The Wet Collodion Process

14031075_10153722089821921_679977314_nFrederick Scott Archer was the son of a butcher from Hertford who went to London to take an apprenticeship as a silversmith. Later, he became a sculptor and found calotype photography useful as a way of capturing images of his sculptures. Dissatisfied with the poor definition and contrast of the calotype and the long exposures needed, Scott Archer invented the new process in 1848 and published it in The Chemist in March 1851, enabling photographers to combine the fine detail of the daguerreotype with the ability to print multiple paper copies like the calotype. In publishing his discovery, he did so knowingly without first patenting it, giving it as a gift to the world.


This process originally called the wet-collodion process, or simply the collodion process, and as we call it today the wet-plate collodion process. This process involves adding a soluble iodides & bromides to a solution of collodion (cellulose nitrate) and coating a glass plate with the mixture. The plate is then immersed in a solution of silver nitrate to form silver halides. The plate, still wet, is exposed in the camera. It is then developed by pouring a solution of pyrogallic acid or ferrous sulfate over it and then is fixed with a strong solution of sodium thiosulfate, for which potassium cyanide was later substituted. Immediate developing and fixing were necessary because, after the collodion film had dried, it became waterproof and the reagent solutions could not penetrate it. This process was valued for the level of detail and clarity it allowed. A modification of the process, in which an underexposed negative was backed with black paper or velvet to form what was called an ambrotype, became very popular from the mid- to late 19th century, as did a version of black lacquered metal known as a tintype, or ferrotype.


The Silver Sunbeam list 10 different steps to process a single positive wet collodion photo. Those Steps are described as follows:

  1. Preparation of Glass: A piece of glass is thoroughly cleaned, sized and polished. This step is skipped for tintypes.
  2. Coating with collodion: While holding the plate in a horizontal position the collodion is flowed onto the plate to make a smooth and even coating on it.
  3. Sensitizing it: The coated plate is then placed into a bath of silver nitrate for several minutes to sensitize it.
    1. In darkroom conditions, the plate is removed from the bath and placed into a lightproof box, called a plate holder. the plate holder is carried to the camera, locked into place with the dark slide facing the lens.
  4. Exposing it in the camera:  The dark slide is removed; we are ready to take the photo.  The exposure times vary based on the lens, light, weather and the chemicals, but is generally just a few seconds. This is done by removing the lens cap and replacing it.
    1. The plate holder is closed up, and taken back to the darkroom.
  5. Developing the picture: Back in the darkroom the plate is then removed from the plate holder and developed out by pouring a developer solution over its surface. When the plate is judged to be fully developed, it is stopped from developing any further and rinsed using clean water
  6. Fixing the image: Out of the darkroom the plate is then fixed by placing it into a chemical solution sodium Thiosulfate, generically called Hypo or Fix which dissolves the remaining unexposed silver, and prevents the silver from further darkening. Permanently fixing the image. It is then thoroughly rinsed in clean water.
  7. Drying the plate: The plate is then dried either by air or by use of a small alcohol burner flame.
  8. Coloring: The image is then hand-colored to give life to cheeks, or color to curtains, and so on. (this step is typically omitted) 
  9. Varnishing: The plate is then warmed and varnished to protect the image.
  10. Backing: Then finally for ambrotypes. The plate is coated with asphaltum or provided a backing made from paper, velvet, or an unused tintype.

For the different solutions, we use modern adaptations of historic recipes, we choose not use potassium cyanide as our fixer to avoid the potential risk associated when working with the public. The chemicals used in modern wet-plate photography are considered ORMD and are still considered as toxic if not treated with respect for what they are.

Meet the lenses

With in the last few of years, we’ve had some luck with fortunate opportunities to collect a few different lenses, at present, I have used each of the lenses, each of them offer different unique prospective, as well as some interesting histories. I’m listing them in chronological order of acquisition

Darlot Rapid Hemispherical

darlot lenses.jpg

I suppose, aside from the lens on our Gennert Cycle camera our first historic lens, came on a camera, that I like to call the Franthony (french made camera using Anthony hardware and design) it came with Darlot rapid hemispherical #2 size lens. this lens is composed of two doublets – another name for the lens is Rapid Rectilinear or RR540px-Rapid_rectilinear.svg


It’s interesting that Darlot’s catalog entry states that the #2 covers 10×12 but more often then not people use it a smaller format camera thinking its only good for 4×5 or 5×7 – I typically use it on my 5×8 Rochester Optical, but have used it without any issues on my 8×10


Darlot Rapid Hemispherical #2 with it’s flange mounted on the ROC’s lensboard

Continue reading “Meet the lenses”

Alpha working model 1 test

It seems that, the 8th of inch difference doesn’t effect the edge to edge coverage of the plate, however my 1st test, using using the alpha 4×5 model it did basically work except that my dark slide apparently isn’t as opaque as it visually appears, however for this model that’s ok in that the final materials haven’t been decided on, for the next model, I have to make some adjustments, and will likely use an original dark slid, at least until I can replace it with the correct materials.

as labeled this is an alpha version I’m still resolving some of the details.

4×5 Alpha plate holder

Universal Plate Holder

I spend most of Tuesday the 3rd of August 2016 working out details of the universal plate holder. and cutting out via a laser cutter a working model to to test some different idea’s.
At present time the working model is made of a couple different types of plastics – partly due to the thicknesses of the said plastic as well as availability, I’m presently undecided as to what type of plastic will be used if not a combination. My principle reason for using a plastic is based upon assemble, general durability and resistance against the silver used in wet-plate photography.

wet-plate holder
Modern Wet-plate holder


Sadly, one of the biggest issues I’ve run into is a true edge to edge sized image as
traditional with a wet-plate images taken using a specific wet-plate camera. the majority of plate holders were a fixed sized, with corner tabs to support the plate many of those tabs were made from glass or wood, to change size of the plate the photographer would typically use a insert to down size the plate size.




4x5 dry plate holder
4×5 dry-plate holder with film holder insert

Whereas with the introduction of dry-plate and film the industry stared becoming more standardized, through size of plates, film  and camera while increasing the number of shots that could taken via a dry-plate/film holder, this changed how plates and film where held in place, within the holder, it also increased the ability to carry two plates/film per plate holder and later process the plate/film. During this transition from wet-plate to dry-plate/film a number of photographers still used their big camera’s and simply used inserts or a new concept, adjustable plate holders. the insert or adjustable plate holder was soon dropped in exchange for fixed camera sizes in relation to film size. and as roll film quality started increasing the size and weight of the camera decreased.


Today designing, rather than modifying a film holder for a view camera, I’ve encountered the previously described design change from wet-plate edge to edge image to one with boarder, this change is universal to the camera’s rather than being limited to just the film holder. Thus a fixed size modified film holder may not have a boarder, if the holder has been modified to support a plate that is smaller than the said film holder. but if the plate is at the maximum size of the holder, it will always have a boarder of about 8th of an inch. my plate holder are designed to support the true size of the said plate . However based upon the sizing of the camera they will always have a boarder when the maximum sized plate to plate holder is used. this is an unfortunate side effect, that can be used to one’s  advantage.


For example:

Here’s inside of the back from our 4×5 mid 1920’s Ansco Universal, note the space is not a true edge to edge 4×5 – the standardized film holders with with a spring back were designed to fit a 4×5 sheet of film, but also created a boarder on the film – this boarder offers several advantages and is typically cropped when printing