Editing Camera obscura (section)

===1450 to 1600: Depiction, lenses, drawing aid, mirrors===
[[File:Da vinci - camera obscura (from notebooks 71) 0071-q75-644x596.jpg|thumb|Da Vinci: Let ''a b c d e'' be the object illuminated by the sun and ''o r'' the front of the dark chamber in which is the said hole at ''n m''. Let ''s t'' be the sheet of paper intercepting the rays of the images of these objects upside down, because the rays being straight, ''a'' on the right hand becomes ''k'' on the left, and ''e'' on the left becomes ''f'' on the right<ref>{{cite web|title=The Notebooks of Leonardo da Vinci|publisher=FromOldBooks.org|editor=[[Jean Paul Richter]]|year=1880|page=71|url=http://www.fromoldbooks.org/Richter-NotebooksOfLeonardo/section-2/item-71.html|access-date=24 September 2016|archive-date=24 September 2016|archive-url=https://web.archive.org/web/20160924192917/http://www.fromoldbooks.org/Richter-NotebooksOfLeonardo/section-2/item-71.html|url-status=live}}</ref>]]
Italian polymath [[Leonardo da Vinci]] (1452–1519), familiar with the work of Alhazen in Latin translation<ref>{{citation |first1= Ahmed H. |title= 4D Electron Microscopy: Imaging in Space and Time |date= 2010 |last1= Zewail |last2= Thomas |first2= John Meurig |publisher= World Scientific |isbn= 9781848163904|page=5}}: "The Latin translation of Alhazen's work influenced scientists and philosophers such as (Roger) Bacon and da Vinci, and formed the foundation for the work by mathematicians like Kepler, Descartes and Huygens..."</ref> and having extensively studied the physics and physiological aspects of optics, wrote the oldest known clear description of the ''camera obscura'', in 1502 (found in the ''[[Codex Atlanticus]]'', translated from Latin):

{{blockquote|If the facade of a building, or a place, or a landscape is illuminated by the sun and a small hole is drilled in the wall of a room in a building facing this, which is not directly lighted by the sun, then all objects illuminated by the sun will send their images through this aperture and will appear, upside down, on the wall facing the hole.
You will catch these pictures on a piece of white paper, which placed vertically in the room not far from that opening, and you will see all the above-mentioned objects on this paper in their natural shapes or colors, but they will appear smaller and upside down, on account of crossing of the rays at that aperture. If these pictures originate from a place which is illuminated by the sun, they will appear colored on the paper exactly as they are. The paper should be very thin and must be viewed from the back.<ref>Josef Maria Eder ''History of Photography'' translated by Edward Epstean Hon. F.R.P.S Copyright Columbia University Press</ref>}}

These descriptions, however, would remain unknown until Venturi deciphered and published them in 1797.<ref name=Repstad>{{cite web|url=https://jongrepstad.com/pinhole-photography/pinhole-photography-history-images-cameras-formulas/|title=Pinhole Photography – History, Images, Cameras, Formulas|first=Jon|last=Grepstad|date=20 October 2015|access-date=1 September 2016|archive-date=17 September 2016|archive-url=https://web.archive.org/web/20160917104024/https://jongrepstad.com/pinhole-photography/pinhole-photography-history-images-cameras-formulas/|url-status=live}}</ref>

Da Vinci was clearly very interested in the ''camera obscura'': over the years he drew approximately 270 diagrams of the ''camera obscura'' in his notebooks. He systematically experimented with various shapes and sizes of apertures and with multiple apertures (1, 2, 3, 4, 8, 16, 24, 28 and 32). He compared the working of the eye to that of the ''camera obscura'' and seemed especially interested in its capability of demonstrating basic principles of optics: the inversion of images through the pinhole or pupil, the non-interference of images and the fact that images are "all in all and all in every part".<ref>{{cite web |url=http://www.sumscorp.com/leonardo_studies/news_98.html |title=Leonardo and the Camera Obscura / Kim Veltman |publisher=Sumscorp.com |date=2 December 1986 |access-date=2 May 2017 |archive-date=18 September 2017 |archive-url=https://web.archive.org/web/20170918063919/http://www.sumscorp.com/leonardo_studies/news_98.html |url-status=dead }}</ref>

[[File:1545 gemma frisius - camera-obscura-sonnenfinsternis 1545-650x337.jpg|thumb|left|First published picture of ''camera obscura'', in Gemma Frisius' 1545 book ''De Radio Astronomica et Geometrica'']]
The oldest known published drawing of a ''camera obscura'' is found in Dutch physician, mathematician and instrument maker [[Gemma Frisius]]’ 1545 book ''De Radio Astronomica et Geometrica'', in which he described and illustrated how he used the ''camera obscura'' to study the solar eclipse of 24 January 1544<ref name=Repstad/>

Italian polymath [[Gerolamo Cardano]] described using a glass disc – probably a [[biconvex lens]] – in a ''camera obscura'' in his 1550 book ''De subtilitate, vol. I, Libri IV''. He suggested to use it to view "what takes place in the street when the sun shines" and advised to use a very white sheet of paper as a projection screen so the colours would not be dull.<ref name=Ilardi />

Sicilian mathematician and astronomer [[Francesco Maurolico]] (1494–1575) answered Aristotle's problem how sunlight that shines through rectangular holes can form round spots of light or crescent-shaped spots during an eclipse in his treatise ''Photismi de lumine et umbra'' (1521–1554). However this wasn't published before 1611,<ref>{{cite book|title=Photismi de lumine et umbra|year=1611|last=Maurolico|first=Francesco|url=https://books.google.com/books?id=Ug6ywn-D9BgC&pg=PP9|access-date=9 September 2017|archive-date=10 November 2023|archive-url=https://web.archive.org/web/20231110062244/https://books.google.com/books?id=Ug6ywn-D9BgC&pg=PP9#v=onepage&q&f=false|url-status=live}}</ref> after Johannes Kepler had published similar findings of his own.

Italian polymath [[Giambattista della Porta]] described the ''camera obscura'', which he called "''camera obscura''", in the 1558 first edition of his book series ''[[Magia Naturalis]]''. He suggested to use a convex lens to project the image onto paper and to use this as a drawing aid. Della Porta compared the human eye to the ''camera obscura'': "For the image is let into the eye through the eyeball just as here through the window". The popularity of Della Porta's books helped spread knowledge of the ''camera obscura''.<ref name=Larsen>{{cite web|url=http://www.williamshakespeare-sonnets.com/sonnet-24|last=Larsen|first=Kenneth|title=Sonnet 24|access-date=2 September 2016|archive-url=https://web.archive.org/web/20160707173823/http://www.williamshakespeare-sonnets.com/sonnet-24|archive-date=7 July 2016|url-status=dead}}</ref><ref>{{cite book|last=Durbin|first=P.T.|year=2012|title=Philosophy of Technology|page=74|publisher=Springer |url=https://books.google.com/books?id=R2OSBgAAQBAJ&pg=PA74|isbn=9789400923034|access-date=20 December 2019|archive-date=10 November 2023|archive-url=https://web.archive.org/web/20231110062244/https://books.google.com/books?id=R2OSBgAAQBAJ&pg=PA74#v=onepage&q&f=false|url-status=live}}</ref>

In his 1567 work ''La Pratica della Perspettiva'' Venetian nobleman [[Daniele Barbaro]] (1513-1570) described using a ''camera obscura'' with a biconvex lens as a drawing aid and points out that the picture is more vivid if the lens is covered as much as to leave a circumference in the middle.<ref name=Ilardi>{{cite book|title=Renaissance Vision from Spectacles to Telescopes|publisher=American Philosophical Society|last=Ilardi|first=Vincent|year=2007|url=https://archive.org/details/bub_gb_peIL7hVQUmwC|page=[https://archive.org/details/bub_gb_peIL7hVQUmwC/page/n231 220]|isbn=9780871692597}}</ref>

[[File:1646 Athanasius Kircher - Camera obscura.jpg|thumb|Illustration of "portable" ''camera obscura'' (similar to Risner's proposal) in Kircher's ''Ars Magna Lucis Et Umbrae'' (1645)]]
In his influential and meticulously annotated Latin edition of the works of Ibn al-Haytham and Witelo, {{lang|la|Opticae thesauru}} (1572), German mathematician [[Friedrich Risner]] proposed a portable ''camera obscura'' drawing aid; a lightweight wooden hut with lenses in each of its four walls that would project images of the surroundings on a paper cube in the middle. The construction could be carried on two wooden poles.<ref name=Snyder>{{cite book|title=Eye of the Beholder|last=Snyder|first=Laura J.|year=2015|publisher=W. W. Norton & Company|url=https://books.google.com/books?id=EQJ-BAAAQBAJ&q=friedrich+risner+camera+obscura&pg=PT110|isbn=9780393246520|access-date=9 November 2020|archive-date=10 November 2023|archive-url=https://web.archive.org/web/20231110062305/https://books.google.com/books?id=EQJ-BAAAQBAJ&q=friedrich+risner+camera+obscura&pg=PT110#v=snippet&q=friedrich%20risner%20camera%20obscura&f=false|url-status=live}}</ref> A very similar setup was illustrated in 1645 in [[Athanasius Kircher]]'s influential book ''Ars Magna Lucis Et Umbrae''.<ref>{{cite web |url=https://books.google.com/books?id=wYlDAAAAcAAJ&pg=PA806 |title=Ars Magna Lucis Et Umbrae |year=1645 |last=Kircher |first=Athanasius |language=la |page=806b |access-date=9 September 2017 |archive-date=10 November 2023 |archive-url=https://web.archive.org/web/20231110062300/https://books.google.com/books?id=wYlDAAAAcAAJ&pg=PA806#v=onepage&q&f=false |url-status=live }}</ref>

Around 1575 Italian Dominican priest, mathematician, astronomer, and cosmographer [[Ignazio Danti]] designed a ''camera obscura'' gnomon and a meridian line for the [[Basilica of Santa Maria Novella]], Florence, and he later had a massive gnomon built in the [[San Petronio Basilica]] in Bologna. The gnomon was used to study the movements of the Sun during the year and helped in determining the new Gregorian calendar for which Danti took place in the commission appointed by [[Pope Gregory XIII|Pope Gregorius XIII]] and instituted in 1582.<ref>{{cite web|last=Cassini|title=1655–2005: 350 Years of the Great Meridian Line|url=http://stelle.bo.astro.it/archivio/2005-anno-cassiniano/meridian_ing.htm|access-date=1 October 2016|archive-date=28 July 2016|archive-url=https://web.archive.org/web/20160728113319/http://stelle.bo.astro.it/archivio/2005-anno-cassiniano/meridian_ing.htm|url-status=live}}</ref>

In his 1585 book ''Diversarum Speculationum Mathematicarum''<ref>{{cite book|url=https://books.google.com/books?id=2CJFAAAAcAAJ&q=%22Diversarum%20Speculationum%20Mathematicarum%22&pg=PP1|title=Diversarum Speculationum Mathematicarum|last=Benedetti|first=Giambattista|year=1585|language=la|access-date=9 November 2020|archive-date=10 November 2023|archive-url=https://web.archive.org/web/20231110062301/https://books.google.com/books?id=2CJFAAAAcAAJ&q=%22Diversarum%20Speculationum%20Mathematicarum%22&pg=PP1#v=onepage&q=%22Diversarum%20Speculationum%20Mathematicarum%22&f=false|url-status=live}}</ref> Venetian mathematician [[Giambattista Benedetti]] proposed to use a mirror in a 45-degree angle to project the image upright. This leaves the image reversed, but would become common practice in later ''camera obscura'' boxes.<ref name=Ilardi />

Giambattista della Porta added a "lenticular crystal" or biconvex lens to the ''camera obscura'' description in the 1589 second edition of ''Magia Naturalis''. He also described use of the ''camera obscura'' to project hunting scenes, banquets, battles, plays, or anything desired on white sheets. Trees, forests, rivers, mountains "that are really so, or made by Art, of Wood, or some other matter" could be arranged on a plain in the sunshine on the other side of the ''camera obscura'' wall. Little children and animals (for instance handmade deer, wild boars, rhinos, elephants, and lions) could perform in this set. "Then, by degrees, they must appear, as coming out of their dens, upon the Plain: The Hunter he must come with his hunting Pole, Nets, Arrows, and other necessaries, that may represent hunting: Let there be Horns, Cornets, Trumpets sounded: those that are in the Chamber shall see Trees, Animals, Hunters Faces, and all the rest so plainly, that they cannot tell whether they be true or delusions: Swords drawn will glister in at the hole, that they will make people almost afraid." 
Della Porta claimed to have shown such spectacles often to his friends. They admired it very much and could hardly be convinced by della Porta's explanations that what they had seen was really an optical trick.<ref name=Larsen /><ref>{{cite book|url=https://quod.lib.umich.edu/e/eebo/A55484.0001.001/1:20?rgn=div1;view=fulltext|title=Natural Magick (Book XVII, Chap. V + VI)|author=Giovanni Battista della Porta|pages=363–365|year=1658|access-date=10 September 2018|archive-date=16 May 2020|archive-url=https://web.archive.org/web/20200516072234/https://quod.lib.umich.edu/e/eebo/A55484.0001.001/1:20?rgn=div1;view=fulltext|url-status=live}}</ref><ref>{{cite book|title=Magia Naturalis|year=1589|language=la|url=https://books.google.com/books?id=L2kjTEvXAdUC&pg=PT282|last1=Porta|first1=Giovan Battista Della|access-date=20 December 2019|archive-date=10 November 2023|archive-url=https://web.archive.org/web/20231110062248/https://books.google.com/books?id=L2kjTEvXAdUC&pg=PT282#v=onepage&q&f=false|url-status=live}}</ref>