Lecture notes on Camera Lucida and its importance.

A camera lucida is an optical device used for drawing the diagram of microscopic objects . It was invented in 1806 by William Hyde Wollaston and Christian Gobrecht

  The term"camera lucida" means "lit room" in Latin. The camera lucida performs an optical

superimposition of the subject being viewed and the surface on which the

observer is drawing . The person sees both the image of the specimen

and drawing surface simultaneously, as in a photographic double exposure, This

allows the person to trace the outlines of the image using a pencil. If white paper

is used, the superimposition of the paper with the scene tends to wash out the

scene, making it difficult to view. Camera lucida works on simple optical principle reflecting beam of light through a prism and a plane mirror.

The microscopic image of the object is reflected by the prism on to the plane mirror and there from the image is reflected on to the plane white paper. The person who observe moves the pencil on the lines of the image and draws a correct and faithful figure of the object on the paper.

When working with a camera lucida it is beneficial to use black paper and to draw with a white pencil.Camera lucida sketches are often used to supplement photomicrographs to make clear illustration of a structure. In many cases, drawings on camera lucida may provide more clarity and comprehension than photomicrographs. Thus,histological and microanatomical illustrations in textbooks and research papers are often camera lucida drawings rather than photomicrographs.