Talk:Perspective distortion
A close up portrait shot with a, say 24 or 28 mm, compared to a portrait of the same person using a 105 is in my opinon the best example of perspective distortion -- all assuming a 35 mm camera ;-). -- Egil 18:52 Jan 29, 2003 (UTC)
nice addition, Egil. could you explain about "pillow" distortion? I've never heard of it. And, yes, it is a 35mm camera. I'll try the portraits when I next get a chance (probably in late february!) That amateur photographer, Koyaanis Qatsi
- It is usually called cushion, mea culpa. A perfect wide angle shall never produce curved lines. But even the best of extreme wide angle lenses always produce curved lines to a certain degree, esp. close to the image boundaries. So if you take a picture of a rectangle, it ends up looking like a cushion. A fish-eye is a lens where they have given up correcting this completely. See Aberration in optical systems.-- Egil 19:14 Jan 29, 2003 (UTC)
- Right, I knew about the fisheyes. For 35mm cameras, doesn't the designation "fisheye" lens start at 18mm? I had a (one) photography class in June 2002 and then I bought a camera & started taking photos. I'm trying to fact check. Do you think that the bit about curved lines should be removed or rephrased? I take it, it seems misleading. Anyway, I hope I'm not harming the project adding this stuff. Best, and thanks, Koyaanis Qatsi 19:19 Jan 29, 2003 (UTC)
- No, no, no! On the contrary, this is extremely useful! In the Wiki world, the initial version of an article is never like the latest - things are developed! I think the distinction wrt. fisheye is the distortion, not the focal length. There are fisheyes > 18 mm and wide angles < 18 mm. But the shorter the focal length, the more difficult it is to get rid of the cushion 80.202.80.14
- Interesting stuff. I'd love to see a wide-angle lens >18mm which doesn't cushion the corners. Koyaanis Qatsi
- No, no, no! On the contrary, this is extremely useful! In the Wiki world, the initial version of an article is never like the latest - things are developed! I think the distinction wrt. fisheye is the distortion, not the focal length. There are fisheyes > 18 mm and wide angles < 18 mm. But the shorter the focal length, the more difficult it is to get rid of the cushion 80.202.80.14
- Right, I knew about the fisheyes. For 35mm cameras, doesn't the designation "fisheye" lens start at 18mm? I had a (one) photography class in June 2002 and then I bought a camera & started taking photos. I'm trying to fact check. Do you think that the bit about curved lines should be removed or rephrased? I take it, it seems misleading. Anyway, I hope I'm not harming the project adding this stuff. Best, and thanks, Koyaanis Qatsi 19:19 Jan 29, 2003 (UTC)
- It is usually called cushion, mea culpa. A perfect wide angle shall never produce curved lines. But even the best of extreme wide angle lenses always produce curved lines to a certain degree, esp. close to the image boundaries. So if you take a picture of a rectangle, it ends up looking like a cushion. A fish-eye is a lens where they have given up correcting this completely. See Aberration in optical systems.-- Egil 19:14 Jan 29, 2003 (UTC)
I'm taking the pics back out of the table, as for people with a narrow browser window the table is too wide. By simply sticking them next to each other, we let the browser wrap them into a column -- which is not as satisfying as seeing them in a quad arrangement, but vertical scrolling is much more comfortable for the web reader than horizontal scrolling. --Brion 19:29 Jan 29, 2003 (UTC)
Please note that the link to "Perspective Distortion: Source," added to the bottom of this article points to a new article in which the Conclusion is at variance with the conclusion with this article. Suggest this page is too flawed for minor editing and be replaced with Perspective Distortion, Source. See link at bottom.Pat Kelso 22:57 CST Jan 30, 2004
The title isn't OK this article is about perspective distortion and not lens distorsion (barrel distortion for instance). Ericd 09:51, 7 Mar 2004 (UTC)
- Perspective distortion, p e r - s e, has nothing to do with lenses. Please see Perspetive distortion, Conclusion. Thank you. Pat Kelso 18:46, Mar 7, 2004 (UTC)
- I will fully disagree, there are several form of perspective distortion, each time perspective is distorded for any cause there is perspective distorsion. The expression clear enough in itself to say what is "THE REAL" perspective distotion. This article deals about the influence of focal length on perpective representation in photography, it's a a important topic in photography, and this kind of distorsion has to do with camera lens. I'm was'nt a great fan of the previous title for the reason exposed before. But I find the present title worse because they are form of distortion (barrel & pillow) caused by the defect of the lens.
- BTW what is your new article about ? Seems to be about 3D to 2D projection isn'it ?
- If talking photography distortion w/photos, it is not my article ... Pat Kelso 21:09, Mar 7, 2004 (UTC)
- And please next time you want to change the title of and article use "Move this page" this will cause less confusion and keep the talk page relevant.
- As wikipedia is a collaborative effort can you help me to give accurate titles to the articles as my English is somewhat limited I have to idea how to solve this issue.
- Ericd 19:19, 7 Mar 2004 (UTC)
Sorry saw the 'move this page' suggestion too late. Will use in future if my poor brain can retain it that long. But have moved my part of Perspective distortion via cut and paste to Perspective projection distortion ... this to accomodate objection that 'persepctive' can refer to many other things.... Pat Kelso 19:47, Mar 7, 2004 (UTC)
- Please in the future use the "Move this page" method. -- Egil 20
- 07, 7 Mar 2004 (UTC)
- Yes sir. Pat Kelso 21:26, Mar 7, 2004 (UTC)
OK I move this one to "Perspective distortion caused by lens focal lenght" Ericd 19:56, 7 Mar 2004 (UTC)
Could also call it "Perspective compression and extension", since this technizue and be applied equally well for paintings (although not seen very often). Perspective distortion should be a pointer to the two articles. Ideally, both should be combined in one article.
-- Egil
Or could the article be called "Perspective change"? -- Egil 20:35, 7 Mar 2004 (UTC)
- I don't know all this needs some serious brainstroming to give some structure to the question. I remember an interresting article when I was much younger and new to photography. Some paintings have true perpective according to optical laws while other have faked perspective. Aùmong the interresting case in paintings is "La última cena" from Leonardo da Vinci that as an accurate super-wide perspective did Leonardo get this by geometry reasoning or by a "camera obscura" view ?
- Ericd 21:32, 7 Mar 2004 (UTC)