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Bill Salati
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 27, 2004 - 10:26 pm: | 
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I need some suggestions on dealing with rust and thread locking compounds.
I've taken this lens apart again and gotten a bit further. Screws that secure the iris mechanism are accessed through holes in the lens body. The focus ring has to be removed to reach these. This procedure conflicts with Henry Taber's article on this site, so maybe our lenses are from different production runs.
Removing the screws from the front of the iris assembly allows disassembly for cleaning. I discovered this by accident as I thought these were the screws Henry referred to for removing he unit.
Scribe a reference mark from the mechanism cover to the lens body before removing it. Scribe another mark to keep the front and back halves of the iris unit in the same orientation. I failed to do this and face a lot of trial and error reassembly to get the f - stops calibrated!
The mount section is still jammed up tight and soaking in WD-40. Since the lens is water damaged I am assuming the bazillion, itty bitty balls have rusted, causing the jam. It's a Canon FD mount and has two or three times as many itty bitty balls as other mounts. The Minolta MD version of this lens has about half a bazillion.
I am still trying to loosen the set screw that secures the front and second group together. There is evidence of water here, too. The screw shows some rust and the back of the front element needs cleaning.
This seems to be a very well made lens. I've found no plastic in it, so far. All of the threaded points show thread lock compound!! The only detail I might consider a shortcoming is the all aluminum helicoid instead of the more traditional aluminum - brass - aluminum helical construction. |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 28, 2004 - 09:48 am: |
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Yeah Bill, I did that same thing on my iris assembly and had to re-calibrate too. Gives meaning to the name "f-stop"...
It is very possible we have different configuration lenses...perhaps a FL to FD difference.
Thanks for the added info.
Henry |
Bill Salati
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 28, 2004 - 01:16 pm: |
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I think all Kiron Canon mount lenses were the FD variety, Henry. The FD system debuted in 1971 and Kino began marketing as Kiron in 1980-81. I can vouch for different production runs in the 28/2. I bought one new in '81. It has a chrome breech lock ring and a "bazillion itty bitty ball bearings" in the mount. About a year ago I acquired one with a black breech lock ring (and sluggish diaphragm!). It does not have a "bazillion itty bitty ball bearings" in the mount. The two most recent Kirons are the water damaged 28/2.8 I am struggling with and a 28/2 in Minolta MD mount. The latter had a sluggish diaphragm, loose front element and sloppy helical. It seems all better now. There are some significant differences in the main body between M/MD and C/FD versions. If i get around to any others I imagine they'll be similar to the Minolta mount version. It's been an interesting pursuit! |
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