OM adapter vignetting on A7?

Discussion in 'Adapted Lenses' started by mcwc, Jan 9, 2015.

  1. mcwc

    mcwc New to TalkEmount

    7
    Jan 9, 2015
    Vancouver, BC
    I have an OM to NEX adapter from big_is on eBay that I'm using on my A7.

    I don't know if it is the adapter or the lens but it seems to vignette on lenses wider than 35mm, wide open and stopped down to f8. No lens hoods were used.

    The lenses are a Vivitar 28mm f1.9 Series 1 and a Zuiko 28-48mm f4.

    Has anybody else experienced this with cheap OM adapters or is it just the lenses? Is there a better brand or seller of adapters that I should get?
     
  2. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    I have an A7 and various OM adapters from Novoflex, Fotga and Pixco. Never noticed vignetting that I blamed the adapter for and I've used OM lenses from 21/3.5 through a 75-150/4, including the 35/2.8 Shift. If the adapter causes vignetting, it should become more sharply delineated with smaller apertures, so stop down the lens as far as it goes and check for vignetting then.
     
  3. mcwc

    mcwc New to TalkEmount

    7
    Jan 9, 2015
    Vancouver, BC
    The amount of vignetting reduces as the lens gets stopped down but it is still noticeable.

    I adapted the 28-48mm f4 to my Nikon D600 with a homemade Leitax style mount adapter, made from a M42 to F-mount adapter and doesn't allow for infinity focus. Using the lens on my D600, there is a little bit of vignetting wide open and it goes away when stopped down. So, that should rule out the lens being the problem...
     
  4. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    I wouldn't be too sure about that. Most lenses vignette less when focussed closer. You really have to compare when focussed on infinity. I can hardly imagine the adapter being the problem, when the vignetting gets less on stopping down.
     
  5. Dan Euritt

    Dan Euritt TalkEmount Regular

    191
    Jan 11, 2014
    the adapter doesn't have any glass in it, right? post up a pic of the inside of the adapter.

    cheap adapters are usually just a big hole on the inside, no possible way that they can cause any vignetting.
     
  6. mcwc

    mcwc New to TalkEmount

    7
    Jan 9, 2015
    Vancouver, BC
    Shimming the adapter for infinity helped in reducing the vignetting. Here are some test shots, shot on two different days.
    Zuiko%2B28-48mm%2Badapter%2Bshim%2Bcomparision.

    Here is a photo of the adapter, it's just a tube with mounts.
    DSC_1966.JPG