The Photographic Process

The following discussion of the photographic process is limited to those factors important in photographing spectra and in using the result for interpretation of spectral data. 

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Volume 4 Growth and Properties of Metal Clusters. Applications to Catalysis and the Photographic Process. Proceedings of the 32nd International Meeting of the Society de Chimie Physique, Villeurbanne, September 24-28,1979 edited by J. Bourdon... 

Growth and Properties of Metal Clusters Applications to Catalysis and the Photographic Process", Proc. 32nd Int. 

It has been found that only a few photons, maybe as little as six, are needed to form the latent image. Photographic film is a very sensitive light detector. The final step in the photographic process, fixing, removes the unreacted silver bromide crystals from the emulsion, thus stabilizing the image (Fig. 2.4). 

Despite the fact that not all details of the photographic process are completely understood, the overall mechanism for the production of the latent image is well known. Silver chloride, AgBr, crystallizes with the sodium chloride structure. While Schottky defects are the major structural point defect type present in most crystals with this structure, it is found that the silver halides, including AgBr, favor Frenkel defects (Fig. 2.5). 

The influence of light causes changes similar to that occurring in a photographic emulsion. The photons liberate electrons and these are trapped by interstitial silver ions, which exist as Frenkel defects, to form neutral silver atoms. Unlike the photographic process, the electrons are liberated by the Cu+ ions, which are converted to Cu2+ ions (CuAg) in the process ... 

F. C. Brown, The Photographic Process, in Treatise on Solid State Chemistry, Vol. 4, Reactivity of Solids, N. B. Hannay, Ed., Plenum, New York, 1976, Chapter 7. 

Photoinduced electron transfer reactions between surface bound dye molecules and semiconductor electrodes are important for practical as well as fundamental reasons. Absorption of light by the dye can improve the spectral response of the semiconductor and these systems are models for the photographic process (47-511. MDC surfaces are excellent substrates for studying electron injection into the conduction band of the semiconductor. 

Dickinson, H. O. Review of optical sensitizing. J. photographic. Sci. 2, 50 (1954). Mees, K. The theory of the photographic process. Rev. edit. New York Macmillan Company 1954. 

Diazoazoles, pyrazoles, and imidazoles also found applications in the photographic processes as precursors of triazenes, which are useful as additives for developers in color photography (73GEP2253615). In the texile industry, azo dyes obtained from diazopyrazoles showed dyeing properties on cotton, wool, and nylon 6 (47USP2420791 82MI1). Also, 1,3-ditetrazolyltriazene improved dyability and the feel of polyacrylonitrile filaments (58BRP796294). 

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