Tagged: collodian process

Ambrotype (early 1850s – 1880s)

ambrotypeAn ambrotype (also known as a collodian positive) was an image produced by a type of photographic process first used in the 1850s, succeeding the more expensive daguerreotype, with the image on glass (as opposed to film, paper or metal).

The resulting image is actually a negative, but when viewed against a dark backing (such as black velvet, or a layer of black varnish) or on dark reddish-coloured glass, appears as a positive. The collodian emulsion is usually protected by a layer of varnish and a glass cover (or sometimes put in the case emulsion-side down), and usually supplied in a presentation case, like the earlier daguerreotype. Ambrotype images were sometimes hand-tinted.

The term ‘ambrotype’ is a particular variant of the collodian positive process (patented by James Ambrose Cutting of Boston in 1854) where Canada balsam is used to seal the collodian plate to the cover glass, but the term is now used to describe all collodian positive photographs.

The ambrotype was popular only from around 1855-1865, and after that the process disappeared from high-street studios. It continued to be used by open-air photographers until the 1880s as the process took a short amount of time. It was superseded by the sturdier tintype process, and also by albumen prints on paper.

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Tintype (1850s – 1930s)

Tintype (front)The tintype (also known as a ferrotype) was a type of photographic process invented in the 1850s that involved using a thin sheet of iron (not tin as the name suggests) as the backing for the image (as opposed  to film, paper, or glass).

Tintypes became popular in the 1860s and 1870s, but were used into the 21st century despite growing competition from prints on paper, and are currently enjoying a revival in interest. Tintypes could be taken outdoors provided the equipment needed to prepare and develop them was at hand. The process was often used at carnivals and fairs for taking inexpensive novelty photographs in a short amount of time, and a photographer could prepare, expose, develop and varnish a tintype plate in a few minutes. The resulting photograph was sturdy and did not require mounting.

Tintype photographs succeeded the ambrotype, which had some similarities. Ambrotypes also used the wet collodion process, but on a piece of glass that was dark in colour or painted with a black backing. The iron used in tintypes was also coloured black, and the resulting image was actually a negative that appeared positive.

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