Talk:Camera obscura

message: :Having gone over some books and sources over the Internet, it is important we mention Mo-Ti's and Aristotle's discovery of the camera oscura principle first, which dates prior to Al-Hasan's assembly of the princicples. This will help this article become more factual, detailed and useful to Wikipedia users. I will soon provide some links and ISBNs for sources we could use to accurately describe the discovery and creation with fair credits to the concerned people. Here is an extract:
:"The earliest mention of this type of device was by the Chinese philosopher Mo-Ti (5th century BC). He formally recorded the creation of an inverted image formed by light rays passing through a pinhole into a darkened room. He called this darkened room a "collecting place" or the "locked treasure room."
:Aristotle (384-322 BC) understood the optical principle of the camera obscura. He viewed the crescent shape of a partially eclipsed sun projected on the ground through the holes in a sieve, and the gaps between leaves of a plane tree.
:The Islamic scholar and scientist Alhazen (Abu Ali al-Hasan Ibn al-Haitham) (c.965 - 1039) gave a full account of the principle including experiments with five lanterns outside a room with a small hole. "
::link http://brightbytes.com/cosite/what.html
:If I don't hear from anyone who is willing to collaborate, I will run through with you guys the proposed addition and then proceed to add the amendments myself. --Sina7 (Signature added by Downtownee)
::Please do. My previous note concerned this matter. I'm delighted someone is going to take it over. I put my note before yours for the sake of being chronologically ordered while having related notes together. -- Downtownee 07:53, 3 October 2007 (UTC)
thread_title:  The invention/creation of the Camera Oscura 

message: I believe there is one in seville, spain that gives a view of most of the city and all of the expo '92, it is called, "torre tavira". I don't dare edit the article but if anyone can verify then it should be added to the list of locations. 65.184.41.200 02:59, 3 October 2007 (UTC)
thread_title:  Seville 

message: Since the correct italian spelling is Camera oscura (without b), I'd redirect it to the correct spelling, unless in english it is used instead with the current spelling. In this case I'd add a redirect from Camera oscura. --Gianfranco
"Camera obscura" is correct in English. It's Latin, not Italian. --Zundark, Tuesday, April 9, 2002
:Just a note: English is Germanic. Italian, is, a Latin language. --Downtownee 10:29, 4 February 2007 (UTC)
thread_title:  Latin word 

message: Wasn't there some consperacy theory that the old masters used these to make their paintings?
: Yes, see David Hockney. It needs adding to this article. Justinc 22:28, 8 Apr 2005 (UTC)
replies: text: Yes there were. It is not considered a conspiracy though. One of the first uses of the new invention, photgraphy, esp. during 1850s, was its assistance to painters. There were a debate on if photography is indeed a distict form of art, and many of the first photogrpahers were either painters themselves or were commissioned to make up very complicated images used by painting masters as "sketches". One of these photographers was O. G. Rejlander. Also have a look at Henry P. Robinson, who held a view of the photography must follow aesthetic and scenery rules of the contemporary painting. Plus Hockney is not an "old" master! --Downtownee 10:29, 4 February 2007 (UTC)
thread_title:  Old painting masters 

message: The article says there is considerable controversy over whether Vermeer and others used the camera obscura. But last night I saw a documentary on the BBC (Light Fantastic) where it was said that a precise date can be given when Vermeer switched fully to the camera obscura. Now there were some inaccuracies in the documentary but those were simplifications for 'the less educated viewer', so to say. But saying one can pinpoint a date is something different. Anyone know more? DirkvdM 06:28, 25 August 2005 (UTC)
replies: text: Rebecca Stefoff in The Cameranotes Philip Steadman's detailed analysis and reconstruction of Vermeer's use of the camera obscura and that though some art historians still dispute his proofs, it is certain that Canaletto was admired for his skill in judiciously employing the device, and that there is no doubt that Joshua Reynolds made use of his, which was disguised as a book, despite his deprecation of it as an instrument of 'high art' in his' Discourses on painting and the fine arts : delivered at the Royal Academy ~~~~
== Resolution ==
The article said that a pinhole gives low resolution, which can be solved by using a lens. I don't see how this influences resolution (it does influence light-sensitivity, though), so I removed that. Resolution is a matter of how fine the grain is in a photocamera. The equivalent in the camera obscura would be how accurate the artist is, I suppose. DirkvdM 06:58, 25 August 2005 (UTC)

text: A formula can be found at pinhole camera#Selection of pinhole size. Anyway, a pinhole for this use gives neither brightness nor resolution. Meggar 03:12, 11 January 2006 (UTC)
replies: text: resolution is not just a term relevant to film grain. it refers to how well an image resolves at the VP. If you've ever tried making a pinhole camera, and have used a huge hole, you will know that the circle of confusion becomes so great that the image is comprised of large circles, it is then said to have poor resolution. DavidP
== removed this etymology ==
 also known in Arabic as “qamara”, hence Latin camera
Since it isn't - "camera" is Latin for "chamber", and was long before the invention of the camera obscura. (See  for example) FiggyBee 09:22, 13 November 2006 (UTC)

text: Muslim community, especially in Middle East as its origin, is intentionally and, through elementary education, unconsciously aware of a brotherhood among themselves called "umma." Hence many Muslims are used to indicate or show interest if someone is of their own religion. Your point, nevertheless, is right and it should be asked to be tolerated by Muslims if these kind of remarks are removed from the text. Downtownee 12:27, 11 May 2007 (UTC)

text: Not really. Every biography of Ibn al-Haytham clearly states that he was born in Basra and later worked in Cairo. Jagged 85 (talk) 09:46, 18 July 2008 (UTC)

text: What Mozi and Aristotle described were the principles of a pinhole camera. What Ibn al-Haytham described was a camera obscura ("dark chamber"). Jagged 85 (talk) 22:15, 3 February 2008 (UTC)
replies: text: Jagged 85 clearly has an agenda here or knows nothing about photography. More to the point it's pretty gross you keep using the term "iraqi". I don't refer to Native American tribes which ones existed in the USA as "New Jerseyian". Since you're paying more attention to the wording "iraqi" then you are interested in reconciling the technological differences between the observations Aristotle made and Mozi I'm going to call you on bullshit.  —Preceding unsigned comment added by 12.150.11.25 (talk) 21:22, 11 June 2008 (UTC)
replies: text: Dude, I'm not the one who wrote this article. If you just came here to personally attack me, go to my talk page and do it. Anyway, I've recently updated the article to include all the different versions of the camera obscura, from the rudimentary version described by Aristotle to the complete modern version described by Alhazen. Jagged 85 (talk) 09:43, 18 July 2008 (UTC)

text: While these earlier scholars described the effects of a single light passing through a pinhole, none of them suggested that what is being projected onto the screen is an image of everything on the other side of the aperture. Abu Ali Al-Hasan Ibn al-Haytham (965–1039 AD), known in the West as Alhacen or Alhazen, in his Book of Optics (1021), was the first to demonstrate this with his lamp experiment where several different light sources are arranged across a large area, and he was thus the first scientist to successfully project an entire image from outdoors onto a screen indoors with the camera obscura.<ref name=Steffens>
Bradley Steffens (2006), 
Ibn al-Haytham: First Scientist, 
Chapter Five, Morgan Reynolds Publishing, 
David Hockney, (2001, 2006) in Secret Knowledge: rediscovering the lost techniques of the old masters  (expanded edition) cites Alhazen several times as the likely source for the portraiture technique using the camera obscura, which Hockney rediscovered. Kitab al-Manazir, which is Alhazen's Book of Optics at that time denoted Opticae Thesaurus, Alhazen Arabis, was translated from Arabic into Latin for European use as early as 1270. Hockney cites Friedrich Risner's 1572 Basle edition of Opticae Thesaurus. Hockney quotes Alhazen as the first clear description of the camera obscura in Hockney, p. 240.
Alhazen provided the first clear description and correct analysis of the device and for first describing how an image is formed in the eye using the camera obscura as an analogy.
David H. Kelley, Exploring Ancient Skies: An Encyclopedic Survey of Archaeoastronomy: 
"The first clear description of the device appears in the Book of Optics of Alhazen."
 : "The principles of the camera obscura first began to be correctly analysed in the eleventh century, when they were outlined by Ibn al-Haytham."
 
Gul A. Russell, "Emergence of Physiological Optics", pp. 689 & 695-8, in
 
The assertion that "none of them suggested that what is being projected onto the screen is an image of everything on the other side of the aperture" is quite unbeleiveable in the light of "The Greek philosopher Aristotle (384 to 322 BCE) understood the optical principle of the pinhole camera. He viewed the crescent shape of a partially eclipsed sun projected on the ground through the holes in a sieve, and the gaps between leaves of a plane tree". I suspect (but haven't verified) that this is yet more Jaggedese William M. Connolley (talk) 10:04, 23 March 2011 (UTC)
thread_title:  Vermeer 

message: As it currently stands, all mention of Alhazen has been eliminated from the article, except for a couple reference titles. If the article had once been too laudatory of Alhazen's contributions, it is now at the other extreme. Others provide evidence below that Alhazen's use of the camera obscura is a milestone in the history of science. The sentence, "The Song Dynasty Chinese scientist Shen Kuo (1031–1095) experimented with a camera obscura, and was the first to apply geometrical and quantitative attributes to it in his book of 1088 AD, the Dream Pool Essays" is false. Alhazen's Book of Optics is from 1021. I also suggest you use the latinized "Alhazen" in the article (and the talk) as that is how is referred to in his Wikipedia article.  — Preceding unsigned comment added by McLir (talk • contribs) 13:40, 22 February 2012 (UTC)
replies: text: Perhaps that's partly my fault.  In this edit I took out an unsourced bit about Alhazen that had been stuck in at a bad place, with no support.  I'm certainly not against getting a good correct sourced history in there.  Maybe you can work on that.  Dicklyon (talk) 23:27, 22 February 2012 (UTC)
thread_title:  Alhazen is Missing 

message: There is an article about camera obscura on Chinese wiki, please also add it, thanks.
http://zh.wikipedia.org/wiki/%E6%9A%97%E7%AE%B1  — Preceding unsigned comment added by 112.118.41.91 (talk) 07:02, 23 November 2013 (UTC)
thread_title:  Other languages 

message: (I didn't have a pen handy while watching the 5th episode of "Cosmos: A Spacetime Odyssey", "Hiding in the Light", but I believe the man's name might have been given as "Mo Tze" in the animation.) Anyway, some information about his his life and beliefs was presented in a very positive light. He was credited with developing the beginnings of the scientific method and demonstrating the camera obscura. The segment about Al-Hazen is even longer and of course the camera obscrura is discussed. I think he was referred to Arabic. If you missed this episode, it's being rebroadcast on the "National Geographic Channel" at 11P eastern tonight (right now!). Or you can watch the episode on the show's website for the next 97 days. http://www.cosmosontv.com/ Yours, Wordreader (talk) 03:01, 8 April 2014 (UTC)
thread_title:  Mo Tze and Al-Hazen mentioned on Cosmos regarding the camera obscrura 

message: Article text: The Greek philosopher Aristotle (384 to 322 BCE) understood the optical principle of the pinhole camera.[3] He viewed the crescent shape of a partially eclipsed sun projected on the ground through the holes in a sieve and through the gaps between the leaves of a plane tree. In the 4th century BCE, Aristotle noted that "sunlight travelling through small openings between the leaves of a tree, the holes of a sieve, the openings wickerwork, and even interlaced fingers will create circular patches of light on the ground."
Correct quote: (many places on the net):
"Why is it that when the sun passes through quadri-laterals, as for instance in wickerwork, it does not produce a figure rectangular in shape but circular?" he wrote. "Why is it that an eclipse of the sun, if one looks at it through a sieve or through leaves, such as a plane-tree or other broadleaved tree, or if one joins the fingers of one hand over the fingers of the other, the rays are crescent-shaped where they reach the earth?"
For the answer suggested, see:    http://science.nasa.gov/science-news/science-at-nasa/2003/30may_solareclipse2/    RPSM (talk) 10:25, 18 September 2014 (UTC)
replies: text: The holes in the wickerwork or sieve are the pinholes, each forming an image. The wording "... if one looks at it through ..." is suggestive of some other phenomenon, but the statement that "the rays are crescent-shaped where they reach the earth" makes it clear that projected images are the subject, not direct viewing through the apertures. My guess is that the original Greek for what is here rendered as "through" might more accurately be translated as "by means of" or the like. Being a NASA scientist is no guarantee of expertise in the nuances of ancient Greek. Diffraction would have played no essential role in forming the projected images described. 66.81.241.184 (talk) 02:57, 12 June 2016 (UTC)

text: To clarify my previous comment: the role of diffraction in forming a pinhole image is of negligible importance unless the pinhole is small enough that edge diffraction affects a significant percentage of the light passing through it. With a relatively large hole (as in an ancient sieve), the imaging can be explained solely by the fact that rays from the subject travel in straight lines (because they are not diffracted) from the subject through the hole and onto the projection surface. Aristotle's question can be answered without recourse to the phenomenon of diffraction: an image of the solar disk formed through a square hole will only appear round if the image of the Sun is sufficiently large in comparison to the correspondingly distant hole. Each point of the Sun is actually imaged as a square, but the size of each such square is constant regardless of the projection distance, while the image of the Sun as a whole becomes larger with increased distance. In other words, the image seen actually consists of numberless images of the square hole (or a square array of overlapping images of the Sun's disk, if you prefer) which are not individually discernible. But the image will be quite noticeably square if the projection surface is very near the same square hole and the image formed is therefore very small. 66.81.241.184 (talk) 04:13, 12 June 2016 (UTC)
thread_title:  Aristotle is misquoted - and according to a reliable source (NASA) he was not referring to the pinhole camera, but to the phenomenon of diffraction 

message: I took out the assertion that Alhazen‎ invented the camera obscura. That turns out to be User:Jagged 85 , and hence unreliable William M. Connolley (talk) 21:13, 4 January 2015 (UTC)
replies: text:  Hmm. The artcile could use some Brünofication still. Serten II (talk) 21:32, 6 January 2015 (UTC)
thread_title:  Invented 

message: The camera obscura on Constitution Hill in Aberystwyth is open to the general public from 11 am to 4 pm every day. One of the largest in the world, it was built in 1880. Everybody got to be somewhere! (talk) 15:01, 22 May 2016 (UTC)
thread_title:  Aberystwyth 

message: * Pinhole camera
* Camera obscura
* Solar_eclipse#Viewing
* Pinhole (optics)
* Pinhole camera model (Redirected from Pinhole projection)
* Magic lantern
Some readers come to WP seeking info about direct viewing of pinhole projected image, such as for eclipses. There are many related WP articles, perhaps most relevant Pinhole camera, but none that do a great job of discussing the subject. (Also, a good discussion might mention that with care and fiddling ordinary hand-held binoculars can do quite a good job of projecting a clear and sizable image onto a safe surface.)-71.174.177.142 (talk) 21:46, 21 August 2017 (UTC)
thread_title:  pinhole image projection direct viewing 

message: Back in 2016, in this edit, we took to equating "pinhole images" to the camera obscura.  And before that it was already a "phenomenon".  All the books I can find say that a camera obscura is the "dark room" in which the image is formed; the structure or apparatus, not the phenomenon, and not the image.  Comments before I work on rewriting the lead accordingly? Dicklyon (talk) 22:26, 15 October 2020 (UTC)
replies: text: I only noticed this question today. I believe it was problematic that the term "pinhole images" was removed from the lead, because its oft-repeated use in the rest of the text made much less sense without it. I hope my new addition to the text helps. Unfortunately, I have not yet found sources that are more useful (amongst all the clutter about photographic pinhole images and some other technical applications). There must be some citation-worthy texts that properly describe this physical phenomenon, but I gave up looking. From the refs that I did include, it must nonetheless be clear enough that "pinhole image" is the same as the principle of "camera obscura" and that these terms do get equated.Joortje1 (talk) 21:36, 16 September 2023 (UTC)
thread_title:  Pinhole images? 

message: This article repeatedly asserts that such-and-such a person (eg Roger Bacon) “falsely” argued for a particular proposition. Unless it is being suggested that the person deliberately argued a case that he knew to be wrong (in which case the assertion should be properly evidenced), the adverb “falsely” constitutes a misuse of the English language. It may be that the author is not a native English speaker, but a better choice would be “mistakenly” or “incorrectly”. Teagueqc (talk) 14:53, 28 March 2024 (UTC)
thread_title:  Use of language