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Arfd
Tinkerer
Username: Arfd
Post Number: 14
Registered: 01-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 07, 2013 - 05:29 am: | 
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Has a member of the forum worked on Tamron zoom Model 103A? In its day this model had a good reputation but my one requires the moving optics to be accessed for cleaning. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 235
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 08, 2013 - 08:13 pm: |
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The Tamron 80-210 still has a very good reputation. It's seen a rebirth of interest by the many DSLR users who are now adding manual focus lenses to their inventory. But clean examples can still be picked up for reasonable sums, so if yours' condition is hopeless, at least you can pick up another for cheap.
I have a fungus-riddled Tamron 80-210 that I partially disassembled in an attempt to get at the fungus. In my lens's case, it was in the front group area. The problem I ran into is my lens spanner wasn't up to the job. The first retaining ring I encountered was extremely tight and my spanner just would not maintain a good grip. I did eventually get the ring off. It held in place a single thin element. Beneath that element lay the front group I suppose you'd call it. Another retaining ring holds this in place. And that was as far as I got. It was even tighter than the previous ring and my spanner was gouging out the slots, so I just called it quits. The lens was given to me anyway, so no loss for me.
I don't think it is normal for the retaining rings to be that tight. Given the amount of fungus in the lens's interior, I suspect it was stored in a humid location for years, and if this is the case, then perhaps there is some corrosion in the ring grooves also. I ddn't see any evidence of this, though. I tried using some naphtha as solvent on the threads to see if that would ease things, but it didn't make a difference.
So my advice: if you don't already have a stout lens spanner, get one before you take on this task. And if you have to tear into the lens further than the front group, just take your time, be patient, take pics of the disassembly as you go along. |
Arfd
Tinkerer
Username: Arfd
Post Number: 16
Registered: 01-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 18, 2013 - 05:10 pm: |
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Thanks for your advice, but I managed to open the lens quite easily by removing the outer focus tube, in my case there was no need to remove the front glass individually. My problem is removing and resetting the 2 zooming groups. This looks near to impossible without a detailed schematic. These diagrams must exist but I suspect professional repairers are keeping them close to their chest! |
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