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Honored Contributor
Posts: 5,558
Registered: ‎06-25-2014

Re: Sharpness issues with 16-35mm lens


@ebiggs1 wrote:

:... find a nice large flat brick wall, and take a photo of it so that the brick wall ..."

 

I strongly advise against doing this.  It is almost useless on a ultra wide angle lens.  It won't tell you or indicate much to you.

You have one of two problems. Diffraction or de-centered.  One you can fix the other you can't.  My .02 cents and worth every penny.


The problem is that it doesn't really sound like diffraction, and an "L" lens is almost never decentered unless it's been dropped. Since the issue occurs only at the extremeties of the image, where depth of field is probably least helpful, I'd be more inclined to suspect front- or back-focusing. I'd at least run an AFMA check before sending it in.

Bob
Philadelphia, Pennsylvania USA
Esteemed Contributor
Posts: 3,854
Registered: ‎06-11-2013

Re: Sharpness issues with 16-35mm lens


@ebiggs1 wrote:

:... find a nice large flat brick wall, and take a photo of it so that the brick wall ..."

 

I strongly advise against doing this.  It is almost useless on a ultra wide angle lens.  It won't tell you or indicate much to you.

You have one of two problems. Diffraction or de-centered.  One you can fix the other you can't.  My .02 cents and worth every penny.


There will be a moderately spherical plane of focus.  I wouldn't expect it to be as sharp in the corners as compared to the center.  I'm more interested in seeing how much difference we're talking about and is it at least centered (symmetric).

 

So far we don't have any sample images to look at so we can't tell if it's normal or in need of service.

 

No lens will be as crisp at the edges as it is in the center... but some lenses are better than others.

 

Tim Campbell
5D III, 5D IV, 60Da
VIP
Posts: 13,997
Registered: ‎12-07-2012

Re: Sharpness issues with 16-35mm lens

"No lens will be as crisp at the edges as it is in the center ..."

 

Yes, this is the third most likely possibility.  It may be all the better the lens actually is. I have never shot one so I can not say from personal hands on experience. I did use the first version but did not own one. It isn't all that sharp to begin with.  I would expect Canon improved the new version II.

EB
EOS 1DX and 1D Mk IV and several lenses!
Honored Contributor
Posts: 5,558
Registered: ‎06-25-2014

Re: Sharpness issues with 16-35mm lens


@ebiggs1 wrote:

"No lens will be as crisp at the edges as it is in the center ..."

 

Yes, this is the third most likely possibility.  It may be all the better the lens actually is. I have never shot one so I can not say from personal hands on experience. I did use the first version but did not own one. It isn't all that sharp to begin with.  I would expect Canon improved the new version II.


The word from those who have tried them all seems to be that the new version of the 16-35 f/2.8 is sharper than the old one, but not quite as sharp as the slightly newer 16-35 f/4. I can't say, as I've used only the f/4. It's certainly plenty sharp.

Bob
Philadelphia, Pennsylvania USA
Super Contributor
Posts: 126
Registered: ‎09-13-2014

Re: Sharpness issues with 16-35mm lens

I can only give you my two cents worth, I have the lens, Version 1, I have utilized it on both of my cameras, Canon EOS 40D, Canon EOS 7D

 

I do not have the identical Version 2, however

 

I have never experienced the problem you have encounterd and I have utilized the lens on a wide variety of camera settings, my advice hopefully that if it was a recent purchase, warranty should cover it.

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