Dietrich ZawischaContact

Criticism of Kueppers' Theory of Color

Harald Kueppers, an expert in colour printing and reproduction, holder of patents in that field, author of several books about colour, is cited as a great authority in the field of colour science by several German websites. Here is a link to his own site: Kueppers' Theory of Color.
For people interested in colour mixing and printing, the site may be of interest, but unfortunately, it contains some gross mistakes.

The quotations in the following text are taken from Kueppers' website.

The first blunder is on the page "The Functioning Principle of The Visual Organ". There is a schematic picture of the retina's cross section, the caption of which is

Cross section of the retina: rods (A), cones (B), cell nuclei of cone cells (C). Light passes first through the pigment epithelium (E) where the cell nuclei (D) are embedded.         (Retrieved January 24, 2014.)

In other people's eyes light which has passed the rods and cones of the retina is finally absorbed in the pigment epithelium.

The most remarkable feature of Kueppers is his disregard of experimental facts and established colour science.

On the same page he presents the following pictures:

Sensitivity regions of the 3 cone types Color perception attributed to the cone types

Today the cone fundamentals are very well known. The data published by Stockman and Sharpe (2000) have been used for the graph to the right; they can be downloaded from the site of the Colour & Vision Research Laboratory of the UCL (University College London).

The next quotations are from the section Colorimetry is The Only Solution For Electronic Manipulation of Color.

Still, it is a serious problem that the CIE system is based on arbitrary assumptions of the sensibility of the three cone types which do not correspond with reality. Based on his own research, H. Kueppers established that the maximal sensibility of the three cone types are not where the CIE systems is assuming, but at 448 nm for B, at 518 nm for G, and at 617 nm for R.

Kueppers passionately ignores the experimental data which are the basis of the CIE system. He really seems to believe that the colour matching functions of the CIE are only guesses!

Actually, colorimetry should put itself on an entirely new basis. The assumed maximal sensibility of the three cone types should be changed and optimized. Besides, one should part with the RGB ideology and take into account the scientific findings of the new Kueppers' Theory of Color.

A bold claim is at least a sign of good self-confidence!

Back to the index page