The camera lucida, invented by William Hyde Wollaston in 1807, was a drawing aid and therefor not photographic. It did though give impetus, along with the camera obscura, to the search for a way of permanently recording images direct from nature.

In contrast to the obscura, the lucida does not produce a real image of the subject. The instrument is clamped to the drawing board facing the subject, the user looks down at the top edge of the instrument where part of the eye will see an image reflected by the camera lucida and part will see the drawing paper direct.¹ For the two images to appear co-incident the subject distance should be the same as the distance to the drawing, if this is not the case lenses can be introduced below the instrument to alter the image of the drawing paper, lenses can also be fixed in front of the prism.

The prism is four sided with one internal angle of 90°, another of 135°, the other two angles are equal. The subject is internally reflected by the two obtuse faces.

Simpler instruments using a semi-silvered mirror were commonly provided as microscope accessories and were also known as a camera lucida.