Is this thing broken? (Zuiko 35)

[mrjr]

According to the focusing split prism in at least three Olympus OM bodies, my Zuiko 35mm f2.8 no longer focuses to infinity. What's going on, here?

Rotating the focus ring feels normal, and the hard stops at either end (minimum focus and infinity) feel normal. But upon looking through the viewfinder and attempting to focus on distinct verticals at a distance, the focusing ring stops before the images converge in the split prism. Likewise, the distance scale seems to indicate an incorrect distance (too far) compared to my intuition for subjects within, say, 10 feet.

I assumed that my OM-2n perhaps needed service, but my newly-acquired OM-2S exhibits the same behavior with this lens, and I don't see it when I put my Zuiko 50mm on either body.

Diagnostic help greatly appreciated.

 

[John Koehrer]

The focusing ring on the lens may have slipped a bit. I've seen this on other brand lenses.

 

[Arvee]

Something that just occurred with a lens you have had for a while or a new acquisition? If a new acquisition, perhaps someone has disassembled and didn't reassemble properly or added shims to fit a particular camera. Also, rear flange screws could have loosened and that would account for short focusing.

 

[KidA]

Something that just occurred with a lens you have had for a while or a new acquisition? If a new acquisition, perhaps someone has disassembled and didn't reassemble properly or added shims to fit a particular camera. Also, rear flange screws could have loosened and that would account for short focusing.

This is likely why.

 

[Xmas]

When you strip and reassemble you need to set the infinity setting at infinity like the moon on a reference SLR body.

If the photos are ok it won't matter.

Otherwise screwdriver set...

http://olympus.dementix.org/Hardware/

 

[theart]

It sounds like it was taken apart and reassembled with the helicoid started on the wrong thread. I always seem to need at least eight tries to catch the right one.

 

[Xmas]

Some lenses are indeed dependent on exact entry points of both inner and outer threads.

But most OM lenses are not instead infinity is three grub screws, I've forgotten about the OPs lens, too long ago.

You can tell from the engineering drawing in linked OM site.

 

[mrjr]

Something that just occurred with a lens you have had for a while or a new acquisition? If a new acquisition, perhaps someone has disassembled and didn't reassemble properly or added shims to fit a particular camera. Also, rear flange screws could have loosened and that would account for short focusing.

I've had the lens for some time, but I guess it's possible I received it this way and that I didn't notice it before.

I haven't taken it apart, and probably won't, although this would be a perfect opportunity to practice some repair skills. Definitely sounds like repair—or replacement—are in order.

 

[EdSawyer]

pretty sure I have a mint OM 35/2 I could part with, complete with hood and case, if you are interested in upgrading.

 

[mrjr]

pretty sure I have a mint OM 35/2 I could part with, complete with hood and case, if you are interested in upgrading.

Was I really that obvious about fishing for an excuse to upgrade?

But it's true... I've had my eye on the big brother for ages now. Just haven't been able to snare one for the right price.

 

[Arvee]

How serious is the error? If, for example, you set the lens to infinity and focus on, for instance, a vertical line and walk back and forth, what is the actual distance to the subject when in focus according to the split image?