A large-format slide projector (also often called large-format projector or large-image projector) is a kind of
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 ...
for large image projection which has a very powerful
light source
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terah ...
(up to 12 thousand watts using
arc lamps
An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc).
The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, ...
). Therefore, it is necessary to use a large slide format to protect the slide material from overheating during the projection process (even when the light is filtered to only visible light and the slide is cooled with strong slide cooling fans). Slide formats include 18 × 18 cm (7.1 × 7.1") or 24 × 24 cm (9.4 × 9.4").
Projection art
These formats are so large that it is possible to project slides painted with heat resistant translucent colours as a special kind of art (projection art). The light output of the projector is so enormous that it is possible to cover whole buildings with an artistic cover of light.
History
The first large-format slide projectors were built in the middle of the 20th century as background projectors for theaters and opera houses. The artists
Günther Schneider-Siemssen
Günther Schneider-Siemssen (7 June 1926 – 2 June 2015) was a German-born Austrian scenic designer, working as the chief designer for all Austrian State Theatres and the Salzburg Festival, where he created 28 productions for Herbert von Karajan ...
,
and Professor Svoboda used the large format slide projectors as stage projectors in their artwork. In good cooperation with the technician Ing. Ludwig Pani, they realized the first large format projections as an integrated part of their artwork.
Manufacturers
Large scale image projectors have been pioneered by manufacturers Pani, Hardware Xenon and PIGI. These projectors are usually described as scenic projectors, and project light through photographic or inkjet media, unlike video projectors that reflect light off of LCD or DMD (digital micro mirror, sometimes referred to as DLP) devices. Despite advancements in video technology, still image projectors are still capable of many times the luminous output of video projection devices. Scenic projectors sometimes utilize r