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Thread: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!

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  1. #1
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    My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    A few days ago I got theCanon EF 70-200mm f/2.8 L IS II. []


    I have been very pleased with it...But I have just today noticed at 200mm in the corners at f2.8 are somewhat soft. Stopping down to f5.6 seems to help some.


    In the center it is not a problem, it is just in the corners.


    Here are some crops from corners. I took them with my Canon Rebel XSi. Imanually focused them in the live view.





    at f2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/IMG_5F00_9668.JPG[/img]


    And at f5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/IMG_5F00_9667.JPG[/img]


    Is it normal for theCanon 70-200mm f/2.8 L IS II to be soft in the corners at f2.8?


    Here are a couple more crops.


    At f2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/IMG_5F00_9702.JPG[/img]


    And at f5.6[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/IMG_5F00_9701.JPG[/img]


    Should I return my copy for a new one or not?


    What to you think?


    Thanks for any help!

  2. #2

    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Dang, if that is what you call soft, I'd dare you to look at my old sigma 28-70, even stopped down.


    I don't think it is unreasonable for a zoom lens to be slightly soft in the corners when wide open at the long end.


    You said you did a live view manual focus, where did you focus at? the center, or right on that spot? 2.8 at 200mm would make for a thin DOF, so if you're focusing on the center of the frame, the corners might not be on the same plain of focus. Just a thought.

  3. #3
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    I don't think it should be that soft. I suggest returning it. EDIT: realityinabox makes an excellent point: you can't evaluate corner sharpness if you didn't use the liveview 10X on the corner that you're examining.

  4. #4
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Daniel and realityinbox are right: before you return the lens, make sure you focused properly. It's not easy. I usually take 10 pictures and keep the sharpest. I use liveview at 10x exactly at the part of the picture I'm evaluating. (If you focus the center, the edges will be out of focus because the camera is probably not square to your target).


    Even the 70-200 II is not perfectly sharp in the corners. Here is a crop from the lower right corner of mine at 200mm f/2.8 taken with my 5DII:


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.93/Mk-2-lr.jpg[/img]


    It's a little tough to compare to the xsi because on one hand, unlike the pic from your rebel, it really is in the far corner of the 35mm frame. On the other hand, the pixel density on the 5DII isn't as high as that of the rebel, so your pic reveals more softness.


    Another thing to keep in mind: not all corners are created equal. My 70-200 has one corner (upper left) which is softer than the other three:


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.93/Mk-2-ul.jpg[/img]


    I actually considered returning mine, but in the end decided against it: the "bad" corner is still better than my Mk1's best corner, and if I returned my lens, maybe I'd get one with 2 bad corners. I just have no idea how common that is.


    By the way, many people report that the 70-200 II is as sharp as primes such as the 135mm f/2. Mine isn't quite as sharp as my 135 f/2 @ f/2.8, but the good corner is close. Here is crop from the corner of my 135 f/2 taken @ f/2.8:


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.93/135-lr.jpg[/img]


    I won't tell you if you should return your lens, but I hope some of this info is helpful.









  5. #5
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Thanks Guys!


    I used the 10x live view to focus in the same corner as those crops. I also used a tripod.

  6. #6
    Senior Member neuroanatomist's Avatar
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Quote Originally Posted by Elon Gane


    Thanks Guys!


    I used the 10x live view to focus in the same corner as those crops. I also used a tripod.



    I will say that Jon's images, which are from a FF camera, may not be directly relevant to you since the corner of his image is actually cropped away on your 1.6x FOVCF body. I'll try to shoot something with my 70-200 II on my 7D for comparison, but given what you've done so far,I'd return the lens (or send it to Canon for adjustment).

  7. #7
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Quote Originally Posted by neuroanatomist
    I will say that Jon's images, which are from a FF camera, may not be directly relevant to you since the corner of his image is actually cropped away on your 1.6x FOVCF body.

    Agreed- they're not directly comparable. On the other hand, if Elon judges the 1.6 FOVCF corner images much softer than my FF corner images (taking differing pixel densities into account), then something probably is wrong.



  8. #8
    Senior Member neuroanatomist's Avatar
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    If you look at Bryan's [url="http://www.The-Digital-Picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&am p;FLI=3&API=0&LensComp=687&CameraComp= 453&SampleComp=0&FLIComp=3&APIComp=3]ISO 12233 crops for 200mm f/2.8 vs. f/5.6[/url], you can see that at mid-frame and in the corner, the lens is a little bit sharper at f/5.6 than wide open.


    [quote=neuroanatomist]I'll try to shoot something with my 70-200 II on my 7D for comparison[/quote]


    Here are 100% crops from the extreme corner of a pair of shots taken with my 7D andEF 70-200mm f/2.8<span style="color: red;"]LIS II. Camera-to-subject distance was about 10 feet -DoF at 200mm, f/2.8 is less than 2 inches,so I chose a flat subject (the back of Michael Freeman's Perfect Exposure). Shots were tripod-mounted and lit with an off-camera Speedlite 430EX II placed at a 45&deg; angle about 3 feet from the book and wirelessly triggered with the 7D's built-in flash.


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.35.15/70_2D00_200II-corners.jpg[/img]


    As you can see, the f/2.8 image is a little less sharp and has a little less contrast. As Jon stated and Bryan's ISO 12233 crops show, a little corner softness wide open is normal for this lens (almost all lenses, in fact). The MTF/resolution tests at photozone.de also show slightly lower resolution at f/2.8 (not just in the corners) with this lens on a 50D.


    I should also point out that for the above test I disabled peripheral illumination correction in DPP, and had to bump up the exposure on the f/2.8 image by half a stop to compensate for the small amount of optical vignetting this lens has wide open (even on a crop body). I compared with vs. without PIC, and the correction actually seems to soften the corners by a tiny (very tiny) amount and reduce the contrast as it increases the brightness to compensate for vignetting.


    Obviously, since we're all shooting different scenes it's tough to tell for sure, but it looks (to me) like your images have a greater differential between f/2.8 and f/5.6 than mine (or Jon's before they disappeared).

  9. #9
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    Thanks everybody!


    Right now I'm leaning<span>against returning it because I will need this lens for the next two weekends and again two weeks after that. (I think it would probably take a fair amount of time to return and then get a new copy right?) By that time it will be to late to return in to Amazon. But I could send it to Canonfor adjustmentright? Would the warranty cover the costs?


    Anyway here are some more crops. I took them at 200mm with580EX II Speedlite bounced and with a tripod.


    Center at F2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/CenterF2.8.JPG[/img]


    Center at F5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/CenterF5.6.JPG[/img]


    Top left corner at F2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F2.8TopLeft.JPG[/img]


    Top left corner at F5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F5.6TopLeft.JPG[/img]


    Top right corner at F2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F2.8TopRight.JPG[/img]


    Top right corner at F5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F5.6TopRight.JPG[/img]


    Bottom right corner at F2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F2.8BottomRight.JPG[/img]


    Bottom right corner at F5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F5.6BottomRight.JPG[/img]


    Bottom left corner at F2.8


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/f2.8-BottomLeft.JPG[/img]


    Bottom left at F5.6


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.81/F5.6Bottom-Left.JPG[/img]


    So if you guys don't think it looks to bad I guess I will keep it for now.

  10. #10
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    Re: My Canon EF 70-200mm f/2.8 L IS II Soft at 2.8? Help!



    It would be a shame if you want to return the lens but are keeping it for just a few weeks of use. (Not saying you *should* return it, but if you want to, you should be able to).


    Amazon is very good about returns/exchanges. They might ship you a new one as soon as they get the old one, and you could probably have the new lens shipped next-day.


    You might even consider, instead of an exchange, buying another and returning the old one as a separate transaction.






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