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Message |
    
Gez
Tinkerer
Username: Gez
Post Number: 11
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 26, 2007 - 06:20 pm: | 
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I have recently been given a Konica 50mm 1.7 lens, the compact variety made about 1981. The glass is in great condition but the focussing ring doesn't move the lens barrel, it just turns aimlessly. There is evidence of past tampering so I tried to access the interior by removing the name ring, however it is not functioning as a retaining ring as there are no accessible parts under it! Does anyone have info on the construction of this Hexanon version? If possible I would like to get it working. |
Reborn7
Tinkerer
Username: Reborn7
Post Number: 1
Registered: 11-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 27, 2007 - 01:34 pm: |
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Hi,
I have exactly the same problem with my Hexanon AR 50mm 1.7 lens, although there are no visible tampering signs, the focusing ring is disconnected from the focusing mechanism ?? |
Reborn7
Tinkerer
Username: Reborn7
Post Number: 3
Registered: 11-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 08:33 am: |
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I tried opening the backside of the lens, removing 4 screws and the mounting ring.
But too scared to break something without any advice !
This how it looks now, anybody for help ?
 |
Nikos
Tinkerer
Username: Nikos
Post Number: 32
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 10:49 am: |
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I have never worked on a Konica lens but it is highly likely that there are set screws under the rubber grip of the focusing ring. Removing the rubber grip will expose them. Make sure you have the right screwdriver when tightening them. You start by reinstalling the mount of the lens.
Let us know if my guess is correct.
Nikos |
M_currie
Tinkerer
Username: M_currie
Post Number: 91
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 01:43 pm: |
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I just looked at my 1.7, possibly a little older than some, original to T3. The rubber grip is missing, and there are no screws! It's a mystery, but it looks as if the front edge of the focusing ring might be pressed on, and I wonder if there's something hiding behind there. It's hard to see whether or not that is a separate piece, and I don't want to pry on mine, but there's nothing showing on the exterior of the focusing ring. |
Hovaness
Tinkerer
Username: Hovaness
Post Number: 51
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 08:39 pm: |
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It sounds like the lens was disassembled and never properly reassembled. You are going to have to take it apart and make careful notes on each step. It helps to take digital photos of each step of disassembly. These lenses are beautifully made and can be restored to excellent condition. Just be patient, and remember to note and mark the positions of all important parts. |
Nikos
Tinkerer
Username: Nikos
Post Number: 33
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 02:54 am: |
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Taking the whole thing blindly apart entails the possibility of losing the use of the lens even as a paperweight. Your approach should be focused, especially since neither of you have any previous experience. Just try to figure out how to remove the "free wheeling" focusing ring. It is obvious that it will come out either through the front or the rear of the lens; usually the front. The most important aspect of disassembly is figuring out what is the function of the small part about to be removed. You will also need a good set of screwdrivers. |
Hovaness
Tinkerer
Username: Hovaness
Post Number: 55
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 03, 2007 - 08:43 pm: |
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The most critical step in disassembling this type of lens is to mark the engagement point of the helical threads. Because the helicals have multiple start points, failure to mark the correct engagement point will require a time-consuming trial-and-error process of discovering the thread alignment that results in correct back focus.
As you unscrew the helicals, carefully mark where the assemblies come apart, so that you can engage the threads at the same point when you reassemble the focus mount. |
Reborn7
Tinkerer
Username: Reborn7
Post Number: 4
Registered: 11-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 09:18 am: |
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My "new" lens was never disassembled and probably never been used (I wonder how this lens passed quality inspection !)
I have camera disassembly experience and I'm aware of the precautions needed for this job, but I never had to disassemble a lens and I cannot find out how to start :-( |
Nikos
Tinkerer
Username: Nikos
Post Number: 35
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 06:31 pm: |
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Just be a bit patient. My Konica 50mm 1.7 is arriving shortly so pretty soon you will have the whole story.
Nikos |
Nikos
Tinkerer
Username: Nikos
Post Number: 37
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 10:37 am: |
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Well, I am the proud owner of a Konica Hexanon AR 50mm F1.7 lens. I couldn't remember what the original problem was until I tried the focusing ring. Yes, you guessed right; it revolves but it does nothing. Now, I tried pinching the focusing ring and lo and behold the lens focuses nicely. So, after AF and MF lenses we have now a new category: PF lenses (not to be confused with the old Rokkors). Mystery solved; the lens was designed for Pinch Focusing.
By eyeballing this lens it seems that modifying it for Manual Focusing will be a pretty easy task. I will keep you posted.
Nikos |
Nikos
Tinkerer
Username: Nikos
Post Number: 38
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 11:31 am: |
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1. Remove (slotted) name ring using spanner or friction tool. This will expose the flange of the filter ring. You will see three set screws. They secure the filter ring in place.
2. Loosen said screws.
3. Unscrew and remove the filter ring. You will see three slotted screws that are loose.
4. "Focus" the lens to infinity or to its closest focusing point. Index the focusing ring and tighten the above screws.
Put everything back together and you are set for Manual Focusing.
I have taken photos if needed.
Nikos |
Nikos
Tinkerer
Username: Nikos
Post Number: 39
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 11:33 am: |
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I forgot. Air travel can loosen screws that are not secured with glue of some kind. |
Gez
Tinkerer
Username: Gez
Post Number: 15
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 02:52 pm: |
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Nikos, thanks for your efforts but my version of the 50/1.7 doesn't have an accessible filter-ring. However, I have been able to gain access by removing the 4 mount screws and lifting the chrome mount followed by the alloy ring containing the ball bearing race. Looking inside the lens I could see that a small brass tab that is held in a focussing guide slot had jumped the the slot. One of the screws had come out, even though locking varnish had been applied to its head. It was a simple matter to push the tab back into the slot and resecure the screw. The infinity position is set, the only difficulty now is to correctly reposition the aperture linkage. There is also a ball bearing providing a click-stop for the AE setting.
Indeed, how did this lens get through QC!!
It seems your version of the 1.7 is the well engineered 1970's heavy weight.
Reborn7, your example seems identical to mine. |
Nikos
Tinkerer
Username: Nikos
Post Number: 40
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 04:24 pm: |
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Gez, our lenses could not focus for entirely different reasons. In my case the focusing ring was not attached to anything. In your case the focusing mechanism proper was inoperative.
Reborn7 I wander what type of problem you have. Number one or number two, although the latter should be a rather rare occurrence. In number one by turning the focusing ring absolutely nothing should happen. In number two the lens should rotate.
Gez and Reborn7: It is obvious that my lens is somewhat different from yours. Could you possibly post a photo of the front of the lens?
Thanks,
Nikos |
Nikos
Tinkerer
Username: Nikos
Post Number: 41
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 07, 2007 - 07:11 pm: |
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It should be "Reborn7 I wonder"... |
Gez
Tinkerer
Username: Gez
Post Number: 16
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 08, 2007 - 01:06 pm: |
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Nikos, thanks for your feed-back, unfortunately, can't send a photo as I don't have a digital camera!
The problem isn't completely fixed yet as the infinity setting is not right. Will now try to access the helicoid. |
Reborn7
Tinkerer
Username: Reborn7
Post Number: 5
Registered: 11-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 08, 2007 - 04:15 pm: |
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Hi, will try to remove the alloy ring containing the ball bearing race, and hope to find that small brass tab that is held in a focussing guide slot...
It seems that Gez and I have the same type of lens !
 |
Gez
Tinkerer
Username: Gez
Post Number: 17
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 10, 2007 - 04:26 pm: |
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Reborn7. A small correction; the chrome mount contains the ball bearing race held by a retaining ring, so there is no danger of spilling them. The black alloy ring can be lifted straight off the main body, but it is best to keep the mount and the alloy ring together as the AE click-stop button will fall out. |
Gez
Tinkerer
Username: Gez
Post Number: 18
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 29, 2008 - 09:36 am: |
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Well, I spoke too soon, although the focusing guide is now working, the focus collar is back to turning aimlessly! It appears to be disengaged from the helicoid. Has anybody ventured further into this compact version of the 50mm 1.7?? |
Konicakrazy
Tinkerer
Username: Konicakrazy
Post Number: 2
Registered: 12-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, February 19, 2008 - 02:54 pm: |
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Just bought a Hexanon 50mm 1.4 lens which could not focus. read previous posts, especially from Nikos. Could turn focus ring but nothing happened. The answer was easier than I thought. Removed rubber collar, set to infinity, remove 3 screws thru access holes under collar, slipped off focus tube, removed name ring using rubber, removed front lens element using rubber, between aluminum tube and outside shell could just make out 3 screws. They were loose, tightened them and locked with glue and VOILA, lens focuses just like new. "CAUTION", not the screws holding shutter blades in place, (tighten those, and shutter gets stuck) but the ones between outside barrels. See many reports on non-focusing hexanon lenses, so it must be quite common. |
