    
Gregg_macpherson
Tinkerer
Username: Gregg_macpherson
Post Number: 4
Registered: 04-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 20, 2012 - 05:54 am: | 
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I just realized that these lenses were made in the 80s I think so may be not a legitimate subject. But some of the classic lens repair guys will have worked on these, so here goes.
I'm looking at some (S16) Zeiss MK II distagons. Ex German TV, quite cheap, optically quite clean and looking good through the viewfinder and hitting the focus marks. But on a couple of them there is some mechanical wear or loosness in the focus ring or what I assume are cams inside. I will show them to a good lens tech in a few days, but I'm really curious to get some ideas about it.
The 12mm has what feels to the fingers like a fraction of a mm backlash in the focus ring. The little thud that you feel at either end of this is quite distict. The grease is fairly viscous so it's hard to tell if there is inertia involved or not. Like maybe something heavy is being rotated over that fraction of a degree.
The 25mm has what feels like a very loose focus ring. If you look at the edge of the focus ring you see almost a mm of completely free backlash in the focus movement (about 3/4 of a degree). You can wiggle the focus ring about the vertical and horizontal axis so you see over a mm of movement at the edge (a bit over a degree)
Both these lenses look fine through the viewfinder while working the focus ring. You could actually use them just like that.
Any thoughts? Cheers,
Gregg. |
