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Message |
    
Robertofollia
Tinkerer
Username: Robertofollia
Post Number: 6
Registered: 04-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 13, 2007 - 04:50 pm: | 
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Hi all, I would need you input in how to tighten or find the set bolt/screw in the focusing ring of this lens. It's smooth but the focusing ring has developed some play, as if the bolt had come loose.
I've taken apart:
1.- The name plate: Nothing to be seen or bolts to be tightened.
2.- The mount: as above
3.- The focusing ring rubber: Nothing, either.
I would be very grateful if somebody could point me in the right direction, as this lens is very sharp and confortable in everyday use.
Thanks and best regards,
Robert |
Aaron
Tinkerer
Username: Aaron
Post Number: 19
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 13, 2007 - 09:11 pm: |
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My experience with the 50/1.9 lens is the front tube with the name plate can be unscrewed thus exposing the focusing ring. |
Robertofollia
Tinkerer
Username: Robertofollia
Post Number: 7
Registered: 04-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 18, 2007 - 02:10 am: |
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Hi Aaron,
I dismantled the front name plate but the only thing I saw were the threads fixing the front element. So then I must unscrew the whole front tube, with the element attached, in order to expose the focusing ring screws?
Thanks and best regards
Robert |
Glenn
Tinkerer
Username: Glenn
Post Number: 149
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 18, 2007 - 03:42 am: |
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Robert,
On some lenses the focus ring is threaded onto the rear part of focus mount. This thread is normally a single start, very fine pitch one. The focus ring in this set-up has the female multi-start helix cut into the inner diameter, the actual movable 'lens barrel' has the male multi-start helix cut on its outer diameter.
Thus any play that appears in the focusing ring on a lens with the above construction, is due to lack of grease in the fine threads. Depending on the actual mechanical construction, unscrewing the focus ring can be a simple matter of removing the stop-screws/keys, so that the complete optical unit can be removed before removing the focus ring limit screw.
Of course the above may not hold for your actual lens, I have not worked on the ML 50/1.9 and it does appear from Aaron's comments that the 'whole' front tube needs to be unscrewed. |
Robertofollia
Tinkerer
Username: Robertofollia
Post Number: 8
Registered: 04-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 18, 2007 - 01:13 pm: |
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Sorry, I explained myself bad. When I said play I meant the focusing ring moves freely, as if the set screw was loose. I mean, I move the focusing ring and after 1-2 mm the inner barrel starts moving. There is virually no play in the helical threads.
What I would like to do is fix the focusing ring so it has no longer this play and I can focus comfortably.
I'll try to take the front element apart tonight and post the results tomorrow.
Thanks and best regards
Robert |
Mikel
Tinkerer
Username: Mikel
Post Number: 27
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 18, 2007 - 03:57 pm: |
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Most of these Yashica 1.9s I've seen have the front element group encased in plastic as a unit. It is a tight friction fit into the barrel. If you unscrewed the complete name ring assembly you should see some screws underneath which attach the focusing ring to the outer helical. This is most likely the problem area. |
Aaron
Tinkerer
Username: Aaron
Post Number: 20
Registered: 10-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 18, 2007 - 07:55 pm: |
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Robert
Beware that the front tube is very tight when you try to unscrew it. You can then tighten the screws fixing the focussing ring.
Aaron |
Robertofollia
Tinkerer
Username: Robertofollia
Post Number: 9
Registered: 04-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 19, 2007 - 05:38 pm: |
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Itīs 1:30 am in the morning but... Iīve succeeded! That plastic tube is out, the bolts/screws (which were pretty loose by the way) have been tightened, everything has gone back in after cleaning and brushing out all the dirt and debris inside and the lens has recovered its initial smoothness. So THANK YOU all, specially Aaron, for your valuable help. Now my lens is operative again and waiting for my beloved Contax S2, which is out in Germany for a service (not bad after 13 years non stop ). Thanks again all you. Best regards. Robert |
