1. Reminder: Please use our affiliate links for holiday shopping!

Showcase Mamiya Sekor 55mm f/1.4, m42 mount

Discussion in 'Adapted Lens Sample Image Showcase' started by eno789, Nov 25, 2013.

  1. eno789

    eno789 TalkEmount Top Veteran

    720
    Jan 1, 2012
    NoCal, USA
    Brian
    Last edited: May 6, 2015
    • Like Like x 6
  2. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    I might have same lens with Porst name. These may be made by Tomioka. Soft wide open but pretty good from about 2.8. Nice lens for portraits but totally horrible with lens turbo wide open.
     
  3. WNG

    WNG TalkEmount All-Pro

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    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 samples.

    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.
    These are single-coated.

    The flat 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.
     
  4. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    One problem with legacy lenses is that there may be several versions of the lens that work ok with film but some versions work with sensor and some don't.

    If the rear element is flat there will be multiple reflections between sensor and rear lens (like having two mirrors parallel). The coatings are wavelength dependent and remove more reflections from some wavelengths than others.

    I am going to experiment painting adapters with a black paint (Tetenal Total Mat or something like it) because I think that some of my legacy lenses suffer from lack of contrast because of reflections.
     
  5. eno789

    eno789 TalkEmount Top Veteran

    720
    Jan 1, 2012
    NoCal, USA
    Brian
    WNG, Sorry to hear your bad experience. Some info about my copy,

    1) Mine is all black with A/M switch, so some difference there.
    2) On the front, printed as "AUTO mamiya/sekor 1:1.4 f=55mm No. 129nnn".
    3) Rear element looks pretty flat as well.
    4) My copy has some light hazing near the rear element - maybe it cancels the sensor reflection? LoL.

    The above autumn leaves shots were using a 5N, not a6000. So the sensor is a little different. I'll try it on my a6000 or a7 when I get a chance.
     
  6. WNG

    WNG TalkEmount All-Pro

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    Thanks for responding Brian, and xXx1.

    One of the adapters (Big_IS) I tried came blacked out internally to address internal reflections. So, yes, this is an issue degrading image quality.
    I believe the coating that came on this lens isn't able to cope with the reflectivity of the aliasing filter. It is a film era lens after all.

    My copy has the same lettering and its serial no. is 75462. It also has the slightest bit of haze on one side of the rear element, but barely visible. So, that's something similar. :)
    Ah, I assumed it was on your a6000. My bad!
    I read somewhere that the NEX-7 and the Lens Turbo produced the same problem. The later Lens Turbo 2 corrected the 'blue spot'.
     
    Last edited: May 6, 2015
  7. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    Yes, LT I generated a blue spot with some lenses. Unfortunately LT II won't work with all the lenses as elements will collide.
     
  8. eno789

    eno789 TalkEmount Top Veteran

    720
    Jan 1, 2012
    NoCal, USA
    Brian
    More samples with A6000

    DSC01397.

    DSC01400.

    DSC01411.

    DSC01416.

    Wide Open, it's not biting sharp, but sharp enough for me.
    DSC01435.

    DSC01402.

    Stop Down
    DSC01428.

    DSC01421.


    I don't see the problem Will has, at least on my copy.

    More pictures in the album https://goo.gl/s0YBr7 (Mamiya Sekor 55/1.4 on A6000, Mamiya Macro Sekor 60/2.8 on A7)
     
    Last edited: May 9, 2015
    • Like Like x 5
  9. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    Interesting bokeh.
     
  10. WNG

    WNG TalkEmount All-Pro

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    Gorgeous effort as always, Brian. Thanks for following up here and on MFLenses.

    Looks like only particular revisions of lenses do this. And only with certain cameras. Live and learn.

    I can still use it for wide open shooting at least.
     
    • Like Like x 1
  11. Nexnut

    Nexnut TalkEmount Top Veteran

    I love the way this lens renders OOF areas and highlights, especially in the first set. I got a copy in a box somewhere, but have to wait until all my stuff has been shipped.
     
    • Like Like x 1
  12. Sympa

    Sympa TalkEmount Rookie

    15
    Sep 19, 2015
    My copy (sn 63xxx, silver aperture and nose, A/M switch) is very glowy wide open. And when focuing close at half a meter it is very very blurry in the corners. Lots of coma. The rear element is convex. When I get a good M42 adapter I will check if it fits on the LT2. With my sloppy ring, it collides with 2 pieces of paper as a margin.