There is provided a high precision device for measuring the color of non-self-luminous or self-luminous objects having interchangeable optical geometries for conversion from one optical geometry to another. The device interchanges a plurality of modules, each having at least one optical geometry...http://www.google.de/patents/US5754283?utm_source=gb-gplus-sharePatent US5754283 - Color measuring device having interchangeable optical geometries
