WAYS:Light: Projection: In Space

5.a. An image or representation of an object formed on a surface (originally esp. the retina) from elsewhere; the action of forming such an image; (in later use) spec. the process of projecting an image on a film, slide, etc., on to a screen for viewing. Also fig.
1687   Philos. Trans. 1686–7 (Royal Soc.) 16 318   The Moon being nigh the Horizon and look'd at thro' a more foggy Air, casts a weaker Light,..and therefore the Pupil does more inlarge itself, thereby transmitting a larger Projection on the Retina.

The O.E.D. entry 5a for “projection” shows that projection (whether perceived by the eye or as part of the eye’s function) is dependent on the difference between a light source and the environment. The power and concentration of a light source relative to the ambient light, along with an ability to focus that light onto a specific area where difference of intensity and color are perceptible, is fundamental to any form of projection. That the shadows seen by the pre-historic cave-dweller produced a ‘protocinematic’ experience was stunningly shown in Werner Herzog’s 2011 film “Cave of Forgotten Dreams.”

Whenever fires and caves are mentioned Plato cannot be far behind, however, our understanding of projection as the result of a technical apparatus has its roots in the magic lantern. Credit for the invention of this seemingly simple device varies. Christiaan Huygens, known for advancing the theory that light travels as a wave and numerous other scientific achievements, came up with a projection lantern by November 1659. According to the Magic Lantern Society, by that date Huygens’ father was insistent that he be given one to “frighten his friends with”. Since their beginning, magic lanterns have been linked to the production of demonic images; this has carried into successive technologies in which phantoms, horror, and terror are commonplace.