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01-16-2017, 09:51 AM   #1
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SMC Takumar 135mm f/2.5 (6 element version) disassembly question

Does anybody have experience disassembling this lens? Specifically, I would like to gain access to the inside of the front element to clean off some fungus. Is it as simple as taking off a retaining ring in the front and popping it out or would I need to start back at the mount?


01-16-2017, 10:13 AM   #2
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Thanks for the quick response, if you are able to confirm that would be wonderful.

I'm not sure that I would trust myself to do what you're describing (taking apart the barrel and removing the whole front group) without damaging it.
01-16-2017, 10:20 AM   #3
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The front barrel unscrews so step one is really easy - focus to 5 feet, hold the focus grip in one hand and unscrew the protruding barrel with the other. That lump has the front four elements so you may have more work ahead. I think dcshooter is right, the next step is to start from the back of that assembly and work forward.

Let's see if this picture still works. It's the K version with the front unscrewed but construction is the same.
01-16-2017, 03:19 PM   #4

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I found it almost impossible to get to the element just in front of the aperture blades when I was cleaning my K135/2.5. It really didn't seem to want to open. The front element group unscrews really easily on that one, as does the rear group with a tool. The middle elements are a pain though.

01-16-2017, 03:57 PM   #5
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Thanks everybody.
03-14-2017, 02:41 PM   #6
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Finally getting around to this...

Taking advantage of the snow day here in Boston today, I've finally started to open this lens up. I unscrewed the front part of the barrel and started working at the glass in that piece from the rear as recommended. The first element came out without much issue. The second one....has no retainer ring in back and looks like it needs to come out the front instead?

I tried to remove the front retaining ring (name plate) but it's stuck and I'm afraid to really torque down on it. I've got it in a heating pad right now in the hopes that it will loosen up any adhesive that may be working against me.

Any other tips? Am I missing something?

Thanks again!

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