Metropolitan Syndicate Press Mexican stereoscope Mignon-Stéréo Mignoscope Minimus Mirascope Miroplast Mirror stereoscope Moigno, Abbé Monocle stéréoscope Motoscope Multi-view stereoscope Multicolore Multiphote Multiplast Mundoplast Murray & Heath Murray & Heath registration Musique Automatique N. P. G. Nain Napoleon III style Natural stereoscope Negative Negretti & Zambra Negretti & Zambra patent Neue Photographische Gesellschaft New York Stereoscopic Company Newman, John Frederick Noé, Henri Nunn patent Oculus Omnicolore