C.Steele Senior Member  254 posts Likes: 1 Joined Nov 2006 Location: Portland, OR More info | Apr 17, 2008 18:07 | #1 Is this normal at 10mm? I just bought a Sigma 10-20 and notice quite a bit of vignetting at 10mm. I have never used a lens this wide before, but I read a ton of reviews and none mentioned this. Maybe it's just a given? The lens is sharp and works well, but noticeably lighter in the middle. Just wondering if I got a questionable copy. Just new buyers panic I guess. Sometimes I do get to places just when God's ready to have somebody click the shutter. -Ansel Adams
LOG IN TO REPLY |
Bendel Senior Member  323 posts Joined Jan 2008 Location: Wisconsin More info | Apr 17, 2008 18:27 | #2 Can you post a sample picture? Brandon
LOG IN TO REPLY |
05Xrunner Goldmember, Flipflopper.  More info | what camera are you using it on. My gear
LOG IN TO REPLY |
Kruzkal Senior Member 393 posts Joined Apr 2008 More info | Apr 17, 2008 18:46 | #4 Vignetting is normal for ultra wide lenses wide open.
LOG IN TO REPLY |
canadianbacon52 Senior Member 250 posts Joined May 2007 More info | Apr 17, 2008 18:50 | #5 To be honest I never noticed it, obvious question, but are you using any filters? Some filters (not all) will cause vignetting..
LOG IN TO REPLY |
05Xrunner Goldmember, Flipflopper. More info | same here..I never noticed anything wide open at 10mm on a 1.6x My gear
LOG IN TO REPLY |
acorean Senior Member  586 posts Joined Nov 2006 Location: Boston More info | Apr 17, 2008 19:01 | #7 I haven't noticed anything vignetting on my Wigma. A polarizer will give you uneven skies. Stacking filters will most definitely give you vignetting. -C
LOG IN TO REPLY |
canotographer Senior Member  810 posts Joined May 2007 More info | Apr 17, 2008 19:08 | #8 no vignetting on mine... Mark
LOG IN TO REPLY |
macropod Member  108 posts Joined Nov 2007 Location: Australia More info | Apr 17, 2008 21:36 | #9 Light fall-off on ultra-wide lenses is quite normal. According to canon EF Lens Work, the cos4 law: states that light fall-off in peripheral areas of the image increases as the angle of view increases, even if the lens is completely free of vignetting. The peripheral image is formed by groups of light rays entering the lens at a certain angle with respect to the optical axis, and the amount of light fall-off is proportional to the cosine of that angle raised to the fourth power. As this is a law of physics, it cannot be avoided. However, with wideangle lenses having a large angle of view, decreases in peripheral illumination can be prevented by increasing the lens’ aperture efficiency (ratio of the area of the on-axis entrance pupil to the area of the off-axis entrance pupil). For a lens with a 90 degreee FoV, the cos4 law dictates that the amount of light reaching the corners of the film/sensor is only a quarter the intensity of the light in the center. Depending on how succesful the manufacturer is at increasing the aperture efficiency while keeping everything else under control, the amount of light fall-off might be less. To see how the Sigma fares in comparison to a range of other lenses, go to:
LOG IN TO REPLY |
MinisterStanley Senior Member  293 posts Joined Dec 2004 More info | Apr 17, 2008 21:39 | #10 When I owned this lens (on my 20D) I never noticed any at all even wide open. -Prodigal Son
LOG IN TO REPLY |
TeeWhy "Monkey's uncle"  10,596 posts Likes: 5 Joined Feb 2006 Location: Pasadena, CA More info | Apr 17, 2008 22:54 | #11 Is the hood on properly? Do you have more than one filter on? Gallery: http://tomyi.smugmug.com/
LOG IN TO REPLY |
RoyWebber Goldmember 3,187 posts Likes: 7 Joined Nov 2006 Location: Corralejo, Fuerteventura....Canary Islands Spain More info | Apr 18, 2008 00:44 | #12 No Problems with my Canon 10-22 Canon 7D, 40D,100-400 IS L, EFS 15-85 IS, EFS 10-22-With Faulty USM, 055XPROB+488RC2, 430 & 580 II Flash, Tokina 11-16mm f/2.8-
LOG IN TO REPLY |
This is an image SoC - 10mm wide open @ F4
Oops, that was F8, this is F4
Sometimes I do get to places just when God's ready to have somebody click the shutter. -Ansel Adams
LOG IN TO REPLY |
TeeWhy "Monkey's uncle" 10,596 posts Likes: 5 Joined Feb 2006 Location: Pasadena, CA More info | Apr 18, 2008 01:17 | #14 Yup a small amount of vignetting, not unusual for any lens to have. Gallery: http://tomyi.smugmug.com/
LOG IN TO REPLY |
So that looks totally normal and acceptable? I have never noticed it on my other lenses, but then again I've never had one this wide either. I personally don't find it bad and it could be delt with very easily in LR if need be. I just want to make sure that this is normal for this lens and I don't have a bad copy. It's sharp as heck, that's for sure Sometimes I do get to places just when God's ready to have somebody click the shutter. -Ansel Adams
LOG IN TO REPLY |
 | x 1600 |
| y 1600 |
| Log in Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!
|
| ||
| Latest registered member is Mihai Bucur 1188 guests, 167 members online Simultaneous users record so far is 15,144, that happened on Nov 22, 2018 | |||
| 
