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Vivitar 28 2.5 Stop Down No Friction?

Discussion in 'Adapted Lenses' started by Cruzan80, Jun 28, 2014.

  1. Cruzan80

    Cruzan80 Mu-43 All-Pro

    Aug 23, 2012
    Denver, Co
    Sean Rastsmith
    Hey All,

    Stumbled across a Vivitar 28mm 2.5 in m42 mount at an estate sale for $10. Even though I have and love the Close focus f2 I have, I decided to pick it up as it was "different" by having a stop-down ring along with the aperture. Listed as M15 on the Great Vivitar Bestiary. The only "issue" may be that the secondary ring (the one right below the aperture ring) is VERY easy to turn, and doesn't have any kind of click/detent at each end to keep it there. Is this normal for others who may have this kind-of unique lens or do I need to tear it down and replace something (perhaps someone de-clicked it)? From just holding the lens, I can even "bounce" the ring back off the hard stop at either end, so it will be a "make sure it is open" kind of thing. However, focusing should be easier since I can set the aperture, open it up, focus and then stop down without counting... I have also heard that the bottom-most ring is a T-m42 adapter that was put on the lens initially. Can anyone confirm/deny?

    Also, anyone have any experience with a m42 to MD adapter? Instead of picking up another whole adapter, just stacking would be cheaper (and could really be cheaper if I invest in a second mirrorless system).
     
  2. edmsnap

    edmsnap Mu-43 Veteran

    430
    Dec 20, 2011
    Edmonton, Alberta
    I've never seen that Vivitar before, but it appears to be a preset aperture lens which means that it's working exactly as designed. You set the aperture you want on the preset ring, focus wide open, then stop down the aperture ring with a quick spin and take your photo. There would be no point to having that ring with click-stops as that's not how it's designed to work. Personally, it's still my favourite type of aperture as you never have to look up from the viewfinder to know if you're at the aperture you want to be at.
     
  3. Cruzan80

    Cruzan80 Mu-43 All-Pro

    Aug 23, 2012
    Denver, Co
    Sean Rastsmith
    The only reason I was thinking of "click-stops" was at either end, to hold it there once I spun the dial, to stop it from bouncing back. Maybe I am overthinking it, and once it is mounted, it won't be a problem. Just was wondering if anyone else had experiences with this particular flavor. Seems to be decently rare (ebay had none in the completed sales, and haven't seen any for sale here).
     
  4. fortwodriver

    fortwodriver Mu-43 Top Veteran

    958
    Nov 15, 2013
    Toronto, Ontario, Canada
    Frank
    I have a Zenit and a Rokkor that work exactly the same. The stop-down ring is very loose and can practically be flicked to open or close to the set aperture. I could never really prove it because I always shot fast negative film, but I felt that the mirror bounce on one of my older cameras would cause enough backlash to make that ring slide just a bit at exposure.

    I've never seen a manual stop-down lens that had clicks at either end made by a third-party manufacturer.
    They either had a loose ring you could flick, or an A-M switch towards the mount-end of the barrel like one of my other, more recent Rokkor lenses.