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Canon FD lenses and the aperture blade issue- my " fix"

Discussion in 'Adapted Lenses' started by Minniesmum, Mar 25, 2012.

  1. Minniesmum

    Minniesmum Mu-43 Veteran

    371
    Mar 2, 2012
    UK
    Been reading alot about this and experienced it recently with a Canon FD 50mm f1.8. With the adapter the aperture blades are fixed wide open. There is nothing wrong with the lens as it works on a 35mm cam.
    So I fiddled with it. I attached the lens to my E-PL1 via the adapter. Once the adapter clicks into place it is fixed wide open. However I uncrewed the lens slightly counter-clockwise from the locked position. The lens is a tight fit onto the adapter so no danger of the lens dropping off.
    Bingo. The aperture blades then responded to me moving the ring on the lens- but only over a certain range. I then unscrewed the lens a bit further, the range changed but the aperture blades again responded.
    So I am now able to use the lens from wide-open to stopped-down. Can't judge precisely what the f-stop is but can guess. Works a treat. Not sure why but it does.
     
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  2. chromatin64

    chromatin64 Mu-43 Regular

    43
    Jan 10, 2012
    A Leekist in York, UK
    Russell
    I use a Fotodiox adapter with a "lock-open" ring; the ring has to be turned to the "lock" position to control the aperture with the aperture ring on the lens.

    Does your adapter have such a locking ring? It engages a prong that allows the aperture ring to do its thing. If you don't, adjusting the mount has a whole probably (accidentally) engages the prong and does the same job.
     
  3. I'm not sure of the exact issue you're describing. I've found that on my adapter you can't turn the breech lock as far as it should go (on the old FD lenses) which prevents me from stopping down below f/8 or f/11 depending on the lens. The breech needs to be turned the full way to allow the full range of apertures. It's no big deal though, since I wouldn't wiilingly choose an aperture smaller than f/11 on a m4/3 sensor anyway.
     
  4. napilopez

    napilopez Contributing Editor

    826
    Feb 21, 2012
    NYC Area
    Napier Lopez
    There is a trick to getting these adapters to work perfectly. All FD adapters I've seen have a lock and open position, so this should should work for you too. If not, I highly suggest you buy one such adapter from somewhere like amazon. It's only 23 bucks. I for one have the rainbowimaging(says fotasy on the adapter itself) adapter, which works perfectly aside from focusing past infinity.

    My Fotasy adapter works perfectly on my 50mm f1.4(and it did on the 50mm f1.8 too when I had that). So did my old adapter before I returned it to get the one I have currently, which is much cheaper.

    On amazon, someone wrote guide to properly working the adapter. If yours have and open and "lock" position, give these instructions a try:

     
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  5. Minniesmum

    Minniesmum Mu-43 Veteran

    371
    Mar 2, 2012
    UK
    Thank you. The adapter has no locking ring. Your explanation makes a lot of sense and explains what could be happening when I am adjusting the position of the lens in relation to the adapter. It works anyway !

    Cath
     
  6. harrysue

    harrysue Mu-43 Regular

    164
    Mar 12, 2011
    Will try to show what happens with the Fotasy adapter that has a locking ring. Should be two levers on the back of an FD mount. The one that's longest activates the aperture blades.

    [​IMG]

    When the lens is on the adapter, there should be a pin that pushes that arm to the right. Pushing it all the way to the right allows the aperture blades to do whatever the aperture ring says to do. In this case, the adapter ring is on "lock" which has the pin pushing full on the lever.

    [​IMG]

    This shows the adapter ring on "open". Now the pin doesn't touch the lever, it has moved to the left, and the lens will be stuck wide open.
    [​IMG]

    OK, your adapter doesn't have the open-lock ring. It still should have a fixed pin or arm to push the lever. When you assemble the adapter to your lens, look for that pin and make sure it is on the left side after assembly. You may have to position the adapter and twist so it pushes the lever closed before you lock it to the lens. In fact, this little step is also needed with the Fotasy adapter. Otherwise, the lever would also be on the wrong side of the pin even though our pin moves.
     
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  7. Minniesmum

    Minniesmum Mu-43 Veteran

    371
    Mar 2, 2012
    UK
    Thanks...will try this out now....;)
     
  8. Minniesmum

    Minniesmum Mu-43 Veteran

    371
    Mar 2, 2012
    UK
    It works !!! thanks ;)
     
  9. Minniesmum

    Minniesmum Mu-43 Veteran

    371
    Mar 2, 2012
    UK
    Thank you a TON ! My lens is now fully functional with adapter.
     
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