The term “calotype” is from the Greek kalos meaning beautiful. It is the name given to Fox Talbot‘s negative process. The name is often mistakenly applied to photographic “salted paper” prints (positives) which have been made from calotype negatives and as such the term calotype often requires disambiguation when conducting photographic research. In short, a calotype is a negative which is created in a camera, and a salted paper print is the positive print which can be reproduced many times over from the original negative.
The advent of this process brought with it a few key changes to Fox Talbot’s process. Firstly, the negative was not printed out using the action of the sun (as was the case for the photogenic drawing) but rather “developed” out using a chemical developer. This change was a symptom of a profound discovery which was that of the “latent image“. It was discovered that a sensitised paper negative could be exposed to a fraction of the light previously required for the photogenic drawing. The short exposure was registered in the paper as an imperceptible photochemical change which was not visible to the naked eye, but which could later be developed out. The advantage to this was that exposure times were dramatically reduced allowing for greater flexibility, more spontaneity (this is relative to the period of course!), and the use of larger photographic plates allowing for larger prints. The negative/positive process was born in earnest and would serve as the backbone of photographic industry until the advent of the digital era.
Few examples of calotype negatives remain in St Andrews, but the legacy of their production lives on in the prints which they were used to create. Much of the most important early photographic material within our collection is represented in original photographic albums from the mid-19th century onward. These unique objects illustrate a rich variety of printing media employed by both amateurs and experts of this early period in the development of Scottish photography.