stuck m42 adapter


Link Posted 05/06/2020 - 01:07
Ok , I have already looked at utube videos for an answer to this , and I have already attempted some strategic poking the lens with a pen and of course brut force but to no avail.
I have a genuine m42 to K mount adapter, which I attached to a M42 55mm f2 lens.
I have not attached the lens with adapter to the camera yet, but when I when I attempted to remove the adapter, it would only move marginally, but I cannot unscrew the adapter from the lens .
As usual , I am turning to forum members in search of a solution.
Thank you in advance.



Link Posted 05/06/2020 - 01:43
Wrap the lens in a towel and secure it in a vise NOT hard - it shouldn't be necessary. Place a narrow bit of wood or something else with a flat end against one of the flange protrusions and hit the other end of the wood/ implement smartly with a hammer. If you don't have a vise then jam it in a drawer or shove it up against something just sufficiently to prevent the lens from revolving when you hit the adapter. I also discovered that putting the adapter on the lens was a bad idea! When it's on the camera, the little spring prevents it from moving so you have to unscrew the lens off the adapter anyway. I don't know who thought up putting the adapter on the lens first - he needs talking to. It's easy to remove from the camera. You simply shove your thumbnail in the slot to depress the spring. (If you don't have a thumbnail, then grow one. You will need it if you are going to be using M42s!).
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Last Edited by davidwozhere on 05/06/2020 - 01:47


Link Posted 05/06/2020 - 03:30
Cheers., I should have read the instructions first and attached the adapter to my camera.I have attempted to attach the lens to one of my cameras, but strangely it won't attach.I have attempted the towel method , but may leave it till tomorrow , after some Weetabix , for energy.


Link Posted 05/06/2020 - 06:16
theonenadeem wrote:
Cheers., I should have read the instructions first and attached the adapter to my camera.I have attempted to attach the lens to one of my cameras, but strangely it won't attach.I have attempted the towel method , but may leave it till tomorrow , after some Weetabix , for energy.

That is strange. Perhaps the adapter has distorted ? Or the spring strip has been bent out of position. I would suggest removing it with a mole grip or the like and throwing it away.

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Last Edited by pschlute on 05/06/2020 - 06:20


Link Posted 05/06/2020 - 06:52
There’s a little ‘spring’ that holds the adapter in place that has to be depressed before removing the adapter.
Some of them can be snug as well so takes a bit of effort to turn after depressing that spring.


Link Posted 05/06/2020 - 07:57
Thanks to everyone who responded , Somehow managed to unscrew the lens from the adapter .

But the adapter seems too large , for the camera mount.

This is supposed to be an authentic adapter , anyone have any suggestions ?


Link Posted 05/06/2020 - 07:59
Do you have pictures of either the camera or the mount, or alongside each other etc? Usually that helps us help you


Link Posted 05/06/2020 - 08:30
I'd agree with others that the adapter is perhaps a little warped. I've never seen that with a genuine Pentax one but maybe it's a fake, though I don't believe there are many fakes out there, just cheaper designs made with cheaper materials.

I think the manual states that the adapter should go on the lens first, then onto the camera but I always put it on the camera and screw the lens in and have never had a problem with it. The only problem I ever had with an M42 adapter was a third party one that got stuck while trying it out in a used camera shop. Luckily they also do repairs and quickly removed it for me, but the experience put me off M43 lenses on my DSLR for years.
Pentax hybrid user - Digital K3 & K200D, film 645 and 35mm SLR and Pentax (&other) lenses adapted to Fuji X digital
Fan of DA limited and old manual lenses


Link Posted 05/06/2020 - 17:14
I have not seen the 55mm f2.0 lens, but does it have anything on the face of the rear flange that might be fouling one of the slots on each side of the adapter? An extra little pin, or a slightly proud screw head?

Years ago I had a 28mm SMC Takumar which had a tiny pin, of obscure purpose, that projected from the face of the flange close to the M42 screw. It gave no trouble in a genuine Pentax M42-PK adapter, nor on the very good quality one marketed by Jessop, but it fouled the slots on a Kood adapter. Once the Kood was screwed on, it could only be removed if one could depress the little pin - which of course was impossible if the assembly had been clicked into place on a PK camera!

If some tiny projection from the seating flange of the lens is fouling in the slots of the adapter, then I would think that it cannot be a genuine Pentax product.

I wrote a review of some adapters back on 7 August 2012 under "M42-PK adapters".

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Link Posted 05/06/2020 - 17:44
Martin , I have removed the lens from the adapter.
I have looked at a photo of an original adapter on WEX website and mine looks identical. With the adapter attached the pin on my lens is visible.
Now that the adapter is removed I attempted to install the adapter on my K7, but it did not want to attach. After the dilemma with the lens , I am reluctant to attach the adapter to , one of my modern Pentax bodies.
I will search for your review


Link Posted 05/06/2020 - 17:46
When you put the legit adapter onto the camera mount you may have to push down the little springy bit in order to get it on. It then slides fairly freely into position.

Also, if you want to remove an M42 adapter from a lens then simply put a PK cap over it and twist. You'll get so much more leverage this way.
All the gear with no idea


Link Posted 05/06/2020 - 19:01
Joy....Success. Unsure how I inserted the adapter , but I do not really care , just now , It works, happy days and thanks you to everyone who posted.
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