[PhotoJoseph]

Hey there! New here; someone on twitter directed me. I have an Auto-Takumar 85mm /1.8 which according to this page on these forums has a 55mm front filter thread. Thing is, I can't get a filter to screw in. It does seem like the right size, and the threads don't even seem damaged —*it just seems like the thread ring is so shallow that it's not even designed to hold a filter! I'm wondering if anyone here has experience with this lens and can verify that it does in fact work so mine must just be damaged, or if in fact filters just won't go on here (weird). I'm considering super-gluing a step-up ring on there!

photo attached so you can see what it looks like.

Thanks!
-Joseph

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[BigMackCam]

Welcome to the forums

It's difficult to tell from the photo, but I wonder if the trim ring at the front has been removed at some point (perhaps for lens cleaning and/or servicing), and not fully screwed back. It looks as if that might be the case. Can you tell if there's a noticeable gap between the base of the trim ring and the glass?

[c.a.m]

I wonder if the trim ring at the front has been removed at some point (perhaps for lens cleaning and/or servicing), and not fully screwed back.

I am thinking the same thing.

@PhotoJoseph, welcome to Pentax Forums!

Is the name ring loose? Can you rotate it in either direction? It's possible that the ring was removed, then misaligned upon refitting, or it became misaligned upon removal. It might be jammed in the fine threads.

For now, may I suggest not super-gluing a step-up ring? That approach might afford a short-term solution, but would seriously degrade the quality (and value) of this excellent vintage lens.

- Craig

[Not a Number]

I concur with both above. An easy way to screw the ring down is to put on some rubber glove to give traction and use your thumbs to screw it down. Take care the front lens and gloves are spotlessly clean (not grit or dirt) and try to touch the lens element at little as possible to avoid scratching. It doesn't need to be tightened down very much.

[Bob 256]

Don't think the OP has an issue with a loose lens retaining ring - just the missing filter thread. I concur with the above replies otherwise (especially on not gluing an adapter in place). You might be able to find a machine shop who could machine you a short extension which would accept filter threads (internal). You might also have to show them a filter so they know what thread to use and how best to cut it. They would need to determine the thread that exists and it shouldn't be too much trouble from there. Have them make it out of brass and then polish&blacken it, and the lens would look great.

[PhotoJoseph]

Wow so many great responses so quickly, thanks guys! Great forum! I don’t have my hands on the lens now so I’ll get back to you all soon as I can. I won’t glue it; I promise. A 3D printer has reached out and wants to design a friction-hold ring that will add a 67mm thread (which is what my goal is). But as soon as I can I’ll check the suggestions here. Thanks again!

[PhotoJoseph]

An update…*someone sent me a video on twitter of doing precisely what was recommended here; tightening the ring with the writing on it. Unfortunately I can't get that to turn (in or out), so for the moment I'm on standby waiting for the 3D printed solution that's en-route to me. I'll continue to update!

-Joseph