Darkroom (camera obscura) or optic camera. More or less complex optical apparatus which in its fundamental components appears to be constituted by a box equipped with a hole and a lens (usually a frosted glass) through which the light is reflected on a screen placed on the internal bottom and opposite the hole.
By adjusting the distance between the lens and the screen, the darkroom allows you to project the image captured by the lens, even if it is upside down and reversed.
The darkroom, or camera obscura, already described by some Arabian astronomers of the Ninth Century, allowed the painter to copy onto a two-dimensional surface the complexity of a three-dimensional space and also provided an effective control of lights and shadows. In the dark rooms with an internal observer, the painter, from within the machine, could retrace the subject that was projected directly onto the sheet of paper. In the case of reflex cameras, use is mediated by the use of a sheet of tracing paper.
French: Chambre noire – Italian: Camera oscura– Spanish: Càmara oscura – German: Camera obscura.