Caution: AUTO Mamiya/Sekor 55mm f/1.4

Discussion in 'Adapted Lenses' started by WNG, May 5, 2015.

  1. WNG

    WNG TalkEmount Hall of Famer

    Aug 12, 2014
    Arrid Zone-A, USA
    Heads Up folks!!

    I acquired this lens after all the good reviews, excellent photos, and internet hype.
    Well, be warned....this lens and ones like it, seem to have a technical flaw when used with a NEX or a6000. Can't tell you if full frame A7's will have this issue.

    I'm a bit surprised that Brian didn't have flare aberrations on his a6000. (Adapted Lens Showcase)

    My copy is the silver front focus barrel, black bodied, AUTO Mamiya/Sekor 55mm f/1.4. No A/M switch, and a silver aperture ring. M42.
    These are single-coated. And have a large flat rear element.

    The rear element seems to be reflecting bright light off the Sony sensor and casting a green flare onto the center of the photo.
    It does not move, it's fixed. Therefore not flare as we know it. As long as it's bright light conditions, the green blob is present.
    Stopped down to f11 or f16, it is quite focused. You can turn the focus ring until you see a perfectly focused hexagon from the iris blades!

    This is the first such experience with legacy lenses on my mirrorless body. I suspect other lenses with flat rear elements will potentially cause the same problem. I suspect the coating can not cope with a digital sensor. Film was darker and didn't have a glass aliasing filter in front of it either.

    A real shame....this lens is built wonderfully and the optical performance is superb.
  2. WoodWorks

    WoodWorks Super Moderator Subscribing Member

    Dec 12, 2012
    Ashland, OR, USA
    Before you write this lens off, you may want to check to make certain that the internal reflections aren't being caused by your adapter. I have had legacy lenses that under certain circumstances had awful flare issues that were resolved simply by switching to different brand of adapter.
  3. WNG

    WNG TalkEmount Hall of Famer

    Aug 12, 2014
    Arrid Zone-A, USA
    Very true. I've tried 3 M42 adapters so far, concerned if a shiny part of a flange could be causing it.
    But I get the same result with a Big_IS adapter that's been blacked out internally to eliminate all adapter reflection.
    Repeated myself, removed.

    Here's a pic of the green hex at f16, sharp as I defocus the subject.

    Last edited: May 6, 2015
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