Photography : its history, processes, apparatus, and materials ; comprising working details of all the more important methods / by A. Brothers.

  • Brothers, A. (Alfred)
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Photography : its history, processes, apparatus, and materials ; comprising working details of all the more important methods / by A. Brothers. Source: Wellcome Collection.

    37/512 (page 15)
    tlioiight of and tried, but the difficulties to be overcome were great, llerscliel, Le Gray, and others tried albumen and gelatine in which to form the silver compounds on the glass, but with very little success. Collodion had also been suggested, but it remained for Mr. F. Scott-Ai’cher to introduce a process in which collodion on glass took the place of paper, and which in a very few years came into almost universal use. The process is unlike the others already named, inasmuch as it is capable of producing both positives and negatives. The process was not patented, but presented to the world—a free gift, and it is impossible to exaggerate its importance. The details were published in 1851, and the method has remained to the present time unrivalled, as in certain respects the processes which have to a large extent superseded it do not give results equal to collodion. There are disadvantages attending every process as yet introduced, especially when they are to be worked away from home, and attempts were very soon made to displace the wet process by others which dispensed with the silver bath. The most successful rival to collodion for many years was the collodio-albumen process, and there were many others, all having the same end in view, that of getting rid of the silver bath, and at the present time gelatine for all outdoor work has entirely taken the place of collodion. The camera, as now con- structed, is so reduced in weight as to leave very little to be desired, but the weight of the glass still remains, although even that difficulty appears in a fair way to be removed by the introduction of films or sheets of celluloid coated with gelatine enndsion, used from roller slides attached within the camera. A method was introduced by Talbot whereby the silver plate was etched in such a manner that it could be printed from in the copper- plate press. Within the last few years many methods have been invented, and in some cases patented, having for their object the production of blocks or plates which could be used as illustrations for books. The uncertainty of the stability of prints in silver led to the invention of two methods of much importance : first, the Autotype— a process by which pictures are made in carbon, or any other pigment, and as to the permanence of which there can be no doubt. Then, following this, Mr. Walter Woodbury invented the process called by his name. It would, however, be almost impossible to enumerate even the names of all the processes which have been introduced within the last thirty years, not to go farther back. The most important, which may be named here, are Photo-lithography, Collo- type (under various names). Zinc-etching, and Photogravure. The wonderful results already attained naturally make us hesitate