The Optimum Photographic Representation of Brightnesses in Interior Scene

Abstract

This paper describes a theoretical and practical solution to the problems of reproducing the apparent brightne ses of interior scenes through the medium of achromatic prints. The photographic process required to gain the “optimumprint” is simple and economic and can be undertaken with conventional materials and equipment.

It can be shown that the optimum objective tone-reproduction of an achromatic scene, of log-luminance range 1.9, is a practical possibility which leads directly to an excellent subjective match when the facsimile is viewed under appropriate conditions.

Conclusions drawn from this investigation indicate that an “optimum-print” is restricted to the representation of relative brightnesses of a scene, but if such a print is viewed via a field-restricting aperture fitted with a selection of neutral-density filters, it is possible to adapt the eye of the observer so that absolute scene-brightnesses may be simulated with a high degree of realism. It is suggested that the techniques outlined in this paper could be used by relatively semi-skilled workers to furnish photographic reproductions of interior scenes with a high degree of quality and subjective accuracy. A machineprocess, controlled by punched-card, has been established for the purpose of bulk production of “optimum-prints".