The dominant photographic process used between 1851 and 1880.
Frederick Scott Archer made what was, arguably, one of the most important contributions to the development of photography in the first twenty years of its existence. Having presented his process free to the world, he died six years later in relative poverty and is today, unfortunately, little remembered or honored for his work and his genius This was the first photographic process that allowed multiple prints of fine detailed images.
I started experimenting with this process along with calotypes and paper negatives back in 1982 after reading a text in a Paris library while doing research on platinum printing. Many of the images here were shot in small apartments I had in Paris and Milan during those early years with my bathroom filling in for a darkroom. Here I have put together a brief basic description on the procedures I now use today.
Wet Plate Collodion Glass Plate Negatives and Positives (Ambrotypes and Tintypes) are produced using basically the same procedures with slight changes to the chemistry and exposure. With the Ambrotype and Tintype (positive images), you can add color with pastels or stains to the finished plate just as they did in the 1850's. They can then be used in the production of the beautiful Archival color chrome pigment prints.
The process begins by cutting the plate, glass or tin, to the size of the final image. These plates are then, if glass, meticulously cleaned with a chemical and allowed to gas off overnight or, if tin, painted with black japan (a black paint mixture) and cooked in an oven. Next, the plate is held at the corner, perfectly flat in front of you and a mixture of collodion (the collodion emulsion mixture of potassium iodide, bromides, ether & alcohol is poured onto the plate. In a single critical motion the plate is tilted slightly to each corner so that the poured puddle flows in one direction to cover the plate and the excess is dripped off the corner. After a few seconds the collodion becomes stiff and attached to the plate. Now, the lights must be turned off as the plate is immersed into a silver nitrate bath which makes it sensitive to light. When sensitizing is complete, the plate is placed into the light tight wooden wet back. Somewhat similar to a standard film holder it attaches to the back of our old wooden turn of the century cameras. The cameras are fitted with brass lenses designed and used by original wet plate photographers in the 1850's. These lenses look like a large brass coffee can with glass on both ends. There is no shutter in the lens and F stops are flat pieces of metal each with a different size hole in them to limit the amount of light going through the lens. No light meter is used. Exposures range from seconds to a few minutes. The experience in using the process trains you to exposure by the "guess method".
The exposure is made by removing the lens cap for the alloted time. This must all be done while the plate is still wet from the silver bath, depending on climate, this usually needs to be under 6 minutes. As soon as the plate is exposed, it must be taken into the darkroom for developing under an amber safelight. Developing is done by holding the plate with the collodion side facing up in one hand and by pouring the developer from a vial onto it with the other hand. Pouring of the developer is the most critical part of the process. It is all in the technique that determines the final look of the image. Masters of the process struggle daily with this most delicate part. It must be fast, but not too fast, the whole plate needs to be covered in a second with the least amount of developer possible. Any defect or variation creates marks on the image making each plate unique. Now you are looking for the image to appear which is somewhat similar to that of a regular photographic print. The image (if exposed properly) starts to show in 7 seconds and is usually complete in 10 - 20 seconds for the ambrotype and up to several minutes for the negative. When development is complete, running water is flowed over the plate to stop it.
The plate is then fixed in your choice of potassium cyanide or sodium thiosulphate. Each has a different effect on the final image coloring. Potassium cyanide killed many photographers of that era due to storing the chemical in glass containers that often broke, they then cut themselves and died when the chemical entered the blood stream. If cyanide was accidentally mixed with the acetic acid, a chemical used in the developer, it produced cyanide gas making the dark room into a death chamber (potassium cyanide is the chemical used in modern day gas chambers). One little slip, your dead and your prints double in value. Fixing the ambrotype and tintype makes them come to life, the visual change in the plate at this point is truly amazing, Like watching a flower bloom in fast forward.
Now the plate is washed in water and air dried. For protection of the delicate collodion image a varnish is poured over the plate. This is done by heating the glass or tin plate over a flame and pouring the varnish over it just as you did the collodion. Each plate is unique, like a snowflake, impossible to reproduce exactly due to the many variables in the process.The negative can now be digitized or printed on silver gelatin paper or put through a bleaching or intensifying process for alternative prints like platinum, salt or others.
The ambrotype needs to have a black backing attached to show all
of it's details, without this the image is almost invisible. Black japan
is applied to a separate piece of glass and cooked over a flame, when
dry it is attached to the original glass plate's back side. This is then
digitized and the original is framed to view as a finished ambrotype.
Like the negative plate, the digitized ambro can now be printed to
any size imaginable.
Making the chrome pigment prints in the studio at the art
quality level exceeds the difficulty and time involved of any
toned silver print and many of the alternative processes of the 1800's, but is well worth the effort. Fortunately now, we are no longer limited to short archival life processes, small image sizes, paper textures, inferior silver print papers of the current day. Inconsistent toner colors and the wasting of hundreds of gallons of water with the chemical contamination being subjected into the environment. No longer does a series of 25 prints show 1 fantastic print (usually the framed print in the gallery show) 5 or so excellent prints and 20 that are only close to what the artist envisioned. The longevity of these pigment prints, after receiving the archival process, by far exceeds all previous color photographic prints and are as good as most alternative prints such as platinum, salt, albumen, carbon and others. The paper is now the weakest archival link as is the case with most alternative print process's.