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Ernst Abbe was a notable collaborator of Zeiss. Abbe was a physicist and mathematician who developed Theory of microscope optics. He also worked with Zeiss to develop new microscopes, including the apochromatic microscope. Abbe's work on microscope optics had a significant impact on the development of microscopy, and his collaboration with Zeiss helped to make Zeiss one of the leading manufacturers of microscopes in the world.