Jumelle Jumelle Lux Juwel Kalloscop Kalloscope (Richard) Keystone View Company Kilburn brothers Kilburn viewing case Kilburn, William Edward Knight, George & Sons Kolibri Kromskop Langenheim brothers Latimer Clark system Laurent Lazy tong Le Deley, Ernest Lee, James Legendre, Louis Lenticular stereoscope Leporello stereoscope Leroy, Lucien Lévy patent Lewis family Lewis, Henry J. patent Lewis, William H. combined stereoscope Lewis, William H. patent graphoscope Lissigret Listograph Lithograph stereoview Lohire London Stereoscopic Company Long-focus