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Is my SEL24F18 Decentered :(

Discussion in 'Sony Alpha E-Mount Lenses' started by Noor, Jan 25, 2016.

  1. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    Hello ,

    The Sony Zeiss 24mm is supposed to be among the best APS-C e-mount lens optically , however I have noticed softness in my images so I did a quick test...

    When I focus for the best sharpness on the right side , the left side is OOF and vice versa. I can try to compromise between left and right sharpness and I get less then optimal sharpness on both sides. Stopping down to f/8 f/11 helps to some extent.

    Sample 1

    @f2.8
    Right side in focus:

    r.JPG

    Left side in focus:

    l.JPG

    Attempted compromise:

    l.JPG

    Sharp across the frame at f/8

    _DSC0089.JPG

    Sample 2:

    @2.8
    Right side in focus:

    r2.JPG

    Left side in focus :

    l2.JPG

    Sharp across the frame at f/8

    f8.JPG

    For some reason I can't upload these to the forum , just double click to view at 100%

    Would appreciate some feedback , do you believe this lens is faulty ?
     
  2. SpaceManSpiff

    SpaceManSpiff TalkEmount Top Veteran

    547
    Dec 13, 2013
    Tucson, AZ
    Eric
    Welcome to the forum, Noor!

    I don't think your lens is decentered. From what I have read (I don't own this lens) this lens can deliver great images with great center sharpness but the edges lag behind and aren't with the program until past f/2.8. From what I understand it was optimized to work better at close and mid-focusing distances rather than towards infinity.

    HTH,
     
  3. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    Thanks ! If that is the case this might not be the best lens for me as I do a lot of nightscapes and landscapes ...
     
    Last edited: Jan 26, 2016
  4. WNG

    WNG TalkEmount All-Pro

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    Looks OK once stopped down to f/8. If it was de-centered, the blurred softness would still be present.
    More likely DOF due to f/2.8 and the backgrounds are at different distances.
    Best DIY test is to shoot perpendicular towards a brick/concrete wall. Focus peaking activated. Focus for center sharpness at each aperture.
    You should see the colored peaking move in and out of center equally. And at small apertures, the peaking is consistent across the frame.

    Shooting landscapes, you really shouldn't be using anything less than f/9 anyway.
     
    • Agree Agree x 1
  5. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    Isn't the hyperfocal distance around 11m ? , shouldn't all objects father then 11 meters be in focus when when I focus @infinity.. I really can't wrap my head around this !
     
  6. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    I've downloaded the full-res images and judging from those I'd return the lens right away if possible, there shouldn't be such a difference between left and right at f/2.8 and I'd want the image sharp across the frame at f/8 which it isn't really. Disclaimer: I'm one picky guy when it comes to sharpness in landscape-type shots.
     
  7. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    I got it used a year ago for a "bargain" price (470$) , I was new to photography back then so I could not detect this issue.. I assume they can't service it where I live (Dubai) and they will send it abroad and charge a fortune :(

    Selling it away to the next unsuspecting person is not something I would consider ..
     
    Last edited: Jan 26, 2016
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  8. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    I've sold a lot of lenses that were more or less decentered. Heck, almost each lens is decentered to some degree. I always offer full-res sample images of lenses I sell, it's up to the buyer to decide if image quality is satisfactory. If a buyer chooses to pick up the lens in person, he's responsible for testing on the spot, like I do myself when buying in person. So far no one has ever complained about lens defects afterwards.
     
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  9. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    You do have a point , but still puts me in an ethical dilemma !
     
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  10. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    I'm quite sure that Sony will state that the lens performs within specification if you'd send it to them for repair/replacement. I've done a similar exercise two times, once with a Nikon lens and once with a Panasonic MFT lens and both performed worse than your 24mm. And Sony's quality control doesn't seem any better than that of Nikon or Panasonic, to put it mildly.

    So the question is: is it morally defendable to resell a lens as technically OK if the manufacturer wouldn't honor a guarantee claim for said lens? My answer is yes, YMMV of course :).

    Hope this helps with your dilemma.
     
    • Like Like x 1
  11. SpaceManSpiff

    SpaceManSpiff TalkEmount Top Veteran

    547
    Dec 13, 2013
    Tucson, AZ
    Eric
    Noor, IMO it wouldn't be unethical to sell this lens with full disclosure as to why you are selling it, and with some sample images (good and bad, of course). At the bargain price you bought it for, you could surely sell it to someone who is looking for a low-light wide angle for purposes other than landscapes (indoors, people, food).
     
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  12. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    Yes it would do well for these purposes , and pics are actually sharp across the frame in close and medium ranges .. I guess with an honest post along with a few samples (good and bad) and a fair asking price would it would be okay to sell ..
     
    Last edited: Jan 26, 2016
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  13. soopadoopa

    soopadoopa TalkEmount Regular

    68
    Jun 3, 2015
    i'll give you a couple bucks for it :biggrin:
     
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  14. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    @Noor@Noor Did you do the brick wall test?
     
  15. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    Not yet , I'll try that sometime this week , can't find a brick wall in my vicinity !
     
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  16. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    I will contact you if I finally decide to sell :biggrin:
     
  17. soopadoopa

    soopadoopa TalkEmount Regular

    68
    Jun 3, 2015
    my hammer is standing by my piggy bank...
     
  18. Andromeda143

    Andromeda143 TalkEmount Regular

    47
    Dec 19, 2015
    Melbourne, Australia
    Clive Dickinson
    Hyperfocal distance is aperture dependent H = f^2/cA approx where f = focal length c = circle of confusion and A = aperture
     
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  19. Noor

    Noor TalkEmount Regular

    116
    Jan 25, 2016
    Noor Arnaout
    I have printed a test chart at work using a plotter to test my SEL24F18 .. (no brick walls here !)

    Test Chart : ISO 12233 Test Chart

    I printed it at 400x240 as indicated in the web page ..

    My Alignment is probably not perfect , but all attempts are yielding the same softness at the left side


    @f/1.8
    _DSC0370.JPG

    @f/2.8
    _DSC0371.JPG
    @f/5.6
    _DSC0372.JPG
    @f/8
    _DSC0373.JPG
     
    • Informative Informative x 1
  20. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    Yeah, it's decentered. I would send this test and the lens back to Sony if possible. I would think they would either correct it or replace the lens depending on how long you've had it.