The Wet-Plate Collodion process, introduced in 1851, involves coating an enameled metal (Ferrotype or Tintype) or glass (Ambrotype) plate with a collodion mixture, which is then sensitized, exposed and processed – all within a few minutes and while the plate is still wet. The resulting image (while technically a negative) is made up of extremely fine silver particles that are creamy-white in color, which allows the image to be viewed as a positive when seen against a black background. For example, a wet-plate collodion image made on glass, an Ambrotype, would appear as a negative when viewed on a light table, but if the plate were held over black velvet (or the back of the plate was painted black) it would appear to be a bright and lustrous positive image. So, the same process can be used to produce both glass-plate negatives and one-of –a-kind, direct-positive images on black metal or glass. Either way, wet-plate collodion plates are capable of rendering exceptional detail and extraordinary subtlety in tone. Positive plates have beautiful, milky-metallic quality not unlike a daguerreotype and must be seen firsthand to be truly appreciated.
Overview of process steps:
• Plate is coated with a prepared collodion mixture.
• Coated plate is sensitized in silver nitrate bath.
• Plate is loaded into plate-holder (while still wet) and exposed using a view camera.
• Plate is returned to the darkroom where it is developed, fixed and washed.
• Later, when it has dried, the plate may be varnished to protect against oxidation.
Total elapsed time: Less than 10 minutes from uncoated plate to finished image!
FAQ’S
WHAT IS COLLODION?
Collodion (also called Pyroxylin or Nitrocellulose) is nitrated cellulose fiber, which has been dissolved into a solution of ethyl ether and alcohol. It is a clear, syrupy liquid and once the solvents have evaporated it becomes a clear, flexible, plastic-like film. It serves as the “goo” that holds the photo-sensitive salts in solution and keeps them stuck to the plate, in much the same way as gelatin does in common film and photo paper emulsions.
WHY IS IT CALLED A “WET-PLATE”?
The materials used in this process lose most of their sensitivity to light once they have dried. So, all processing steps must be carried out while the plate is freshly prepared and still wet.
DO I HAVE TO BE NEAR A DARKROOM TO MAKE WET-PLATE IMAGES?
Yes. Your camera can never be more that a few minutes away from the darkroom, otherwise the plate will begin to dry. However, a “darkroom” can be something as simple as a small, lightproof tent or even a box with armholes (like those in a sheet film loading tent). Civil War-era photographers used the wet-plate process to make battlefield photographs under horrifying conditions, while carrying their mobile darkrooms along with them, and still managed to make spectacular images. So stop complaining.
CAN I MAKE PRINTS FROM MY WET-PLATE IMAGES?
Yes and no. If you make an image on a clear glass plate, it can be printed as you would any other negative. However, plates to be used as negatives will need more density and contrast than would be desirable for a plate made for positive viewing. So, even though the processing method is essentially the same, you should decide beforehand whether you want a positive or a negative plate.
CAN I PRINT ONTO COLLODION PLATES USING AN ENLARGER?
Yes. If you want to end up with a positive-image plate, you will need to put a positive transparency in the enlarger. Exposure times are long, but not unmanageable.