The tradition of slide projection goes back hundreds of years to the magic lantern. While the materials slides and projectors are made of have changed—from glass and metal to plastic—the basic function of the apparatuses remained the same.
Magic LanternThe invention of the first image projection device is attributed to Christian van Huygens in 1659. The astronomer used convex lenses and a lamp to project a sketch of a group of skeletons. A slightly more advanced version, pictured, was used for phantasmogoria shows in the nineteenth century. (image: explow.com)
Kodaslide Projector, 1939-1947Five years after introducing the color photography process called Kodachrome, which created perfectly registered colors on transparencies, Kodak came out with the Kodakslide projector. The first model had gravity-loading from the top. The second model (pictured) featured side-load, in which a new slide pushed another out the other side. (image: relicsandcollectibles/photobucket.com)
Kodak Carousel, 1961This iconic version of the projector allowed for 81 slides per tray and had a remote control to go forward, reverse, and focus. (image: rhizome.org)
Kodak Ektagraphic, 1967The Ektagraphic projector was the first professional version for the high-end market. A version of this model stayed in production until 2004.
What's insideThe plastic housing of the Ektagraphic projector contains a motor, a plastic wheel, plus various springs, screws and levers.
Like the magic latern, the Ektagraph has a lens at its core.