Ridderhof’s Anaglyphs study of descriptive geometry
Anaglyphs, used in the study of descriptive geometry in secondary schools. Manufactured by W.C.A. Ridderhof, Teacher 1st H.B.S. 5 years, The Hague. January 1927. The set consists of the Original Anaglyph glasses, 10 plates and a description.
Anaglyph is a method to view Stereo. Anaglyph shows two separate geometric spatial figures on top of each other, a red image for the left eye and an image for the right. When viewing these images are split again, by viewing them with special glasses. These so-called ‘anaglyph glasses’ (glasses with a red filter on the left and a cyan filter on the right) filter out two different images from the anaglyph image. The left eye only sees the image in red, and the right eye only sees the image in cyan (green plus blue). In earlier applications green was still used as the filter color, nowadays cyan is the most commonly used color.