Colour Measurement

Abstract

MR. J. W. PERRY's remarks¹ directing attention to the difference between the calorimetric concepts which he calls χC.I.E. and χN are opportune. As he points out, there is at present no real justification for applying the results of measurements made under the original standard C.I.E. conditions to problems involving other conditions of observation, and if nevertheless we do so, we must clearly realize that this procedure is at best a makeshift pending the publication of more detailed information. There is a need for fundamental research on the whole subject of the colorimetry of wide field systems.