Carl Pulfrich

Carl P. Pulfrich (September 24, 1858 in Burscheid, Rhine Province, Kingdom of Prussia – August 12, 1927 in Baltic Sea, drowned when his canoe capsized) was a German physicist, noted for advancements in optics made as a researcher for the Carl Zeiss company in Jena around 1880, and for documenting the Pulfrich effect,[1] a psycho-optical phenomenon that can be used to create a type of 3-D visual effect.

[4] Leica Geosystems sponsors the "Carl Pulfrich Award", to honour advancements in the fields of photogrammetry, remote sensing, and earth imaging.

In solchen für den Augenarzt besonders beachtenswerten Fällen konnte jedesmal eine mehr oder weniger grosse, durch einseitigen Gebrauch oder andere Ursachen erworbene Ungleicheit der beiden Augen nachgewiesen werden.”[There are, as we have found out, people who can perceive the circulation of the pointer without using a neutral density filter.

In these cases, relevant to the ophthalmologist it was always possible to demonstrate a difference between the two eyes, due to unilateral use (Translator’s remark: Pulfrich refers to amblyopia) or other causes.

He wondered why the stereo-effect was not noted earlier because of the abundance of swinging clock pendulums: “Wenn man bedenkt mit welch einfachen Mitteln die Erscheinung der kreisenden Marke hervorgerufen werden kann, so kann man sich nur darüber wundern, dass sie anscheinend nicht schon früher einmal beobachtet worden ist, wozu doch jeder Uhrenladen die Gelegenheit bietet.”[If one considers the simple means used to produce the phenomenon of the circulating pointer, one wonders why this observation has not been made earlier, particularly as every shop selling clocks offers this opportunity.