Das umfangreichste derzeit erhältliche Werk zum Thema Farben-jetzt als preisgünstige
Paperback-Ausgabe! Diskutiert werden alle Aspekte des Lichts, der Farben und der …

The effect to be described in this paper was discovered in attempting to develop an
apparatus for measuring the area of the eye pupil, using a photometric principle. The idea …

By means of the two-colour threshold method the threshold response of the rod or dark-
adapting visual mechanism can be followed to relatively high field intensities. From the …

The second part of the NPL's colour-matching investigation was devoted to determining
average colour-matching properties in a large (10° diameter) bipartite matching field, and …

I am most sensible of the honor of addressing this meeting and of the generosity of the
National Academy of Sciences in bringing me here as their guest. The in-vitation to …

It is now well established that light rays of the same spectral character and physical intensity
entering the eye through different points of the pupil may produce visual impressions which …

By the brightness difference threshold is ordinarily understood the least perceptible
difference of brightness of two contiguous test-fields when the brightness of one of these has …

Introduction.-The main reasons for re-examining the C.. E. standard photometric and
clorimetric data for the average eye were:(a) doubts about the correctness of the standard …

It has been found by the writer, in collaboration with BH Crawford (1933), that light rays
entering the eye pupil near its periphery are less efficient in producing the impression of …

A modified Helmholtz line-element in brightness- colour space Page 1 Proceedings of the
Physical Society A modified Helmholtz line-element in brightnesscolour space To cite this article …