Photographic Granularity and Graininess VI Performance Characteristics of the Variable-Magnification Graininess Instrument*

Abstract

Data obtained with the variable-magnification graininess instrument described in Part V of this series of communications are given showing the variation of graininess as a function of the luminance of the test field, the luminance of the various components of the observer’s field, the viewing distance, and the angular subtense of the test field. On the basis of these data, standard conditions for the various variables are established for the measurement of graininess. Graininess measurements in terms of blending magnification at a constant viewing distance are compared with graininess measurements in terms of blending distance at a constant magnification.