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11-06-2009, 12:24 PM   #16
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Ressurection of this thread....

I've got a similar lens as the OP, Vivitar 28/2 MC wide angle N0. 22xxxxxxx. The aperture blades are a little oiled, and it causes a slooowwwww mooooowtiooon when closed. So, effectively, the aperture won't close on the camera!
Tried SoldBears jar-trick, but the lens did not open. The front element can be turned (about the distance the word "feet" takes), but it doesn't come off. Any suggestions? Do I have to use more force? Am I doing something wrong?

11-07-2009, 11:50 AM   #17
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Nobody? .
11-07-2009, 11:55 AM   #18
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QuoteOriginally posted by Rense Quote
Nobody? .
Some of the earlier posts already mentioned the force it took to separate the two parts of the lens.

Why don't you post a photo of the lens? It may or may not be the lens I know.
11-08-2009, 04:15 AM   #19
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QuoteOriginally posted by SOldBear Quote
Some of the earlier posts already mentioned the force it took to separate the two parts of the lens.

Why don't you post a photo of the lens? It may or may not be the lens I know.
Yes, I think is my half-English that bothers me here

I will post a photo later on this day.... Thanks in advance!

11-08-2009, 11:15 AM   #20
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Two photos of the mentioned lens. I can move the front element, but after a cm or so I can't get it further. It's not going stiffer, it feels as if a pal or something runs to the end of a notch. I hope this makes sense to you native English speakers ?



11-14-2009, 02:36 PM   #21
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SOldBear, PM'd you
11-14-2009, 02:53 PM   #22
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How you guys work this out and save a nice lens!
11-14-2009, 03:00 PM   #23
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QuoteOriginally posted by rparmar Quote
How you guys work this out and save a nice lens!
Yeah, well, it's because of you I bought this one

11-15-2009, 01:08 PM   #24
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Not "how" -- I meant to say "hope". Doh!
11-16-2009, 04:52 PM   #25
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QuoteOriginally posted by Rense Quote
I can move the front element, but after a cm or so I can't get it further. It's not going stiffer, it feels as if a pal or something runs to the end of a notch. I hope this makes sense to you native English speakers ?
Your English makes perfect sense (I'm not a native English speaker/writer).

But the symptom puzzles me. The lens in the photos you posted does look like the ones I worked on. But I don't understand as why you can't separate the front and rear parts of the lens.

I have another question: when you turn the focus ring of the lens, does the front of the lens rotate too?

If the answer is "yes," it is definitely the lens I recently repaired (then sold). Try to twist the front part of the lens harder.
11-22-2009, 08:40 AM   #26
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QuoteOriginally posted by SOldBear Quote
Your English makes perfect sense (I'm not a native English speaker/writer).

But the symptom puzzles me. The lens in the photos you posted does look like the ones I worked on. But I don't understand as why you can't separate the front and rear parts of the lens.

I have another question: when you turn the focus ring of the lens, does the front of the lens rotate too?

If the answer is "yes," it is definitely the lens I recently repaired (then sold). Try to twist the front part of the lens harder.
SOldBear, the answer is "NO"! Turning the focus ring doesn't affect the front element (exept for moving forwards, of course).
So, probably it's not the lens you worked on and I have to try it another way???
11-22-2009, 07:24 PM   #27
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Kiron made two different versions of this lens. The picture below shows three different lenses. The lens on the left is the Kiron branded 28 F2.0. The center is the Vivitar version of the same lens. These lenses are identical except for the branding. The filter does not rotate when the lens is focused.



The lens on the right is much different. The filter does rotate when focused, it is slightly larger and heavier, and the focus throw is much longer. The Kiron and the center lens both focus from infinity to close focus in about a third of a turn. The lens on the right takes about three quarters of a turn. All three focus to 0.3 Meters close focus.

The Vivitar lens in the center is like the one you have. I have completely disassembled the lens and the aperture mechanism to clean oil off of the blades. This job is not for the faint of heart. The most difficult part is that the focusing helices have to be put together in exactly the same orientation that they are disassembled from. This took a lot of time making measurements and notes to get it back together in exactly the same position. There are two different helixes that move in diffent directions at different rates - I think that this is called a floating lens design.

Anyway - I did not just unscrew the front of the lens - it is not that easy. I found a person posted how to disassemble this exact lens and I followed his directions.

CLA Kiron 28 f/2 part #4/4 on Flickr - Photo Sharing!

The only caution I would say is that removing the aperture mechanism, do not use the marking method he shows - it will not work. You must mark different places to be able to assemble in the same postion.
11-23-2009, 10:46 AM   #28
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Thanks Pentaxman! I know the link you provided, and I hoped my lens would not be that somehow difficult one . Well, I will set apart a Saturday and spend some hours on this one...! Thanks again!
12-05-2009, 06:43 AM   #29
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QuoteOriginally posted by Rense Quote
Thanks Pentaxman! I know the link you provided, and I hoped my lens would not be that somehow difficult one . Well, I will set apart a Saturday and spend some hours on this one...! Thanks again!
Did you ever get this sorted out. I have picked up a Kiron 20mm F2 optically perfect for $5, with the same problem, and it also does not seem to want to open up, even though my vivitar 24F2 was no problem, just really tight.
12-05-2009, 02:44 PM   #30
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just a quick note,

I got my Kiron 28mm F2 apart.

It has a thread locker to insure that the front group does not come off.

I used a strap wrench to take it off. only takes a few seconds to do, and then it is easy to clean the blades.
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