What is "camera lucida"

Camera lucida \Cam"e*ra lu"ci*da\ [L. camera chamber + L. lucidus, lucida, lucid, light.] (Opt.) An instrument which by means of a prism of a peculiar form, or an arrangement of mirrors, causes an apparent image of an external object or objects to appear as if projected upon a plane surface, as of paper or canvas, so that the outlines may conveniently traced. It is generally used with the microscope. [1913 Webster] ||

n. An instrument that uses a shaped prism or mirrors to cause an apparent image of external objects to appear as if projected upon a plane surface, so that the outlines may be conveniently traced.

n. an optical device consisting of an attachment that enables an observer to view simultaneously the image and a drawing surface for sketching it

A camera lucida is an optical device used as a drawing aid by artists.

The camera lucida performs an optical superimposition of the subject being viewed upon the surface upon which the artist is drawing. The artist sees both scene and drawing surface simultaneously, as in a photographic double exposure. This allows the artist to duplicate key points of the scene on the drawing surface, thus aiding in the accurate rendering of perspective.

Camera Lucida is a short book published in 1980 by the French literary theorist and philosopher Roland Barthes. It is simultaneously an inquiry into the nature and essence of photography and a eulogy to Barthes' late mother. The book investigates the effects of photography on the spectator (as distinct from the photographer, and also from the object photographed, which Barthes calls the "spectrum").

In a deeply personal discussion of the lasting emotional effect of certain photographs, Barthes considers photography as asymbolic, irreducible to the codes of language or culture, acting on the body as much as on the mind. The book develops the twin concepts of studium and punctum: studium denoting the cultural, linguistic, and political interpretation of a photograph, punctum denoting the wounding, personally touching detail which establishes a direct relationship with the object or person within it.