Zuiko 50mm f1.8 and Oly OM10

angelus · Joined: 15 May 2011 Posts: 29

Hey guys, two things are bothering me, and I hope you can help me.

1. I have zuiko 50mm f1.8 "Japan" that has oil on blades, and some other problems. So, I found few "made in Japan" that has fungus on glass, but everything else works well. If I buy these cheep "MIJ" with fungus, can I replace the glass only, will it fit from "japan" to "made in japan"?

2. If anyone of you have asa dialer brushes, and doesn't need it, I need one to fix my OM10, you can PM me, or reply here. Thanks

Ymmot · Joined: 24 Sep 2011 Posts: 168

you can check using the exploded view here, however as far as I know the internal construction of the lens has changed over the versions, so I do not know if it is possible.
http://olympus.dementix.org/Hardware/olympus_hw.html

Also your 50mm, do you see the oil on the blades or are they only slow?
My (limited) experience is that zuiko's are succeptible to sticky aperture, however at least in all my lenses with this problem, this is only the mechanism behind the mount, not the actual aperture blades (and for me it was easily fixed).
It seems that the oil from the helicoid sometimes migrates to this portion of the lens.
So if you remove the mount by unscrewing the 3 screws on the back you can get to the mechanism.
If it is greasy or sticky this is likely the problem (even if the grease is very liquid it is a problem).
Clean al the grease such that it is dry and operates smoothly (no damping when the aperture mechanism is reset by the springs inside, everything should shoot back without hesitation or slowing after operating the mechanism with the lever on the back and the DOF button).
Finally put it back together as you took it apart and it should be OK (make sure the prongs going to the aperture ring and aperture itself are put back in the correctly).

angelus · Joined: 15 May 2011 Posts: 29

Thx Ymmot, I tried to fix the lens with cleaning, but no success.
In that cleaning, from few days ago, some little thin "spring" came off, and I don't know how to put it back :s

I guess the best thing would be to buy another one, working one.

Attila · Expire: 2025-11-18

general rule for lens fixing to use marker to mark parts before screw them off and camera to snapshot genuine positions until you get experience , marking very important even if you are over on hundred of items. Next one will be more successful, don't give up.

Sometimes tragedy can happen in diy fixing, my last ruined items was a Biometar 80 I couldn't mark positions and lens got unsharp at infinity Sad

had to put into pro hands to restore it Laughing

Another one I did kill a camera with 3 hrs fixing, nothing did work after Sad

I still shame my self on both cases...

angelus · Joined: 15 May 2011 Posts: 29

Ymmot · Joined: 24 Sep 2011 Posts: 168

If you have some photographs, I can try to help to put it back together (assuming you still have the spring).
(please also one of the front of the lens, may matter to determine the version of the exploded parts diagram).

Is it a normal (linear not rotational) spring with two eyes at each end?
If so it is likely the return spring for the stop down pin.
I can try to give some guidance for that (for the MC version of the lens).
This is what I can see from the exploded parts diagram and remember from an other zuiko lens that has a similar construction.
In case the lens is face/front down, with the mount removed.
Likely you are now seeing two rings on top of each other, which are the ring for aperture stop down and aperture coupling, with underneath the two a plate.
Likely the top ring has a part that goes through the mount for stopdown of the aperture, but also a small second tab that does not. This tab is one of the mounting points for the spring so put one of the eyes of the spring over that.
next examine the plate underneath both rings. It will also likely have a similar tab to that on the ring. Use something like a crochet hook to get the eye of other end of the spring, and put the eye over the tab on the plate.
Make sure that the two tabs are as close as possible to eachother (aperture should be wide open).
Now you should be good and the lens can be reassembled (if nothing underneath the plate is giving trouble when reassembling, it may be a bit fidly then as there is a spring loaded component that works the aperture stopdown button on the lens there).

angelus · Joined: 15 May 2011 Posts: 29

Ymmot · Joined: 24 Sep 2011 Posts: 168

Mmm

, I've never had to disassemble any lens this far (yet), I guess I was lucky before...
Also it strikes me as an odd part to come loose and drop out of the back after removing the rear mount though, as if someone has opened it before?
I would expect it to remain in the front of the lens if it comes loose judging by its original location?

I did find this step by step disassembly/cleaning guide for this lens though (you may have found this already):
http://olympus.dementix.org/Hardware/50mm_cleaning.html
Oddly it never mentions the spring even once, so I can't really say how it should be put back exactly Sad

.

It seems that you don't really need a rubber friction tool though, there are two indents for a spanner wrench hidden between the ridge of the front ring with the text and the filter tread (a bit hard to see).

angelus · Joined: 15 May 2011 Posts: 29

folke_k · Joined: 07 Dec 2012 Posts: 2 Location: sweden

trying to fix the lens is worth a little work. Japan lenses are not really the same as made MIJ lenses. They have different coating.

But why bothering with an OM10? unless it is a rare black one, you probably find some for 10 Euro or 10 dollar. They are not really appreciated by collectors and were sold in huge amounts.