File:The American annual of photography (1914) (14757766176).jpg

Identifier: americanannualof28newy (find matches)
Title: The American annual of photography
Year: 1914 (1910s)
Authors:
Subjects: Photography
Publisher: New York : Tennant and Ward
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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SON. EDWARD II. WESTON. a temperature of from 90° to 100° until the soluble gelatinebegins to ooze out from under the piece of tissue, strip off thetissue while both pieces of paper are kept under the surfaceof the water. Your picture is now supported by the transferpaper, and at this stage looks like a hopeless mass of meltedgelatine. Rock the tray containing the print and the solublegelatine will gradually wash off leaving the picture in all itsdetails. If the picture is a little too dark, raise the tempera-ture of the water, as high as 115° doing no harm. Thehigher the temperature the more will wash oft* and the lighterthe print for a given exposure. After the picture is developedthe bichromate left in the film is removed by placing the printfor a few minutes in a solution of common alum of aboutthree to five per cent and then washed to remove the alum.The print is now ready to hang up to dry. There is considerable latitude in the degree of contrast that 300
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o can be obtained by the carbon process, as the weaker thesensitizer the more contrast, and the stronger the sensitizerthe less contrast. The sensitiveness varies in proportion tothe strength of sensitizer used. In case still more contrast isdesired, or a rather thin negative such as is used for develop-ing paper is to be printed use the following sensitizer. Water 32 Oz. Bichromate Potash ^ Oz. Citric Acid 10 grains. Aqua Ammonia 20 minims. This will give a rather slow printing, but very brilliant work-ing tissue, and will give satisfactory prints from negativesthat would otherwise be useless. To reduce the contrast forunduly harsh negatives use five per cent bichromate sensitizerand print them through a sheet of violet colored glass. Aneasy way to make such a glass is to fix out an old dry plateand stain it with any strong violet dye such as methyl violetor crystal violet. Printing through a yellow glass will alsoincrease the contrast if necessary. It is evident that considerable co

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