Projector
[citation needed] In the early 11th century, Arab physicist Ibn al-Haytham (Alhazen) described experiments with light through a small opening in a darkened room and realized that a smaller hole provided a sharper image.
An early variation was described in 1584 by Jean Prevost in his small octavo book La Premiere partie des subtiles et plaisantes inventions.
He suggested to take special care that the figures look lively: with horses raising their front legs as if they were jumping and soldiers with drawn swords, a dog chasing a hare, etcetera.
[8] Régnier compared the mind of an old nagger with the lantern's effect of birds, monkeys, elephants, dogs, cats, hares, foxes and many strange beasts chasing each other.
[9] John Locke (1632–1704) referred to a similar device when wondering if ideas are formed in the human mind at regular intervals,"not much unlike the images in the inside of a lantern, turned round by the heat of a candle."
Many modern electric versions of this type of lantern use all kinds of colorful transparent cellophane figures which are projected across the walls, especially popular for nurseries.
[13] A theory known as the Hockney-Falco thesis claims that artists used either concave mirrors or refractive lenses to project images onto their canvas/board as a drawing/painting aid as early as circa 1430.
[15] Around 1420 the Venetian scholar and engineer Giovanni Fontana included a drawing of a person with a lantern projecting an image of a demon in his book about mechanical instruments "Bellicorum Instrumentorum Liber".
[16] The Latin text "Apparentia nocturna ad terrorem videntium" (Nocturnal appearance to frighten spectators)" clarifies its purpose, but the meaning of the undecipherable other lines is unclear.
In 1437 Italian humanist author, artist, architect, poet, priest, linguist, philosopher and cryptographer Leon Battista Alberti is thought to have possibly projected painted pictures from a small closed box with a small hole, but it is unclear whether this actually was a projector or rather a type of show box with transparent pictures illuminated from behind and viewed through the hole.
[17] Leonardo da Vinci is thought to have had a projecting lantern - with a condensing lens, candle and chimney - based on a small sketch from around 1515.
[18] In his Three Books of Occult Philosophy (1531–1533) Heinrich Cornelius Agrippa claimed that it was possible to project "images artificially painted, or written letters" onto the surface of the Moon with the means of moonbeams and their "resemblances being multiplied in the air".
[19] In 1589 Giambattista della Porta published about the ancient art of projecting mirror writing in his book Magia Naturalis.
[23] The 1645 first edition of German Jesuit scholar Athanasius Kircher's book Ars Magna Lucis et Umbrae included a description of his invention, the steganographic mirror: a primitive projection system with a focusing lens and text or pictures painted on a concave mirror reflecting sunlight, mostly intended for long distance communication.
He saw limitations in the increase of size and diminished clarity over a long distance and expressed his hope that someone would find a method to improve on this.
By 1659 Dutch scientist Christiaan Huygens had developed the magic lantern, which used a concave mirror to reflect and direct as much of the light of a lamp as possible through a small sheet of glass on which was the image to be projected, and onward into a focusing lens at the front of the apparatus to project the image onto a wall or screen (Huygens apparatus actually used two additional lenses).
[30] In 1774 English instrument maker Benjamin Martin introduced his "Opake Solar Microscope" for the enlarged projection of opaque objects.
He claimed: The Opake Microsc[o]pe, not only magnifies the natural Appearance or Size of Objects of every Sort, but at the ſame time throws ſuch a Quantity of Solar Rays upon them, as to make all their Colours appear vaſtly more vivid and ſtrong than to the naked Eye; and their Parts ſo expanded and diſtinct upon a fixed Screen, that they are not only viewed with the utmoſt Pleaſure, but may be drawn with the greateſt Eaſe by any ingenious Hand.
"[31]The solar microscope,[32] was employed in experiments with photosensitive silver nitrate by Thomas Wedgwood in collaboration with Humphry Davy in making the first, but impermanent, photographic enlargements.
Their discoveries, regarded as the earliest deliberate and successful form of photography, were published in June 1802 by Davy in his An Account of a Method of Copying Paintings upon Glass, and of Making Profiles, by the Agency of Light upon Nitrate of Silver.
[33][34] Swiss mathematician, physicist, astronomer, logician and engineer Leonhard Euler demonstrated an opaque projector, now commonly known as an episcope, around 1756.
[36] Around 1872 Henry Morton used an opaque projector in demonstrations for huge audiences, for example in the Philadelphia Opera House which could seat 3500 people.
His machine did not use a condenser or reflector, but used an oxyhydrogen lamp close to the object in order to project huge clear images.
