The Ives Kromskop
One of the most remarkable stereoscopes ever produced commercially was the Ives Kromskop (Patent #531,040, Dec 18, 1894). In it, three stereoscopic glass positives made from negatives exposed through red, green, and blue filters are optically superimposed to give a full color image of remarkable quality. It was more than ten years prior to the introduction of relatively crude full color plates such as the Autochrome.
