David Hockney can be credited with bringing the camera lucida to the attention of the world in the 21st century. The front cover of his bestselling book, 'Secret Knowledge', shows him at work using the instrument.

The camera obscura is remembered — possibly due to the fact that many people will have encountered these installations whilst on holiday. But the camera lucida? The nineteenth century device, small, portable — able to fold up into a case that could be slipped into a large pocket? No. It had largely been forgotten — known only to the collectors of antique optical instruments.

Hockney was interested in whether or not the artist, Ingres used the instrument. Did he or did he not? Almost certainly — but in the grand scheme of things, it doesn’t really matter.

What is of greater interest is the known users of the camera lucida who were keen to exploit the potential of the instrument and made no secret of its use. After William Wollaston patented has camera lucida design in 1807, its potential was quickly exploited. Over time his design was refined and the camera lucida became easy to use.

It had numerous applications. The camera lucida was employed by the sculptor Francis Chantrey, keen to obtain a quick and exact likeness of his subjects, by travellers such as Wiliam Bartlet who wanted to share with the public their accurate drawing of lands that were previously represented in a romantic idealised form, and by the medical profession who could obtain detailed scientific drawings of the body. Geologists used camera lucidas, which were easily transported, to produce accurate drawings as did archaeologists who could record their finds exactly as they had discovered them.

It was particularly important in producing topographical drawings of America and employed by the controversial writer, Captain Basil Hall who published 'Forty Etchings of America' which allowed the British and American public a view of a diverse range of subjects which included slavery. The American Exploring Expedition employed a team of artists equipped with camera lucida to produce images from around the Southern hemisphere. Their Anthropological drawings of Fijian chiefs and native American Indians have survived – along with snapshots of the ships’ crews.

Some of the most beautiful camera lucida drawings still in existence were produced by Frederick Catherwood who stumbled upon the remains of the Mayan civilization buried deep in the jungles of Central America. His detailed drawings of the Mayan monuments are well worth looking up on Google. He was accompanied by the writer, George Stephens and their tale of hacking through the dense undergrowth and discovering a series of abandoned cities has inspired generation of writers of 'boys own' fiction. Had there been no camera lucida, there may well have been no Indiana Jones!