Should I be upset that my 18-200mm lens shows vignetting?
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Should I be upset that my 18-200mm lens shows vignetting?

David Shilman

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I posted the following question to a photography site, and got the 3 answers below.  I'd be interested in feedback from you folks.  Thanks!
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Q:  Should I be upset that my Canon 18-200mm lens shows vignetting?  When I have my lens zoomed all the way out to 200, vignetting is evident in the viewfinder and on certain shots (depending on background). Camera store guy tested my lens on another body, and it showed the same thing. He then tested a Sigma 18-200mm and it also showed vignetting. He said he'd never seen this before, and no one else had complained. He suggested I contact Canon. Any feedback on this issue would be appreciated.

A1:  Vignetting is normal for 18-200mm lenses at 200mm and wide open.  At maximum focal length and maximum aperture figure at least a mean corner fall-off of 62.2% or perhaps even more with some third party 18-200mm lenses.

A2:  It's the design limitation. A very long range zoom like that can't be expected to give you a shot like a prime (say, 135 mm f 2 L, 50 mm f 1.2 L, 100 mm f 2.8 macro), or an L zoom (Canon 24-70 mm f 2.8 L). Lower your expectation and enjoy what it can do for you, i.e. traveling photography and having to carry only one lens.

A3:  He never saw that before? He is lying or a moron.  Don't do business with that place anymore, bunch of idiots that won't tell you truth.  That lens and my lens and just about all 200mm zoom lenses vignette, heck a lot of lenses do.  I bought my 70-200 and it viggs. Is my lens bad or somthing? Of course not, its a wonderful lens, top of the line.  In Adobe Camera Raw, you can set up a profile that will read the lens and focal length, then a lens profile can be made that will automatically boost the corners when its zoomed out, so you don't have to deal with the vig issue.
« Last Edit: December 31, 1969, 07:00:00 pm by David Shilman »
David Shilman
Toronto, ON

"Always wave to the locals!"


Kin Lau

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Vignetting is normal, especially on super-zooms like the 18-200.

Many lens reviews also measure and include this info. Most lenses will vignette at the wide open setting.
« Last Edit: December 31, 1969, 07:00:00 pm by Kin Lau »


Brian Bailey

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I would agree with all of the above.

All lenses vignette to some degree, and the amount of vignetting is greatest at the widest aperture.  Generally, top quality lenses show the least amount of vignetting (almost zero), and it increases as you go down the quality scale.

When I look at lens reviews, vignetting is the least important defect to me because it's the easiest to correct with software and generally the least noticeable.  Sharpness, chromatic aberration, and distortion are all more difficult to compensate for in software.

Bottom line:  don't sweat it.  There are optical compromises in achieving the convenience of a 11X zoom!

BB
« Last Edit: December 31, 1969, 07:00:00 pm by Brian Bailey »
Brian Bailey
Etobicoke


Kin Lau

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To add to what Brian is saying, even top quality lenses will vignette my 55/1.2 vignettes alot, my 300/2.8 vignettes, my 70-200/2.8 vignettes, even my EF400/5.6L vignettes on a full-frame body (virtually none on a crop body like the 7D).
« Last Edit: December 31, 1969, 07:00:00 pm by Kin Lau »


David Shilman

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Thanks for the feedback, guys.  I guess I feel better.
« Last Edit: December 31, 1969, 07:00:00 pm by David Shilman »
David Shilman
Toronto, ON

"Always wave to the locals!"