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Re: [OM] Back from Enduro India - OM 35-80/2.8 paid the priceand is stuc

Subject: Re: [OM] Back from Enduro India - OM 35-80/2.8 paid the priceand is stuck on F8
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Mon, 21 Feb 2011 17:58:28 -0500
 From the parts PDF it appears there is a small spring and detent ball 
that presses on the back side of the ring towards the lens mount.  When 
you pull back on the ring you are compressing the spring and probably 
compensating for dirt and/or lack of lube.

You can get a copy of the PDF from Mark Dapoz's site here:
<http://olympus.dementia.org/Hardware/PDFs/35-80mm_f2.8.pdf>

See the first page and the third ring from the right in the top row. 
The second ring is the aperture ring.  Note spring part number CA071500 
which is recessed into the third ring and what I assume is the detent 
ball, part number WE201036 which presses on the back side of the 
aperture ring.

If I had to guess I'd say it probably just needs to be cleaned and given 
a teeny dab of grease so the ball can slide smoothly on the backside of 
the ring.  My 28/2.8 had a similar problem and wouldn't open wider than 
f/5.6.  Cleaning followed by that teeny dab of grease worked miracles.

Chuck Norcutt


On 2/21/2011 4:43 PM, SwissPace wrote:
> I haven't yet been brave enough to remove the rear mount yet, but after
> more inspection I discovered that the aperture adjust ring has play
> front to back and that if I slide it back towards the camera I can turn
> the aperture ring and then when it "springs" forward again it locks the
> ring again. I assume is not some new feature I have found but it seems
> to be quite useful :-)  but more likely a bearing that has come out
> although the good news is It seems that it hasn't affected the sharpness
> of the lens as you can see in this image from this weekend.
>
> <http://thattimeoflife.smugmug.com/Portfolio/2011-Few-Fotos-For-Fun/15910940_2Y2hT#1194515466_BuWA5-L-LB>
>
> Is it tricky to work out where the bearing should go?
>
> Thanks
>
> IanW
>
>
> On 2/18/11 7:50 AM, |-o-| wrote:
>>>> . . . however the biggest casualty was my 35-80/2.8 which seems to be
>> stuck on F8, I think the rear cap came off and maybe something got twisted
>> as it bounced in my camera bag.
>>
>>> Unless the 35-80 is greatly different from other OM lenses, there's a fairly
>> simply part of the mechanism directly under
>>> the mount. The area isn't particularly well sealed, so dust, dirt, etc. 
>>> could
>> get in. Also, a couple of parts are fairly
>>> flimsy. I've fixed 2-3 sticky apertures simply by working there.
>> WATCH OUT for bearings dropping out.
>>
>> As Moose offers, look under the mount first. The aperture ring for that
>> lense also uses a couple (or more ?) bearings. I had to dismantle my old
>> 35-80 once when the bearing came out of the track due to loose mount
>> screws, once I got the bearing back in the right spot the Aperture worked
>> fine again, and didnt wobble between the front and rear of the lens.
>>
>> Cheers
>> Ian Manners
>> Power corrupts...Absolute Power is kinda neat...
>
-- 
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