Talk:Vignetting

I remember a lot of old pictures having an oval vignette. Is this wrong? I don't think I'm thinking of the mat. - Zepheus 21:41, 22 June 2006 (UTC)

applying an artistic vignette using software
I would like to add a link to a page on my website that deals specifically with making an artistic vignette using software.

I think this is important, as the vignetting effect has already been covered in this article, but there may well be people who, after reading the article, would like to have a go at reproducing the effect. This particular page on my website would achieve this.

Please let me know.

The page I have in mind is: http://www.digital-photography-tips.net/artistic-wedding-photography-vignette.html

--Dazp1970 09:22, 9 September 2006 (UTC)

Definition
I do not agree with the explanation of the term optical vignetting.

In my understanding, Vignetting is always caused by some kind of blocking of the light path.

The natural light-falloff (often wrongly named as natural vignetting) described by the cos4-law is not caused because the light-path is blocked somehow.

As I understand optical or technical Vignetting, it apears because the light has to pass throgh (at least) two 'holes' - no matter if they are apertures and/or lenses (or even mirrors).

Pages 12 of this pdf-file provides a very simple and consistent definition of 'Vignetting'. Also have a look at Page 11 for a rough explanation of the cos4-law.

I tried to make this clear on the german wiki-article.

Mschcsc 89.217.22.5 22:58, 24 February 2007 (UTC)


 * Sidney Ray, Applied Photographic Optics, 2nd Ed, page 33-34, on pinholes: "A very wide angle of view is possible but the image periphery suffers vignetting by cos^4 theta losses." Page 120, on Cos^4 theta: "The radial decrease in illumination is often called natural vignetting". Helen Bach 23:42, 12 October 2007 (UTC)

Remedy
The article states: "Optical vignetting [...] can be completely cured by a reduction in aperture of 2-3 stops." Surely this depends upon the severity of the vignetting. —DIV (138.194.12.32 (talk) 03:39, 15 July 2010 (UTC))

Contrast with mechanical vignetting
It seems to me that so-called optical vignetting is simply a subset of vignetting caused by a physical obstruction, and that the only difference from so-called mechanical vignetting is that in one the obstruction is located in front of the lens assembly, and in the other is located behind/within the lens assembly. —DIV (138.194.12.32 (talk) 03:42, 15 July 2010 (UTC))

Pronunciation?
i think this should be included in the page somewhere as it is a word prone to mispronunciation

example: video games
"Vignetting is commonly found on video games from the seventh generation." Where exactly? Which game or games? --96.251.75.52 (talk) 20:55, 5 June 2008 (UTC)
 * Loads of them, actually. Check any video games website for next-gen games screenshots. It's clearly a popular trend. --Hell Pé (talk) 12:46, 22 September 2010 (UTC)

Flash Vignetting
It is also possible to get Vignetting from a flash. This usually happens when the lens protrudes from the front of the camera, yet the flash is on or near the body of the camera itself. Under this circumstance, when taking photographs at an extremely close range, the lens itself may cast a shadow on the subject. This may not be considered "true" vignetting, but causes the same optical effect. —Preceding unsigned comment added by 192.25.240.225 (talk) 17:31, 8 June 2010 (UTC)

Pixel vignetting
The article currently states: "This is due to the non-square dimensions of the individual photodetectors." This sounds wrong. —DIV (138.194.12.32 (talk) 03:35, 15 July 2010 (UTC))


 * That sounds wrong to me too. I removed it. —Ben FrantzDale (talk) 13:40, 30 August 2010 (UTC)

Entrance-pupil foreshortening
I think what this page calls cos4 "natural vignetting" is due to the magnification—that is, if you have a wide-angle ideal pinhole camera and take a picture of a uniform-luminance hemisphere, the number of pixels per radian will approach infinity as you approach 90° from the optical axis, and so a finite ammount of light energy comming from that 89–90th degree of view is being stretched out over an infinite number of pixels,and so would be completeletely dark. (If so, that isn't explained clearly; I haven't done the math to see if that accounts for cos4 falloff.)

What I don't see explained is what happens if the entrance pupil is a disk in space (as is the case of a pinhole followed by a singlet), not a sphere as seems to be the case of most good camera lenses? It would seem that even if you were viewing a lambertian white flat surface with the image surface parallel and the optical axis orthogonal, you would get falloff by the cosine of the angle because the pixel corresponding to 45° off axis would be illuminated by all rays that came through the aperture at about 45° (exactly 45° in the limit of high f/#). Is this part of the cos4 falloff or is this a separate effect reserved for cameras with non-spherical entrance pupils? —Ben FrantzDale (talk) 13:39, 30 August 2010 (UTC)

Removed example of limited FOV
I removed this exmaple images, as they primarily show the effect of an limited FOV, and not so much vignetting ("reduction of … brightness … at the periphery compared to the image center").

--Tony Mach (talk) 07:41, 27 August 2013 (UTC)

First Reference (Van Walree's webpage on vignetting) invalid link
Very unfortunately the first link from the list of references is no longer valid (I did not check the ones further down though). Lodidol (talk) 21:31, 10 September 2019 (UTC)