Straightening lens filter thread

[monopix]

How do you fix bent filter threads on lenses?

I know you can get (expensive) tools to do it (like this one)but for the odd occasion I need to do it, I can't justify the cost.

So what do you guys use?

 

[coelacanth]

Unless you know someone who can fix it professionally (having that tool) and do it cheaper than the tool, that tool is your best bet I believe.

I don't have experience with filter thread repair, but from my motorcycle/bicycle wrenching experiences, I'd say this: don't force anything without knowing exactly what you are doing. I can't stress "exactly" part enough. Threads are bxxxxxx.

 

[kermaier]

I had a Nikkor 50/1.4 LTM with a messed up filter ring. Essex camera didn't sound too confident of their ability to fix it (uncharacteristic for them), so I sent it to DAG who fixed it quickly and cheaply. Much depends on how badly deformed the front rim of the lens is, vs. how badly crushed the threads are.

 

[oftheherd]

I once straightened out a Yashica 50 f/1.7 filter ring with large wooden dowels from a hardware store (some hobby stores carry them too). Cut off a small piece, round one end with a rasp or file, and gently tap it back into place. You must be careful, and the outside of the ring should be braced. Flatening another piece of dowel, then rasping out a concave shape above the flat part, shaped like the filter ring will help, but isn't always needed.

Does the tool start to sound cheaper?

 

[oftheherd]

...

Much depends on how badly deformed the front rim of the lens is, vs. how badly crushed the threads are.

Both must be considered.

 

[monopix]

I once straightened out a Yashica 50 f/1.7 filter ring

Strangely, that's exactly what I've got that needs straightening.

As the lens isn't really worth anything I might try knocking it out myself.

 

[Justin Smith]

Here's a pretty good write-up:

http://www.kyphoto.com/classics/filterringtool.html

Never done that repair, myself, though.

 

[oftheherd]

Here's a pretty good write-up:

http://www.kyphoto.com/classics/filterringtool.html

Never done that repair, myself, though.

Well, there you go. What's holding you back? And don't sell those Yashica lenses short. The Yashinon lenses were quite good.

 

[monopix]

Here's a pretty good write-up:

http://www.kyphoto.com/classics/filterringtool.html

That looks like the answer then. I'll give it a go and report back.

And don't sell those Yashica lenses short. The Yashinon lenses were quite good.

I agree, but they still sell for peanuts. I'm planning on adding this one to a Contax 139 I'll be selling shortly, having brought it back from the dead.

 

[charjohncarter]

I've been careful as could be, inching a filter on using finger pressure to message the ring to a deeper bit onto the ring. It never works, send it out or buy that tool.

 

[Beemermark]

If you want to use filters, and depending on how bad the the dent is, do this (I've done it a lot in the last 40 years and it works). Straighten the dent out enough that you can force a filter on. Take a crap filter of the right size and knock the glass out. Now force what's left of the filter (ring) on. Depending how bad the lens ring is you might even need to epoxy the ring on. But basically you added a new filter ring with new threads. I've done this on really bad dented lenses and, without careful examination, you can't even tell it's a repair job. The new ring looks like part of the lens. It's always good to use a little glue/epoxy (especially if the dent isn't bad) to make sure the filter ring doesn't come off with the filter.

 

[peterm1]

You can get a filter ring straightener tool but I am assuming you do not want to buy one. I have used a hole saw to cut a hole of the same diameter as this part of the lens in a piece of wood of appropriate size and around an inch or so thick. The lens has to be able to just fit into the hole. This supports the outside of the rim. Then use a dowel shaped to the same shape as the inner diameter and gently tap the lens rim back into shape by hammering on the bend part. Work from the outside in on alternate sides. With care this makes a pretty good fist of it.

 

[Murray Kelly]

I have had to do a couple of bent thread jobs in the past due to clumsiness. :bang:
The metal is usually pretty soft. Easy to distort the threads straightening the circumference.
My best bet is a solder rod, like plumbers use, as it won't damage the threads themselves as it is itself cut by the sharp threads but exerts a spread force to get the circumference of the mount back to normal. The rods are usually triangular in cross section, so use the broad flat side on the bent section of the lens, down against the ring.
Use a small - tack - hammer and go slowly. Work as if you have all day. As soon as you can mount the filter - STOP. It's not going to get any better.
I agree about Yashinon lenses. Tominor made all the Yashica lenses and were taken over by them and now make the Y-C (Zeiss) range. Never realised how good they were until too late - the Pentamatic was gone.🙁
Murray
Later - that looks an easy one with a solder stick, Monopix

 

[monopix]

Well, I used the wooden dowel and a hammer to fix it and it's very good. Filter fits Ok now without any binding or tightness. Perfect!

Thanks for your help guys.

 

[oftheherd]

...

I agree about Yashinon lenses. Tominor made all the Yashica lenses and were taken over by them and now make the Y-C (Zeiss) range. Never realised how good they were until too late - the Pentamatic was gone.🙁
Murray
Later - that looks an easy one with a solder stick, Monopix

I am often amused at the prices the Tominon lenses command on ebay, while the Yashinon sell for a pitance. Except of course for the 50mm f/1.4 or 1.2.

Good job Monopix. Now enjoy that lens!

 

[Ed S.]

I've had good luck repairing threads (2) damaged like that shown in post #6.

I use a dowel and piece of wood on standoff blocks, as others do, but I use a large C-clamp instead of a hammer, to push the dent out. Less chance of slipping, overbending, etc.

I turn the clamp handle until the dent looks repaired, then check with a filter. Repeat as necessary, until it feels correct.

 

[oftheherd]

I've had good luck repairing threads (2) damaged like that shown in post #6.

I use a dowel and piece of wood on standoff blocks, as others do, but I use a large C-clamp instead of a hammer, to push the dent out. Less chance of slipping, overbending, etc.

I turn the clamp handle until the dent looks repaired, then check with a filter. Repeat as necessary, until it feels correct.

Now that's a good idea. Thanks.

 

[FallisPhoto]

How do you fix bent filter threads on lenses?

I know you can get (expensive) tools to do it (like this one)but for the odd occasion I need to do it, I can't justify the cost.

So what do you guys use?

Actually, I bought one of those. You have to be very careful with the technique of knocking the dents out with a dowel. Aluminum is very soft and it is easy to crush the threads or bend them if the dowel is too hard. I just generally think it's best, when possible, to find a way to avoid anything that involves hammering on a camera.

 

[Pompiere]

Strangely, that's exactly what I've got that needs straightening.

As the lens isn't really worth anything I might try knocking it out myself.

I have the same lens with a dent as well. Did they come that way from the factory?

 

[janku]

If the damage is svere, the best think to do is to cover the front element, mask off the rest of the camera and then remove the bad part of the ring with fine file! Use fine needle file to dress (deburr)edges and then vacuum all the metal dust from the camera. Then if you feel like, you can touch up exposed raw metal with black paint. Once I made four notches the same size on a damaged lens and it looked like profesional job.
Cheers, Jan