View source for Camera lucida

{{Short description|Optical drawing aid}}
{{for|the 1980 book by Roland Barthes|Camera Lucida (book)}}
{{italic title}}
{{use mdy dates|date=April 2023}}
[[File:Camera Lucida in use drawing small figurine.jpg|thumb|Camera lucida in use]]
A '''''camera lucida''''' is an [[optical device]] used as a drawing aid by [[artist]]s and [[microscopy|microscopists]]. By looking through the [[prism]] in its standard, a user sees an [[optics|optical]] superimposition of the subject positioned in front of the device over the surface below. This allows the artist to duplicate key points of the scene on the drawing surface, thus aiding in the accurate rendering of perspective.

==History==

The ''camera lucida'' was patented in 1806 by the English chemist [[William Hyde Wollaston]].<ref>{{Cite book |last=Marien |first=Mary Warner |url=https://archive.org/details/photographycultu0000mari_d6n5/page/6/ |title=Photography: A Cultural History |date=2015 |publisher=[[Pearson Education]] |isbn=978-0-205-98894-5 |edition=4th |pages=6–7 |access-date=April 10, 2022}}</ref><ref>{{Cite book |last=Wollaston |first=William H. |url=https://archive.org/details/s2id13415980/page/343 |title=Description of the Camera Lucida |date=1807 |work=[[Philosophical Magazine|The Philosophical Magazine]] |pages=343–347 |author-link=William Hyde Wollaston |access-date=10 April 2022 |issue=27}}</ref>
<ref>{{Cite book |last=Pritchard, Andrew |url=https://trove.nla.gov.au/work/28403006 |title=English patents: being a register of all those granted for inventions in the arts, manufactures, chemistry, agriculture, etc., etc., during the first forty-five years of the present century |date=1847 |publisher=Whittaker and Co |quote=[[William Hyde Wollaston|Wollaston, William H.]] 'An Instrument Whereby Any Person May Draw in Perspective, or May Copy of Reduce Any Print or Drawing.' British Patent no. 2993 |access-date=September 10, 2019 |archive-date=October 25, 2022 |archive-url=https://web.archive.org/web/20221025191524/https://trove.nla.gov.au/work/28403006 |url-status=live }}</ref>

The basic optics were described 200 years earlier by the German astronomer [[Johannes Kepler]] in his ''Dioptrice'' (1611), but there is no evidence he constructed a working ''camera lucida''.<ref name=":0">{{Cite book |last1=Hammond |first1=John |title=The camera lucida in art and science |last2=Austin |first2=Jill |publisher=Taylor & Francis |year=1987 |location=Bristol |pages=ix, 113–172}}</ref> There is also evidence to suggest that the Elizabethan spy Arthur Gregory's 1596 "perspective box" operated on at least highly similar principles to the later ''camera lucida'', but the secretive nature of his work and fear of rivals copying his methods led to his invention becoming lost.<ref name=":v">{{Cite book |last1=Akkerman |last2=Longman |first1=Nadine |first2=Pete |title=Spycraft: Tricks and Tools of the Dangerous Trade from Elizabeth I to the Restoration |publisher=Yale University Press |year=2024 |location=New Haven and London |pages=186-187}}</ref> By the 19th century, Kepler's description had similarly fallen into oblivion, so Wollaston's claim to have invented the device was never challenged. The term "{{lang|la|camera lucida}}" ([[Latin]] 'well-lit room' as opposed to {{lang|la|[[camera obscura]]}} 'dark room') is Wollaston's.<ref>cf. {{Cite book |last=Hoppe |first=Edmund |url=https://books.google.com/books?id=qDUhQGk3I28C |title=Geschichte der Optik |year=1926 |isbn=9783846014219 |location=Leipzig |language=de |access-date=April 26, 2023 |archive-date=April 26, 2023 |archive-url=https://web.archive.org/web/20230426200035/https://books.google.com/books?id=qDUhQGk3I28C |url-status=live }}</ref>

While on honeymoon in Italy in 1833, the photographic pioneer [[William Fox Talbot]] used a ''camera lucida'' as a sketching aid. He later wrote that it was a disappointment with his resulting efforts which encouraged him to seek a means to "cause these natural images to imprint themselves durably".

In 2001, artist [[David Hockney]]'s book ''Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters'' was met with controversy. His argument, known as the [[Hockney-Falco thesis]], is that the notable transition in style for greater precision and visual realism that occurred around the decade of the 1420s is attributable to the artists' discovery of the capability of optical projection devices, specifically an arrangement using a [[concave mirror]] to project [[real image]]s. Hockney was inspired after seeing drawings by [[Jean Auguste Dominique Ingres|Ingres]], which he came to suspect were made with the aid of a camera lucida.

The ''camera lucida'' is still available today through art-supply channels but is not well known or widely used. It has enjoyed a resurgence as of 2017 through a number of Kickstarter campaigns.<ref>{{Cite web |title=NeoLucida |url=https://www.kickstarter.com/projects/neolucida/neolucida-a-portable-camera-lucida-for-the-21st-ce |website=Kickstarter |access-date=January 10, 2016 |archive-date=September 18, 2022 |archive-url=https://web.archive.org/web/20220918170529/https://www.kickstarter.com/projects/neolucida/neolucida-a-portable-camera-lucida-for-the-21st-ce |url-status=live }}</ref>

==Description==
[[File:cameralucidadiagram.png|thumb|Optics of [[William Hyde Wollaston|Wollaston]]'s ''camera lucida'']]
The name "{{lang|la|camera lucida}}" (Latin for 'light chamber') is intended to recall the much older drawing aid, the {{lang|la|[[camera obscura]]}} (Latin for 'dark chamber'). There is no optical similarity between the devices. The ''camera lucida'' is a lightweight, portable device that does not require special lighting conditions. No image is projected by the ''camera lucida''.{{citation needed|date=April 2023}}

In the simplest form of ''camera lucida'', the artist looks down at the drawing surface through a glass pane or half-silvered [[mirror]] tilted at 45 degrees. This superimposes a direct view of the drawing surface beneath, and a [[reflection (physics)|reflected]] view of a scene horizontally in front of the artist. This design produces an inverted image which is right-left reversed when turned the right way up. Also, light is lost in the imperfect reflection.{{citation needed|date=April 2023}}

Wollaston's design used a prism with four optical faces to produce two successive reflections (see illustration), thus producing an image that is not inverted or reversed. Angles ABC and ADC are 67.5° and BCD is 135°. Hence, the reflections occur through [[total internal reflection]], so very little light is lost. It is not possible to see straight through the prism, so it is necessary to look at the very edge to see the paper.<ref name="hockney-2006">{{Cite book |last=Hockney |first=David |title=Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters |publisher=Thames and Hudson |year=2006 |isbn=9780500286388}}
quote  {{cite book
 | last= Wollaston
 | first= W. H.
 | title= Description of the camera lucida
 | work= A Journal of Natural Philosophy, Chemistry, and the Arts
 | year= 1807
 | publisher= William Nicholson
 | url= https://books.google.com/books?id=AeA3AQAAIAAJ&dq=Wollaston,+W.+H.+(1807).+%22Description+of+the+camera+lucida%22.+A+Journal+of+Natural+Philosophy,+Chemistry,+and+the+Arts&pg=PR4
 | access-date= April 26, 2023
 | archive-date= April 26, 2023
 | archive-url= https://web.archive.org/web/20230426200035/https://books.google.com/books?id=AeA3AQAAIAAJ&dq=Wollaston,+W.+H.+(1807).+%22Description+of+the+camera+lucida%22.+A+Journal+of+Natural+Philosophy,+Chemistry,+and+the+Arts&pg=PR4
 | url-status= live
 }}</ref>

The instrument often came with an assortment of weak negative lenses, to create a [[virtual image]] of the scene at several distances. If the right lens is inserted, so that the chosen distance roughly equals the distance of the drawing surface, both images can be viewed in good [[focus (optics)|focus]] simultaneously.{{citation needed|date=April 2023}}

If white paper is used with the ''camera lucida'', the superimposition of the paper with the scene tends to wash out the scene, making it difficult to view. When working with a ''camera lucida'', it is often beneficial to use toned or grey paper. Some historical designs included shaded filters to help balance lighting. {{citation needed|date=April 2023}}

==Microscopy==
As recently as the 1980s, the ''camera lucida'' was still a standard tool of [[microscope|microscopists]].<ref name=":0" />  It is still a key tool in the field of palaeontology. Until very recently, [[photomicrograph]]s were expensive to reproduce. Furthermore, in many cases, a clear illustration of the structure that the microscopist wished to document was much easier to produce by drawing than by micrography. Thus, most routine histological and microanatomical illustrations in textbooks and research papers were ''camera lucida'' drawings rather than photomicrographs. The ''camera lucida'' is still used as the most common method among neurobiologists for drawing brain structures, although it is recognised to have limitations. "For decades in cellular neuroscience, camera lucida hand drawings have constituted essential illustrations. (...) The limitations of camera lucida can be avoided by the procedure of digital reconstruction".<ref>{{Cite journal |last=Giorgio A. Ascoli |url=https://www.nature.com/articles/nrn1885 |title=Mobilizing the base of neuroscience data: the case of neuronal morphologies |date=April 2006 |journal=Nature Reviews. Neuroscience |volume=7 |page=319 |doi=10.1038/nrn1885 |pmid=16552417 |issue=4 |s2cid=7953115 |access-date=April 26, 2023 |archive-date=May 3, 2023 |archive-url=https://web.archive.org/web/20230503152810/https://www.nature.com/articles/nrn1885 |url-status=live |url-access=subscription }}</ref> Of particular concern is distortion, and new digital methods are being introduced which can limit or remove this, "computerized techniques result in far fewer errors in data transcription and analysis than the camera lucida procedure".<ref>{{Cite journal |last=T.J. DeVoogd |url=https://pubmed.ncbi.nlm.nih.gov/6163933 |title=Distortions induced in neuronal quantification by camera lucida analysis: Comparisons using a semi-automated data acquisition system |date=February 1981 |journal=Journal of Neuroscience Methods |others=et al |volume=3 |pages=285–294 |doi=10.1016/0165-0270(81)90064-9 |pmid=6163933 |issue=3 |s2cid=31921940 |access-date=April 26, 2023 |archive-date=May 2, 2023 |archive-url=https://web.archive.org/web/20230502223627/https://pubmed.ncbi.nlm.nih.gov/6163933/ |url-status=live }}</ref> It is also regularly used in [[biological taxonomy]].

==Gallery==
{{wide image|Mr Jenkins cottage, Illawarra, John Rae.jpg|1150px|Scenery from Mr Jenkins' cottage, [[Illawarra]], ca. 1850, by John Rae, watercolour drawing created using a ''camera lucida'', State Library of New South Wales, DL PXX 74 no.16}}

==See also==
*[[Camera obscura]]
*[[Claude Glass|Claude glass, or black mirror]]
*[[Graphic telescope]]
*[[Pepper's ghost]]

==References==
{{reflist}}

==External links==
{{Commons category}}
*[http://physics.kenyon.edu/EarlyApparatus/Optics/Camera_Lucida/Camera_Lucida.html Kenyon College Department of Physics on the ''Camera Lucida'']
*{{cite EB1911|wstitle=Camera Lucida|volume=5}}

{{Mathematics and art}}
{{Authority control}}

[[Category:Artistic techniques]]
[[Category:Optical devices]]
[[Category:Precursors of photography]]
[[Category:Drawing aids]]