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Old Dec 29, 2007, 10:40 AM   #11
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jack,
it probably is. the tak300/4 was very similar, so was a vivitar200/3.5...as far as the ap ring if it's like the K/M50/1.7 i had that had a problem with the ring just turning around and around and not doing anything then it's a small lever.. you have to remove the mount and the actual ap ring(watch for the ball bearing falling out) ..
there's a small flat triangular piece that has the top flattened off that passes thru the barrel to engage the ap ring. this adjusts the actual ap ring. it only sticks out into a slot on thebarrel by maybe 1/64-1/40''. i had another lens to compare to..

roy
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Old Dec 29, 2007, 10:41 AM   #12
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i've got a 50/1.7 down now if you need more pix.

roy
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Old Dec 29, 2007, 12:02 PM   #13
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robar wrote:
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i've got a 50/1.7 down now if you need more pix.

roy
If you can give me a pic of the aperture mechanism, that could help a lot.
Only just got back home ... been out to a very short notice family gathering, and renewing acquaintance with a nephew and his wife on a flying visit from down under, several years since we last saw them. ... Jack
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Old Dec 29, 2007, 2:08 PM   #14
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A question: how do you get your workspace dustfree enough to dissasemble lenses? Or rather, to put them together again witout getting new dust inside?

Kjell
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Old Dec 29, 2007, 5:22 PM   #15
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jack,
what exactly is the lens doing. i'm not sure what the probs are.

kjell,
i do woodwork for a living. it's NEVER dust free.. i don't take something apart unless it's really necessary and hope for the best. what i do is have bottled air handy and blow everything off as i go along. most of the lenses are contained in modules so you end up with only 2 surfaces exposed. i've found the most dust comes from the cloth you are using to clean the lenses..

roy
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Old Dec 30, 2007, 5:27 AM   #16
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robar wrote:
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jack,
what exactly is the lens doing. i'm not sure what the probs are.
Roy,
This lens Pentax-M 135/3.5 came from a friend who has no Pentax gear now, he tells me that one day he was turning the aperture ring, and heard a loud click has he did so ... since then the focus ring only turns a small amount at the near end of it's range, and turning the aperture ring has no effect on the aperture itself which remains wide open. We think something has come adrift in the aperture mechanism, and this is fouling the focus ring, so as not to let it turn through it's full range.
I've had the mount off, and the aperture ring, but have been unable to strip it down further because I have only watchmakers screwdrivers, and can't get enough purchase with these to move 3 screws on the lens barrel. I need to find crosshead screwdrivers with bigger handles. ... Jack
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Old Dec 30, 2007, 5:30 AM   #17
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Duplicate post ... not sure how it happened.
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Old Dec 30, 2007, 10:00 AM   #18
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that's as far as you probably need to go. look on the inside of the ap ring. is the ree a vertical indentation about 1/8-1/4'' wide on it?? also , at this point you should be able to see if something is blocking the helicals from moveing. oh, you have to have the lens modules removed so you can see inside.

roy
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Old Dec 31, 2007, 6:25 AM   #19
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robar wrote:
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that's as far as you probably need to go. look on the inside of the ap ring. is the ree a vertical indentation about 1/8-1/4'' wide on it?? also , at this point you should be able to see if something is blocking the helicals from moveing. oh, you have to have the lens modules removed so you can see inside.

roy
Thanks Roy,
I'll give it another go when I find some suitable screwdrivers, preferably JIS standard if I can find them. ... Jack
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Old Jan 3, 2008, 9:21 AM   #20
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jachol wrote:
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robar wrote:
Quote:
jack,
what exactly is the lens doing. i'm not sure what the probs are.
Roy,
This lens Pentax-M 135/3.5 came from a friend who has no Pentax gear now, he tells me that one day he was turning the aperture ring, and heard a loud click has he did so ... since then the focus ring only turns a small amount at the near end of it's range, and turning the aperture ring has no effect on the aperture itself which remains wide open. We think something has come adrift in the aperture mechanism, and this is fouling the focus ring, so as not to let it turn through it's full range.
I've had the mount off, and the aperture ring, but have been unable to strip it down further because I have only watchmakers screwdrivers, and can't get enough purchase with these to move 3 screws on the lens barrel. I need to find crosshead screwdrivers with bigger handles. ... Jack
Hi All,
Pleased to report that after swapping a few e-mails with Roy, and my own dismantling efforts that the Pentax SMC-M 135/3.5 is now functioning normally. Problem was that a link had come disengaged from a fork in the auto-stop down mechanism, I think due to some sloppiness in ASD lever itself, a bit of judicious tweaking seems to have sorted that out. I have it all recorded photographically if anyone ever need the info.
OE I hope you're having similar sucess with your project. ... Jack.
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