Grand magic lantern exhibition - Public domain graphic arts, Library of Congress

The lantern slides first produced for the 17th century's “magic lantern” devices. The magic lantern, also known by its Latin name Lanterna Magica, an image projector that used pictures on transparent plates (usually made of glass), one or more lenses, and a light source, used for entertainment. The earliest slides for magic lanterns consisted of hand-painted images on glass, made to amuse their audiences. After the invention of photography, lantern slides began to be produced photographically as black-and-white positive images, created with the wet collodion or a dry gelatine process. Photographic slides were made from a base piece of glass, with the emulsion (photo) on it, then a matte over that, and then a top piece of a cover glass. Sometimes, colors have been added by hand, tinting the images. Lantern slides created a new way to view photography: the projection of the magic lantern allowed for a large audience. Photographic lantern slides reached the peak of their popularity during the first third of the 20th century impacting the development of animation as well as visual-based education.