Olympus-OM
[Top] [All Lists]

Re: [OM] Tinkering with a f1.8 Zuiko

Subject: Re: [OM] Tinkering with a f1.8 Zuiko
From: Moose <olymoose@xxxxxxxxx>
Date: Thu, 19 Nov 2009 12:41:32 -0800
NSURIT@xxxxxxx wrote:
> If I have something worth fixing it goes to Camtech, however I just received 
> a 50mm f1.8 and the aperture blades will not move on at all and also a 28mm 
> f2.8 that has slow aperture blades.  Neither of these are lens upon which I 
> would pay to have a CLA.  Any words of advice from those who have traveled 
> this road about traps to be aware of when opening these guys up? What method 
> works best for getting the blades cleaned and working.  I might mention the 
> the 28mm doesn't appear to have any oil on the blades.  They  are just really 
> slow.  Bill Barber
>   

The first place to look is always under the mount, especially for lenses 
other than the 50/1.8. The DOF mechanism is pretty simple and 
straightforward, but it can get dirty, a plastic pin in a few models can 
distort or break, etc. It's also easy to move it and watch whether it is 
what's slow or the aperture mechanism deep inside.

You can easily remove the rings and springs and operate the aperture 
with a small screwdriver or other probe. If the problem is indeed 
inside, on the 50 and probably on the 28, you go in from the front. 
although the name ring probably has notches for a whatsitcalled spanner, 
and I've been able to open them that way, I gather that a rubber stopper 
using simple push hard and twist may be better. Apparently bathtub 
stoppers fit some smaller lenses well, or one can go with one from a lab 
supply house or the on line camera repair supply place.

Specifically as to the 50/1.8, the problem of oil on the blades and in 
the mechanism is particularly prevalent in the ones marked "MC", 
although I had one "miJ" with a modest problem. In the MCs, cleaning the 
blades alone may be only a temporary solution. I suspect the only long 
term solution is to clean the whole mechanism, removing and replacing 
the helix grease. Still, the simple cleaning is pretty quick and easy, 
and may be repeated.

Moose

-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz