The American annual of photography . e, which is very sensitive to bromide, shadow detail inthe negative is lost. Pyro, Elon, and Ortol are less sensitiveto bromide and should therefore predominate in a negativedeveloper. Pyro oxidizes rapidly and gives stain unless anexcess of sulphite is added, which in turn tends to producefog. For motion picture positive work the effect of the ac-cumulated potassium bromide is of less importance, since thiscan be cornpensated for by increasing the printing exposure. In tank work, as the developer becomes exhausted as a resultof performing useful work, it i
The American annual of photography . e, which is very sensitive to bromide, shadow detail inthe negative is lost. Pyro, Elon, and Ortol are less sensitiveto bromide and should therefore predominate in a negativedeveloper. Pyro oxidizes rapidly and gives stain unless anexcess of sulphite is added, which in turn tends to producefog. For motion picture positive work the effect of the ac-cumulated potassium bromide is of less importance, since thiscan be cornpensated for by increasing the printing exposure. In tank work, as the developer becomes exhausted as a resultof performing useful work, it is customary to increase the timeof development by about one minute per day so as to main-tain a coiiJtant contrast of the negatives. Tank developers should be given a thorough exhaustion testby developing camera exposed or flashed films in a deep glasstank containing about half a gallon of solution, a sufficientnumber of films being developed daily so as to correspond toan average daily run in a fifty or one hundred gallon tank. 212. STUDY. JANE REECE. 213 Graded strip tests should also be made daily and developed toa given density contrast, the density of the lowest steps whichare a measure of the detail giving power being carefully noted,(c). The alkalinity should not be excessive; otherwise, theacid fixing bath soon becomes neutral as a result of the neu-tralization of the acid by the alkali in the developer carriedover by the films. The following example illustrates the method of testing on a Deep Tank Developer Formula for Amateur formula submitted was tested against the standardformula by first developing flashed sheets of NC film for 15minutes at 70° F, the tests being repeated after allowing thedevelopers to stand in open trays over night and diluting tothe original volume to compensate for evaporation. The re-sults were as follows: 1st Day Density Test Formula. ... Standard Formula This preliminary test showed that the deve
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