Abstract

A photoelectric scanning instrument is described which gives granularity values in terms that can be converted into the graininess values that would be obtained by an observer viewing a magnified image of the sample under standard conditions. The procedure is to determine the critical scanning aperture that results in a signal corresponding to the threshold-gradient sensitivity of the eye for the density of the sample. The techniques for making two types of routine graininess measurements are described in detail. Class I measurements give the graininess of samples at a density of 0.8. Class II measurements give granularity numbers that indicate the relative graininess to be expected of matched prints made from the negatives.

© 1957 Optical Society of America

Photographic Granularity and Graininess. VIII.* A Method of Measuring Granularity in Terms of the Scanning Area Giving a Threshold Luminance Gradient†

L. A. Jones, G. C. Higgins, and K. F. Stultz
J. Opt. Soc. Am. 45(2) 107-112 (1955)

Photographic Granularity and Graininess†,*II. The Effects of Variations in Instrumental and Analytical Techniques

Loyd A. Jones and George C. Higgins
J. Opt. Soc. Am. 36(4) 203-227 (1946)

Photographic Granularity and Graininess. VII. A Microphotometer for the Measurement of Granularity*

L. A. Jones and G. C. Higgins
J. Opt. Soc. Am. 41(3) 192-200 (1951)

Photographic Granularity and Graininess*III. Some Characteristics of the Visual System of Importance in the Evaluation of Graininess and Granularity

Loyd A. Jones and George C. Higgins
J. Opt. Soc. Am. 37(4) 217-263 (1947)

The Relationship Between the Granularity and Graininess of Developed Photographic Materials*

Loyd A. Jones and George C. Higgins
J. Opt. Soc. Am. 35(7) 435-457 (1945)