OM Mount Weirdness

Discussion in 'Olympus' started by davecaz, Jun 13, 2018.

  1. Hi,

    I'm hoping someone can tell me what's going on with one of my Olympus OM System lenses. Specifically, the 65-200mm f/4 Zuiko Auto Zoom.

    I have an OM-1 and an OM-2, both with 50mm lenses. Either 50mm fits on either camera body, as expected. The 65-200 does not fit on either of them. When I try to mount it, the lugs align and it seems to mate but, when I try to twist it into position, it will only turn about 1/3 of the distance required, at which point it feels like it's binding.

    The mounts are visibly different between the 50s and the zoom. The two 50s are the same design, but the zoom does not have the "OM shield" and it has spikes where the 50s don't.

    I'm not very good at this sort of thing, but I tried to take photos to demonstrate what I mean. Here is the trio.
    This is one of the 50s, showing the "shield".

    This is the zoom, with the "spikes" on the left. 20180613_093914-SM.jpg
    And, just to prove that I didn't accidentally grab the wrong lens, here's the other end.

    I have several other OM lenses. All of them except my 135mm f/3.5 have a "shield", though the size varies. The 135 has no shield, but also lacks the spikes on the zoom's mount. All of the other lenses mount without any trouble. I don't believe any of them have that SAEA marking, either.

    Any idea what I'm running into, here? Thanks!
  2. paul ron

    paul ron NYC

    thats strange. i have to check my om.
  3. Agreed
    jim_momary likes this.
  4. m42dave

    m42dave Dave E.

    Are you able to look at the back of the lens mount with the shutter held open on Bulb?
  5. I've had several OM system lenses, "spikes" have nothing to do with compatibility, since some of my 50 mm lenses had spikes, while others had bent metal plank instead of spikes and mind you, they ALL fitted all of my OM bodies, which are: OM-1, OM-2, OM-2S, OM-4, OM-10, OM-40. I never had 65-200 mm so I can't speak for it, but it would be a good idea to measure bayonet teeth and compare then with any other lens which is compatible to your OM body.
  6. Sorry, Dave. You lost me on that one. I can't use Bulb unless the lens is mounted, and I can't mount the lens. If I could, I wouldn't be able to see the lens mount.
    Yep. I wasn't saying the spikes were to blame, I was just pointing out any noticeable differences. I don't think I have any measuring tools accurate enough to measure the bayonet lugs (teeth).
  7. It's pretty apparent from your photos, that the zoom lens has sustained multiple impacts.

    Tolerances are tight on Pro level precision equipment like in the OM system, so a shock or impact to a sensitive area can
    certainly cause 'binding' or out-right malfunction.

    BTW, I also own the 65-200mm Zuiko Zoom; if its free of fog/haze, without even having to qualify it as an early 80's zoom, it's a superb image producer !
  8. Is it? It's certainly possible, but I must be missing the signs. Could you tell me what you're seeing that leads you to that conclusion, so I might not have to post a similar thread in the future?
  9. Vincent Peri

    Vincent Peri Metairie, LA

    I can see two separate impact areas on the filter ring. From my experience, you'd really have to whack the lens to dent the ring. Gus can probably list some other indications.
  10. m42dave

    m42dave Dave E.

    You may not be able so see the mount flange itself, but I was thinking you might be able to see where other parts could be binding. Not sure about the OMs, but on my Pentax K-mount SLRs Bulb will operate even if the lens isn't fully mounted.

    I've not used the 65-200 , but when I had an OM-1 35 years ago, I always thought the lenses felt somewhat tight and "dry" when mounting.
  11. Actually, my OM-1D felt very smooth mounting lenses, much more than the AF Nikons to which I switched, festooned with autofocus linkage. When I shot Olympus, I never had the 65-200.

    To me, the 65-200mm does look damaged. Maybe it's the lighting, but the "spikes" look like something has worn or broken off.
  12. paul ron

    paul ron NYC

    thats not a bad idea... open the back with no lens mounted. open the shutter in B. now examine how the lens mounts? mmmm but i wonder if it will allow you to mount a lens with the shutter open?

    i doubt a couple bangs or a dinged filter ring would effect mounting it. the mount looks to be in good condition.
  13. Possibly you're looking at the built-in hood, which is the outermost ring? The filter ring is just outside the "beauty ring", with the lens specs printed on it. I see the dings on the hood. I don't see any on the filter ring.
    Ahhhh! Now, I get what you mean. I don't know. I'll look and see. Some of my OM Lenses are tighter than others, but the zoom is a whole different category beyond tight.
    Agreed. They do show wear/damage. I don't know their function, so I don't know if it's relevant, or not.
    Yeah, I'm going to try that, now that I understand what Dave meant. I had the same thought about the dings on the front being unlikely to affect the lens mount, but I don't know for sure.
  14. My Zuiko 135 f/2.8 fell from the shelf, from around 6 foot height, landed on the floor and bent the lens mount. It still fits as it should and all, but infinity is a bit off. I need to stop down to f/11 to achieve focus on infinity. But my lens fell on the "butt", aye, with cap on and all, but still.

    And some of my other lenses, like Pentax 50 mm f/2 and Soviet Helios lens landed on their filter rings, bending them heavily. Nothing was affected. At all.
  15. The 65~200 ain't supposed to do that so....somewhere along the line it is damaged. If you like the lens it would probably be cheaper to find another sample than try to fix this one. Had one years ago, too big and heavy for me since it used it at 200 most all the time. Switched to a 200 f5 Zuiko, it's tiny and I don't mind the 2/3 stop loss.
  16. Please realize, this isn't your typical 'lightweight' Olympus Zuiko lens.
    It's in fact beefy, what with its 14 glass elements weighing in at almost 2lbs !
    Hitting the front of a long lens will bring about LEVERAGE forces to where it's mounted.

    Besides, who can say what the damage is until some technical inspection occurs (Like saying "hey I dropped my lens, or I crashed my Ferrari, what's wrong with it & how much to fix it?"

    Click on the image I provided and notice the condition of the rear shield. With the OP's unit, those two protecting prongs were in fact 'used'! Looks to me like they did their job in protecting the rear elements when confronted by an obvious trauma (without a doubt his zoom lens has been mistreated).

    Finally, I've tested after servicing many 80's era Zooms; this included Nikon & even Vivitar Series-One units. By far the best performers were #1 The Canon 'L' glass 80-200 FD, #2 The Carl Zeiss 80-200 Contax/Y and followed closely by #3 this Olympus 65-200.

    But beware, because of the age, the complex mechanism & its required lubrication, and the nature of having to move the groups in & out (inhaling/exhaling air), these zooms are all subject to severe out-gas lube fumes and mold/fungus...

    Canon 'L' - Olympus OM - Zeiss Contax

    Fantastic 80's era Zooms
    Last edited: Jun 15, 2018
  17. Thanks -- I'm always pleased to see Lens 'centerfolds' :)

    In the age of "drive by wire", these wonderful old mechanical solutions are fascinating == kind of like the Babbage engine (lINK).
  18. Yes, something is certainly wrong with it, and it may be due to being dropped or banged. Actually, I suppose it almost certainly is, because it's unlikely to be a manufacturing defect. But, I haven't even been able to use it, so I haven't had a chance to damage it.

    I tried looking through the back of the camera as I mounted a 50mm and the zoom, to see if I could spot the problem. I couldn't. Not all of the mount is visible, that way, and I'm not sure the cause would be visible, anyway.

    I was thinking that it might not be too difficult to replace the mount on the zoom with the mount from a donor lens. Has anyone here tried that before?

    Oh, and thanks for all the input! :)
  19. You can take a marking pen such as a sharpie and ink the areas of the mount you suspect are binding. Attach and twist the lens until it binds then remove lens and examine the mount where the ink has rubbed off. You'll get a good idea where the problem lies.
  20. Just a thought, if you are still trying to resolve this issue, if you have a slim extension tube/ring you could try mounting the lens to that. You should be able to see where the lens is binding, also if the worst happens and the lens becomes stuck or damages the tube then you have only damaged or lost a relatively cheap item rather than damaging your camera.

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