Zenzanon 40mm Chromatic Aberration?

Discussion in 'Medium Format' started by john_beneke, Jul 1, 2010.

  1. I've noticed that my 40mm Zenzanon S shows some pretty serious chromatic aberration at times, I know that these lenses have a corner sharpness issue, but for a professional lens, the chromatic aberration is unacceptable, and I wanted to know if this was normal for these lenses, or specific to mine.
    The attached pictures are 100% crops and they do look a little soft because the picture they were taken from was shot handheld at a 15th, and my hands aren't too steady.
    [​IMG]
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  2. John, I don't know what to say after looking at your images. I've certainly never noticed any chromatic aberration from my 40mm PS Zenzanon - a lens I use a great deal for landscapes. Regarding your comment about there being a corner sharpness issue with this lens - well that's the first I've heard of it.
    I have heard people say it suffers from curvilinear distortion, which is something else I've never seen in any of my transparencies. To prove it, here's an image I've posted before with an enlargement of the top corner.
     
  3. david_henderson

    david_henderson www.photography001.com

    I have the S version and though I don't use it a great deal, I haven't seen anything like that from it. Are you sure this is on the neg/transparency rather than appearing during scanning?
     
  4. Sorry, image didn't work, here's a second attempt.
     
  5. And a third attempt for the corner. I don't know how to post two images at the same time!
     
  6. My apologies for the last image - I forgot to convert it to a Jpg!
     
  7. That's a lot of fringing. My guess is that the lens was assembled wrong. Either an element was put in reversed or an element was the wrong glass type. Given what you have said, what you are seeing is probably Lateral Chromatic. If the diaphragm doesn't reduce it when stopped down, that's what it is.
     
  8. steve:
    Thats what I'm guessing, when I first bought the lens off ebay, I noticed that the pedal hood was loose, so I took off the name plate that held it together, and made a gasket out of tape in order to keep the pedal in place, also there is a series of dings on the pedal hood, that look like they were caused by concrete. I'm guessing the previous owner dropped it, and either got it repaired incorrectly, or didn't get it repaired. And stopping the lens down makes no difference, its the same at every aperture.
    Its not an issue with scanning, because images my other lens (80mm s) look totally fine.
    Would it be worth it to get this lens fixed? I mean, it is the lens I use the most... But how much will that cost?
     
  9. CA can also occur in the scanning process.
     
  10. Thanks for the images Dave, I wish my pictures looked like that!
     
  11. I guess "getting it fixed" depends upon how much you paid for it. If you paid a lot, fix it. If you got it for cheap, just buy another one.
     

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