How to disassemble and clean Zuiko 85mm f/2

Hi,

 

There's quite some dust particles in my Zuiko 85mm lens. I believe it's on the

surfaces in front of and behind the diaphragm, because that is the only place

where dust can get - through the diaphragm mechanism.

 

I was able to unscrew the 2 blocks: the rear (focusing ring), and the front

(optical block), but I don't know how to get to the aperture. There is the

mechanism of the rear floating group... and I think if I could remove the rear

group with its mechanism, I could clean the dust in there...

 

 

Please, I'd like to know how to get to the aperture. Do I have to go through the

front? Or can I just somehow remove the rear group? Please help.

 

PS: exploded diagrams don't say much :(

BTW I also posted this question (with a couple of pictures!) to KYphoto camera repair forum <a href="http://www.kyphoto.com/classics/forum/messages/2/8525.html?1168951276">here</a>

Excuse me, <a href="http://www.kyphoto.com/classics/forum/messages/2/8525.html?1168951276">here</a> is the good link :)

I've never worked on the 85mm, but I would expect that you would reach the diaphragm through the front. But you say you removed the front cell and did not reach the diaphragm?

I would have left it alone if it's just dust. Many lenses require extremely precise alignment

during assembly, and if you are even a millimeter off in a crucial part of the reassembly

process you may as well throw it away.

 

Dust will not show up in photographs unless there is a ton of it.

No Rick, I went through the rear. I removed the bayonet, then unscrewed the focusing helical to clean it and replace the grease (white lithium with PTFE). I think the grease a bit too thick...

 

And I know that dust won't show on photos... I just like to have my equipment in 110% shape, and the dust just won't let me sleep ;)

 

OTOH I would sleep even worse if I messed it up, so I'll let it be for now.

It would be a shame to ruin a beautiful lens for the sake of one's comfort. I think you made

the right decision.

I have a single speck on one of the inner elements of my 100/2. It drives me crazy when I hold the lens up to the light.

 

I long ago wanted to have it cleaned, but it's just not worth the risk of damage, not to mention the cost.

 

Because it is towards the barrel, rather than the center, I tell myself that that part of the glass won't even be used at middle and small apertures. (And that might even be true, as well...)