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Four thirds lens with OM-M43 adapter

Discussion in 'Adapted Lenses' started by djtaylor7, May 25, 2019.

  1. djtaylor7

    djtaylor7 Mu-43 Top Veteran Subscribing Member

    Mar 2, 2013
    Nelson, NZ
    Am curious. Have seen someone using a Four Thirds lens on an E-M5 Mkii with an OM-M43 adapter. Will this provide any control of the aperture?
  2. Phocal

    Phocal Mu-43 Legend Subscribing Member

    Jan 3, 2014
    Yes it will, but don’t expect very good performance. The lenses are designed for PDAF and don’t focus well on a camera using CDAF. You need an EM1 to make good use of them. There are a few that are CDAF optimized but even those don’t work nearly close to native.
    • Informative Informative x 1
  3. jimr.pdx

    jimr.pdx Mu-43 Veteran Subscribing Member

    Dec 5, 2010
    ~1hr north of Portland OR
    Jim R
    Er.. OM adapter not 4thirds?
    • Like Like x 1
  4. tkbslc

    tkbslc Super Moderator

    OM-M43 adapter will adapt OM mount lenses to m4/3. I'm not sure why you'd try to use it with a regular 4/3 lens, but no, it cannot work.

    The do make 4/3-m4/3 adapters with full electronic control, but they work a lot better on an E-M1 with PDAF. You'll want to stick to CDAF optimized 4/3 lenses if you go that routr.
    • Informative Informative x 2
  5. djtaylor7

    djtaylor7 Mu-43 Top Veteran Subscribing Member

    Mar 2, 2013
    Nelson, NZ
    Thanks all. This was something I saw on an auction website and it confused me. This was a four thirds 40-150mm with OM-M43 adapter. Could not see how it would work.
    Subscribe to see EXIF info for this image (if available)

    I have a MMF2 myself which has the contacts, and had realized four thirds and OM had the same flange. But this looks like it is focus by wire and does not have any aperture ring. But seller tells me it works in manual mode.
  6. tkbslc

    tkbslc Super Moderator

    OM and 4/3 do not have the same flange. 4/3 is 38.6mm register depth and OM is 46mm. There was room to mount OM lenses with a slim adapter on 4/3 cameras.

    4/3 and OM are not even the same diameter, so there is no way you could mount it on that adapter. Seller is confused.

    That's a regular old 40-150mm. You could get a first version m4/3 version of that lens for $50-60 used, so no reason to buy a 4/3 adapted version.
    • Informative Informative x 1
  7. barry13

    barry13 Mu-43.com Editor Subscribing Member

    Mar 7, 2014
    Southern California
    I never noticed before how similar the mounts are.
    However, an OM lens I just tried won't fit on the MMF-3.

    That lens is focus by wire; only the SWD lenses can be truly manually focused. So you won't be able to focus without a smart adapter, and the aperture won't move.

    You can get a refurb mu-43 40-150mm for $49, or sometimes $99 new, so I wouldn't bother with this if you don't already have a working adapter.
    • Agree Agree x 2
  8. djtaylor7

    djtaylor7 Mu-43 Top Veteran Subscribing Member

    Mar 2, 2013
    Nelson, NZ
    Agreed. This is one auction I am not going to bother with. I don't need another E-M5 Mkii anyway.
    The mounts are very similar. The body caps and lens caps are interchangeable, but as you say the OM lens stop down lever fowls on the 4/3 mount.
    I have an OM to 4/3 adapter ring, and it is 7mm think (to force the iris to close from the look of it). So the 4/3rds lens on the OM adapter that I showed the picture of will have a 7mm extension ring built in.:) .
  9. StephenB

    StephenB Mu-43 All-Pro Subscribing Member

    Aug 29, 2018
    Somerset UK
    I bought the 4/3 9-18 in error but decided to keep it as I thought it performed better than my Canon 17-40 L lens, it came with a Chinese adaptor which wasn't great, I then bought an Oly MMF-3 for a bargain price (£70). I use it with my EM10/2 and EM5/2 primarily for landscapes and indoor stuff. It's a great lens and I have no need for any other. The auto focus is a little slow. It's great for sunsets and lens flare is seldom, although I did get some in this shot.

    P5030013a v 2k.jpg
    Subscribe to see EXIF info for this image (if available)
    • Like Like x 5
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