File:The American annual of photography (1922) (14779346204).jpg

Identifier: americanannualof36newy (find matches)
Title: The American annual of photography
Year: 1922 (1920s)
Authors:
Subjects: Photography
Publisher: New York : Tennant and Ward
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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ve As It Appears After Development. Always think of the first step, b, and the last step say, g,as corresponding to the shadows and highlights in the subjectphotographed, the intermediate steps corresponding to thevarious tones of the subject. The density of & is a measureof the detail giving power of the developer, while the differencebetween g and b gives the density contrast. In the case ofdevelopers required to render a minimum exposure, say forhigh speed photography, the difference in density between aand b should be as great as possible with enough differencebetween b and g to give a sufficiently contrasty print, butwith a developer intended for, say, line work, the density ofa should be as low as possible; that is, the developer should befree from fog, while that of b and g should be as great aspossible. Factors to be Considered zvhen Comparing Developers.An ideal developer is one which will develop rapidly, givegood contrast and shadow detail without producing chemical 192
Text Appearing After Image:
4>O o u ao CO < CO O fog, and which will deteriorate only slowly; that is, if it hasgood keeping qualities. Other factors are of less importance.The specifications of ideal developers for various purposes,of course, differ. For instance, if the most is to be securedfrom an under-exposed negative, it should be developed in atray w^ith a developer containing caustic alkali, this developerkeeping active for only a very short time. In the case ofamateur finishers and motion picture film laboratories, a de-veloper is required which will develop a normally exposed nega-tive in from 5 to 15 minutes, but the developer must also keepin active condition for 2 or 3 weeks. In order, therefore, to enable the reader to interpret the re-sults of his tests, it is necessary first to study the variouscharacteristics of a developer as follows: I. THE DEVELOPING POWER When we speak of developing power, we are using a some-what vague term in an attempt to sum up several characteristicsof the develop

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