Editing Magic lantern (section)

==Technology==
[[File:1721? Jacob 's Gravesande - Physices Elementa Mathematica.jpg|thumb|A page of [[Willem 's Gravesande]]'s 1720 book ''Physices Elementa Mathematica'' with Jan van Musschenbroek's magic lantern projecting a monster. The depicted lantern is one of the oldest known preserved examples, and is in the collection of [[Museum Boerhaave]], Leiden]]

===Apparatus===
The magic lantern used a concave mirror behind a light source to direct the light through a small rectangular sheet of glass—a "lantern slide" that bears the image—and onward into a lens at the front of the apparatus. The lens is adjusted to focus the plane of the slide at the distance of the projection screen, which can be simply a white wall, and it forms an enlarged image of the slide on the screen.<ref name="ReferenceA">Pfragner, Julius. "An Optician Looks for Work". The Motion Picture: From Magic Lantern to Sound. Great Britain: Bailey Brothers and Swinfen Ltd. 9-21. Print.</ref> Some lanterns, including those of [[Christiaan Huygens]] and Jan van Musschenbroek, used three lenses for the [[objective (optics)|objective]].<ref>{{cite magazine|title=De toverlantaarn in Nederland|first=Daan|last=Buddingh|magazine=Het Photohistorisch Tijdschrift|issue=2|date=2007|trans-title=The Magic Lantern in the Netherlands|url=https://www.luikerwaal.com/newframe_uk.htm?/nederland1_uk.htm|access-date=2022-09-16}}</ref><ref>{{cite journal|title=The Tour of the World by Magic Lantern: Eugene Danguy's Diaphorama|last=Mannoni|first=Laurent|journal=The New Magic Lantern Journal|volume=11|issue=3|date=December 2012|url=https://www.magiclantern.org.uk/new-magic-lantern-journal/item.php?id=4009761|access-date=2022-09-16}}</ref>

Biunial lanterns, with two objectives, became common during the 19th century and enabled a smooth and easy change of pictures. [[Stereopticon]]s added more powerful light sources to optimize the projection of photographic slides.<ref>{{Cite web |title=Biunial and Triunial Magic Lanterns |url=https://www.luikerwaal.com/newframe_uk.htm?/biunial_uk.htm |access-date=2022-09-16 |website=De Luikerwaal}}</ref>

===Slides===
Originally the pictures were hand painted on glass slides. Initially, figures were rendered with black paint but soon transparent colors were also used. Sometimes the painting was done on oiled paper. Usually black paint was used as a background to block superfluous light, so the figures could be projected without distracting borders or frames. Many slides were finished with a layer of transparent lacquer, but in a later period cover glasses were also used to protect the painted layer.<ref>{{cite web|url=http://www.luikerwaal.com/platen1_uk.htm|title=All about lantern slides (1)}}</ref> Most handmade slides were mounted in wood frames with a round or square opening for the picture.<ref>{{cite web|url=http://www.luikerwaal.com/platen2_uk.htm|title=All about magic lantern slides (2)|website=www.luikerwaal.com}}</ref>

[[File:10 Story about a boy falling in a barrel of honey.JPG|thumb|left|A paper rimmed mass-produced slide]]
After 1820 the manufacturing of hand colored printed slides started, often making use of [[decalcomania]] transfers.<ref>{{cite web|url=http://www.luikerwaal.com/platen1_uk.htm#decal|title=All about lantern slides (1)|website=De Luikerwaal}}</ref> Many manufactured slides were produced on strips of glass with several pictures on them and rimmed with a strip of glued paper.<ref name="Timby2016">{{cite journal|url=https://www.academia.edu/23363210|title=Glass Transparencies: Marketing Photography's Luminosity and Precision|last=Timby|first=Kim|author-link=Kim Timby|year=2016|journal=PhotoResearcher|issue=25 }}</ref>

The first photographic lantern slides, called ''hyalotypes'', were invented by the German-born brothers Ernst Wilhelm (William) and [[Frederick Langenheim|Friedrich (Frederick) Langenheim]] in 1848 in [[Philadelphia]] and patented in 1850.<ref name="Timby2016"/><ref>{{Cite web|url=https://patents.google.com/patent/US7784A/en|title=Improvement in photographic pictures on glass}}</ref><ref>{{Cite web|url=http://historiccamera.com/cgi-bin/librarium2/pm.cgi?action=app_display&app=datasheet&app_id=1799&|title=William and Frederick Langenheim at Historic Camera|website=Historic Camera}}</ref>

===Light sources===
Apart from sunlight, the only light sources available at the time of invention in the 17th century were candles and oil lamps, which were very inefficient and produced very dim projected images. The invention of the [[Argand lamp]] in the 1790s helped to make the images brighter. The invention of [[limelight]] in the 1820s made them even brighter, emitting about 6000-8000 [[Lumen (unit)|lumens]].<ref>[https://www.canon-europe.com/view/laterna-magica/ Laterna Magica – the simple device that changed the way we view the world]</ref> The invention of the intensely bright electric [[arc lamp]] in the 1860s eliminated the need for combustible gases or hazardous chemicals, and eventually the incandescent electric lamp further improved safety and convenience, although not brightness.<ref name="ReferenceB">Waddington, Damer. "Introduction". Panoramas, Magic Lanterns and Cinemas. Channel Islands, NJ: Tocan Books. xiii-xv. Print.</ref>