Dry Plate Ambrotypes
In the 1870s and 1880s, silver gelatin based photography was still a new and unfamiliar process to the professional wet plate and tintype photographers. To bridge the gap between the positive collodion-based processes and the new silver-gelatin based processes, a hybrid positive process appeared briefly on the scene. Similar to collodion-based ambrotypes, silver gelatin based emulsion is coated onto black glass and developed to a positive.
Resulting from a visit down to New55's facilities, it was noted that developing J Lane Dry Plates in Famous Format No. 1 Monobath resulted in a very lightly-toned off-white silver grain.
This result was combined with a source of smooth black glass to provide the opportunity to shoot ASA 25 speed "dry plate ambrotypes". More recent investigations by Lee Lira and myself into the "design" of a developer provides increased contrast and a tonal range closer to a creamy white color. These investigations are ongoing, but recent results provide for a beautiful one-of-a-kind positive photograph similar
While the intent is not to replicate collodion-based tintypes, the process allows one to produce an ambrotype (a directly-exposed positive image on glass) while metering at significantly faster exposure speeds (ASA 25).
This process is still experimental. FF No.1 Monobath can be ordered from Famous Format's shop and used to develop to a positive (note: it doesn't work because of the use of a monobath .. it's the details of what is mixed into their formula which is important).
Alternatively, I can mix and provide 1 QT working solution of Lee #2 Developer - tuned for this process - for an additional $20. The developer comes in powder form and is mixed and used according to the included instructions.
4x5 and 5x7 plates are 1.5mm thick.
8x10 plates are 1.8mm thick.