Jones 2014.  note the diagonal lines caused by the collodion forming ridges as the excess was drained from the plate.