A slide projector is an opto-mechanical device for showing photographic slides.
35 mm slide projectors, direct descendants of the larger-format magic lantern, first came into widespread use during the 1950s as a form of occasional home entertainment; family members and friends would gather to view slide shows, which typically consisted of slides snapped during vacations and at family events. Slide projectors were also widely used in educational and other institutional settings.
Photographic film slides and projectors have mostly been replaced by image files on digital storage media shown on a projection screen by using a video projector or simply displayed on a large-screen video monitor.
A projector has four main elements:
electric incandescent light bulb or other light source (usually fan-cooled)reflector and "condensing" lens to direct the light to the slideslide holderfocusing lensA flat piece of heat-absorbing glass is often placed in the light path between the condensing lens and the slide, to avoid damaging the latter. This glass transmits visible wavelengths but absorbs infrared. Light passes through the transparent slide and lens, and the resulting image is enlarged and projected onto a perpendicular flat screen so the audience can view its reflection. Alternatively, the image may be projected onto a translucent "rear projection" screen, often used for continuous automatic display for close viewing. This form of projection also avoids the audience interrupting the light stream by casting their shadows on the projection or by bumping into the projector.
straight-tray slide projectorsround-tray slide projectorsstack-loader slide projectorsslide cube projectorsdual slide projectorssingle slide projectors (manual form)dissolve projectorsviewer slide projectorsstereo slide projectors project two slides simultaneously with different polarizations, making slides appear as three-dimensional to viewers wearing polarizing glassesmedium-format slide projectorslarge-format slide projectors for use on stages, at large events, or for architectural and advertising installations where high light output is needed.overhead projectorsList of known manufacturers of slide projectors:
Agfa Gevaert, Germany (-1984) -> Reflecta (1984-)Bauer, Germany -> Bosch; ceased productionBausch & Lomb; ceased productionBell & Howell / TDC, USA: "Headliner"; ceased productionBraun AG, Germany: "D", "PA"; ceased productionBraun Foto Technik, Germany: "Paximat", "Multimag" -> ReflectaVEB DEFA, Germany: "Filius" -> VEB Gerätewerk Friedrichshagen: "Filius"; ceased productionEastman Kodak (-2004): "Carousel-S", "Ektagraphic", "Ektapro" -> LeicaElmo, JapanEnna, Germany; ceased productionErno Photo, Germany; ceased productionVEB Feinmess, Germany; ceased productionFilmoli, Germany -> Gebr. Martin, Germany; ceased productionFoto Quelle, Germany: "Revue"; ceased distributionGAF, USA; ceased distributionGötschmann, Germany (1978-2009) -> Gecko-Cam (2009-)Hasselblad, Sweden; ceased productionHASPE, Germany; ceased productionHähnel, Germany; ceased productionInox, France: "Prestige" -> PrestinoxKindermann, Germany: "Diafocus" -> LeicaLeitz, Germany (1958-): "Prado" -> Leica Projektion GmbH Zett Gerätewerk, Germany (1990-2004): "Pradovit", "Pradovit RT" -> Leica Camera, Germany (2004-2006): "Pradovit"; ceased productionLiesegang, Germany: "Fantax", "Diafant", "Fantimat"; ceased productionMalinski, Germany: "Prokyon", "Malicolor" -> PentaconMinolta, Japan; ceased productionMinox, Germany: "Minomat"; ceased productionNavitar, USANikon, Japan; ceased productionErnst Plank, Germany: "Noris", "Trumpf"; ceased productionPentacon, Germany: "Aspectar", "Malicolor"; ceased productionAsahi Pentax, Japan; ceased productionPrestinox, France -> Plawa Condor (1969-?); ceased productionPouva, Germany; ceased productionRBT, GermanyQueen, Germany: "Automat"; ceased distributionReflecta, Germany: "Multimag"Rollei, Germany (1960-2007): "Rolleiscop", "Rolleivision" -> Franke & Heidecke, Germany (2007-2009): "Rolleivision" -> DHW Fototechnik, Germany (2009-2015): "Rolleivision"; ceased productionRoyal, Germany?; ceased distributionSankyo, Japan; ceased productionSawyer's, USA; company sold to GAFSilma, Italy -> Bauer and Rollei; ceased productionTAV SimdaVicomVivitar, USAVoigtländer, Germany: "Perkeo" -> ZettZeiss Ikon, Germany (1964/1969-): "Ikolux" -> ZettZeiss Jena, Germany -> Pentacon, GermanyZett, Germany (1928-1989): "Fafix", "Zett", "Zettomat", "Perkeo" -> Leica Projektion GmbH Zett Gerätewerk, Germany (1990-2004)CBИTЯ3ъ, Russia: "ABTO"; ceased productionThe Slide Projector Web Series
