The study was an investigation of the effect of different developers on contrast, grain, tonal range, density and sharpness in 35mm film and their effect on contrast and density in photographic paper.It was theorized that all normal developers do not react exactly the same, Therefore, merely changing developers would cause a significant visual change in each of the above-mentioned areas.To test the hypotheses a tightly controlled experiment was conducted using eleven normal film developers and ten normal paper developers. These developers were tested on Tri-X film, and on Oriental, Polycontrast and Polycontrast RC paper.All processing steps, except the developer, for both film and paper were standardized. A still life was used as the subject for all pictures. A densitometer was used to measure the actual differences in base density, contrast range and overall density caused by changing from one developer to the next. Prints were then made using a standard exposure time determined by zone system tests, and these prints were given to three groups of coders representing experts, advanced photo students and amateurs, for visual ranking in each of the areas being tested. The rankings obtained from these three groups were then statistically checked for a significant similarity at the .05 level.For the photographic paper tests, one negative was chosen from the film tests and used for all prints. Pictures were made on each of the three papers and developed in each of the ten normal developers under strict controls. These prints were then ranked for contrast and density changes by the three groups of coders. The rankings were subjected to the same statistical tests used for the film rankings.The film rankings proved significant at the .01 level in all areas except grain. This indicates just changing developers will cause a visually significant change in contrast, density, tonal range and sharpness. The grain tests were inconclusive, but they indicated under extreme enlargement changing developer alone will not have significant effect on the actual amount of grain.The results of the film tests were charted so that the effect of each developer could be compared directly with each of the other developers.The rankings on paper developers proved to be significant at the .01 level for density and at the .05 level for contrast, indicating there is a significant visual change in both areas caused just by changing the developer. The tests also indicated the density change is controlled by the photo paper itself, while the contrast change is controlled by the developer. These results were also charted for easy comparison.The study led the researcher to accept the hypotheses stated at the beginning, with a slight modification concerning changes in the actual amount of grain.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/182309 |
| Date | January 1980 |
| Creators | Adams, William Jenson |
| Contributors | Heintzelman, Robert W. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | iv, 67, [26] leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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