Abstract

In order to develop a method of heterochromatic photographic photometry which can be used to compare line intensities at different wave lengths in the ultraviolet, the sensitivity, speed, contrast, scale, and fogging characteristics of six standard emulsions were studied in the region 4350-2144A. Light from a constant source (mercury vapor lamp or cadmium spark) was dispersed in a high aperture monochromator and the energy distribution was measured by a thermopile and d’Arsonval galvanometer. The light was diminished in intensity uniformly at all wave lengths by means of a diaphragm and screens. Density-log intensity and density-log time curves were plotted at fourteen wave lengths for each emulsion, in some cases for several times of development, and from these the values of intensity contrast and time contrast were measured. All plates showed a decreasing contrast with decreasing wave length, although some showed a minimum at 2800A, with somewhat increased contrast for a short distance at shorter wave lengths. All showed an increased speed at shorter wave lengths over that in the visible as far down as 2500A, when the speed for all except the Schumann plates decreased rapidly. Cramer contrast process plates, with extremely high contrast in the visible, showed greatly decreased contrast at shorter wave lengths, though even here the contrast was greater than that of the other plates. The reciprocity law was found to hold very closely with this plate at all wave lengths above 2500A (and possibly below), over the time and intensity range studied. Eastman Speedway plates showed fairly uniform speed and contrast down to 2500A. These two plates were found excellent for photometry, the first having high contrast and slow speed, and the second low contrast and high speed. They showed the least tendency to acquire chemical fog of any of the plates. The Schumann plates were found unsuitable for photographic photometry, having large variations in sensitivity over their surfaces. Data are also given for several oil-coated emulsions in the region 2700-2144A. Oil can be used not only to increase speed and contrast at wave lengths below 2500, but to make these factors vary less with wave length.

© 1925 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. Buisson and Fabry, Rev. d. Optique,  3, p. 1; 1924. Harrison and Hesthal, This Journal,  8, p. 471; 1924.
  2. Helmick, This Journal,  9, p. 521; 1924.
  3. Davis and Walters, , p. 13; 1922.
  4. Harrison, This Journal,  11, p. 113; 1925.
  5. Harrison and Forbes, This Journal,  10, p. 1; 1925.
  6. Forbes and Harrison, This Journal,  11, p. 99; 1925.
  7. Harrison, Phys. Rev.,  24, p. 466; 1924.
    [CrossRef]
  8. Harrison, This Journal,  10, p. 157; 1925.
  9. Harrison, Phys. Rev.,  25, p. 768; 1925.
    [CrossRef]
  10. Leimbach, Zeits. wiss. Phot.,  7, pp. 157, 181; 1909.
  11. Jones and Schoen, This Journal,  7, p. 213; 1923.

1925 (5)

Harrison, This Journal,  11, p. 113; 1925.

Harrison and Forbes, This Journal,  10, p. 1; 1925.

Forbes and Harrison, This Journal,  11, p. 99; 1925.

Harrison, This Journal,  10, p. 157; 1925.

Harrison, Phys. Rev.,  25, p. 768; 1925.
[CrossRef]

1924 (3)

Buisson and Fabry, Rev. d. Optique,  3, p. 1; 1924. Harrison and Hesthal, This Journal,  8, p. 471; 1924.

Helmick, This Journal,  9, p. 521; 1924.

Harrison, Phys. Rev.,  24, p. 466; 1924.
[CrossRef]

1923 (1)

Jones and Schoen, This Journal,  7, p. 213; 1923.

1909 (1)

Leimbach, Zeits. wiss. Phot.,  7, pp. 157, 181; 1909.

Buisson,

Buisson and Fabry, Rev. d. Optique,  3, p. 1; 1924. Harrison and Hesthal, This Journal,  8, p. 471; 1924.

Davis,

Davis and Walters, , p. 13; 1922.

Fabry,

Buisson and Fabry, Rev. d. Optique,  3, p. 1; 1924. Harrison and Hesthal, This Journal,  8, p. 471; 1924.

Forbes,

Harrison and Forbes, This Journal,  10, p. 1; 1925.

Forbes and Harrison, This Journal,  11, p. 99; 1925.

Harrison,

Forbes and Harrison, This Journal,  11, p. 99; 1925.

Harrison, This Journal,  11, p. 113; 1925.

Harrison and Forbes, This Journal,  10, p. 1; 1925.

Harrison, This Journal,  10, p. 157; 1925.

Harrison, Phys. Rev.,  25, p. 768; 1925.
[CrossRef]

Harrison, Phys. Rev.,  24, p. 466; 1924.
[CrossRef]

Helmick,

Helmick, This Journal,  9, p. 521; 1924.

Jones,

Jones and Schoen, This Journal,  7, p. 213; 1923.

Leimbach,

Leimbach, Zeits. wiss. Phot.,  7, pp. 157, 181; 1909.

Schoen,

Jones and Schoen, This Journal,  7, p. 213; 1923.

Walters,

Davis and Walters, , p. 13; 1922.

Phys. Rev. (2)

Harrison, Phys. Rev.,  24, p. 466; 1924.
[CrossRef]

Harrison, Phys. Rev.,  25, p. 768; 1925.
[CrossRef]

Rev. d. Optique (1)

Buisson and Fabry, Rev. d. Optique,  3, p. 1; 1924. Harrison and Hesthal, This Journal,  8, p. 471; 1924.

This Journal (6)

Helmick, This Journal,  9, p. 521; 1924.

Harrison, This Journal,  11, p. 113; 1925.

Harrison and Forbes, This Journal,  10, p. 1; 1925.

Forbes and Harrison, This Journal,  11, p. 99; 1925.

Harrison, This Journal,  10, p. 157; 1925.

Jones and Schoen, This Journal,  7, p. 213; 1923.

Zeits. wiss. Phot. (1)

Leimbach, Zeits. wiss. Phot.,  7, pp. 157, 181; 1909.

Other (1)

Davis and Walters, , p. 13; 1922.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

F. 1
F. 1

Characteristic curves for the fastest and slowest emulsions, exposed for ten seconds to light of wave length 2537A. Curve (1), Cramer Contrast Process Plate; Curve (3), Eastman Speedway Plate. The plates were developed together.

F. 2
F. 2

Curves showing the variation of contrast with wave length for the Cramer Contrast Process plate, for three times of development. Also curve showing the degree of departure of this emulsion from fulfillment of the reciprocity law, indicated by the dotted line.

F. 3
F. 3

Curves showing the variation of contrast with wave length for most of the emulsions studied, all developed for five minutes except (4). (1) Cramer Contrast Process plate; (2) Seed 23 plate; (3) Eastman Speedway plate; (4) Hilger Schumann plate; (5) Wratten and Wainwright Panchromatic plate; (1a) Plate (1) bathed with Lab. Lub. oil; (1b) Plate (1) bathed with Nujol; (3a) Plate (3) bathed with Lab. Lub. oil.

F. 4
F. 4

Curves showing the variation of speed with wave length for the eight emulsions shown in Fig. 3.

F. 5
F. 5

Sensitivity curves for a typical Cramer Contrast Process plate, showing the densities produced at different wave lengths by three energy densities.

F. 6
F. 6

Typical characteristic curves for several emulsions exposed to light of, wave length 2144A for ten seconds. The emulsions are marked to correspond with those in Fig. 3.

Tables (3)

Tables Icon

Table 1 Intensities of arc and spark lines used (Maxima 7-15 from the mercury arc; maxima 1-6 from the cadmium spark)

Tables Icon

Table 2 Wire Screen Transmissions

Tables Icon

Table 3 Chemical fog on plates