Slide projector

Slide projector
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. Reversal film was much in use, and supplied 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Photographic film slides and projectors have mostly been replaced by image files on digital storage media shown on a projection screen by using a video projector or simply displayed on a large-screen video monitor.
History
A continuous-slide lantern was patented in 1881. It included a dissolving views apparatus.
Components
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 slide
slide holder
focusing lens
A 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.
Types
Straight-tray slide projectors
Carousel slide projectors
Stack-loader slide projectors
Slide cube projectors
Dual slide projectors
Single slide projectors (manual form)
Dissolve projectors
Slide viewer projectors
Stereo slide projectors project two slides simultaneously with different polarizations, making slides appear as three-dimensional to viewers wearing polarizing glasses
Medium-format slide projectors
Large-format slide projectors for use on stages, at large events, or for architectural and advertising installations where high light output is needed.
Overhead projectors
Manufacturers
List of known manufacturers of slide projectors:
Agfa Gevaert, Germany (–1984) → Reflecta (1984–)
, Germany → Bosch; ceased production
Bausch & Lomb; ceased production
Bell & Howell / TDC, US: "Headliner"; ceased production
Braun AG, Germany: "D", "PA"; ceased production
Braun Foto Technik, Germany: "Paximat", "Multimag" → Reflecta
VEB DEFA, Germany: "Filius"→ VEB Gerätewerk Friedrichshagen: "Filius"; ceased production
Eastman Kodak (–2004): "Carousel-S", "Ektagraphic", "Ektapro" → Leica
Elmo, Japan
Enna, Germany; ceased production
Erno Photo, Germany; ceased production
VEB Feinmess, Germany; ceased production
Filmoli, Germany → Gebr. Martin, Germany; ceased production
Foto Quelle, Germany: "Revue"; ceased distribution
GAF, US; ceased distribution
Götschmann, Germany (1978–2009) → Gecko-Cam (2009–)
Hasselblad, Sweden; ceased production
HASPE, Germany; ceased production
Hähnel, Germany; ceased production
Inox, France: "Prestige" → Prestinox
, Germany: "Diafocus" → Leica
Leitz, Germany (1958–): "Prado" → Leica Projektion GmbH Zett Gerätewerk, Germany (1990–2004): "Pradovit", "Pradovit RT" → Leica Camera, Germany (2004–2006): "Pradovit"; ceased production
, Germany: "Fantax", "Diafant", "Fantimat"; ceased production
Malinski, Germany: "Prokyon", "Malicolor" → Pentacon
Minolta, Japan; ceased production
Minox, Germany: "Minomat"; ceased production
Navitar, US
Nikon, Japan; ceased production
Ernst Plank, Germany: "Noris", "Trumpf"; ceased production
Pentacon, Germany: "Aspectar", "Malicolor"; ceased production
Asahi Pentax, Japan; ceased production
Prestinox, France → Plawa Condor (1969–?); ceased production
Pouva, Germany; ceased production
RBT, Germany
Queen, Germany: "Automat"; ceased distribution
Reflecta, Germany: "Multimag"
Rollei, Germany (1960–2007): "Rolleiscop", "Rolleivision" → Franke & Heidecke, Germany (2007–2009): "Rolleivision" → DHW Fototechnik, Germany (2009–2015): "Rolleivision"; ceased production
Royal, Germany?; ceased distribution
Sankyo, Japan; ceased production
Sawyer's, US; company sold to GAF
, Italy → Bauer and Rollei; ceased production
Vicom
Vivitar, US
Voigtländer, Germany: "Perkeo" → Zett
Zeiss Ikon, Germany (1964/1969–): "Ikolux" → Zett
Zeiss Jena, Germany → Pentacon, Germany
Zett, Germany (1928–1989): "Fafix", "Zett", "Zettomat", "Perkeo" → Leica Projektion GmbH Zett Gerätewerk, Germany (1990–2004)
CBИTЯ3ъ, Russia: "ABTO"; ceased production
See also
Slide viewer
Carousel slide projector
Presentation slide
References
General references
Inline citations
Display devices
Slide projectors
de:Projektor#Durchlichtprojektion