[Imaje]

Hello all,

Here's my first post, but I wanted to show my findings for anyone who has experienced the same problem.

So I'm primarily a M42 mount lense shooter. I rarely use anything other than Old screw mount lenses. This is great but it poses a few problems when it comes to adapters.

I have gone through a aftermarket adapters which either fitted snuggly, but had loose threads or had tight threads but didn't fit snuggly at all, so I resorted to buying the Official M42 adapter ring from Amazon to see if it helped.

It worked great on my Takumars which sit snuggly against the body, but it was a problem for my Zeiss lenses which although screwing all the way in, showed a little movement that is in the design of the adapter.

So, rather than modifying the lense, I looked at ways of modifying the adapter to ensure a snug fit into the body and prevent any movement of the lense.

Below are instructions on how I fixed this. Note: I accept no responsibility for any damage to your equipment as a result of performing or using this fix.

This fix will use tiny strips of tape to increase the amount of friction between the body and the adapter.

Firstly, you will need:

- Duct tape
- Official pentax M42 adapter (not shown here)
- Small, sharp scissors.
- Small flat head screwdriver

Equipment
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

We will be sticking the tape on the outside of the adapter ring behind the little 'runners' shown below
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.


So, firstly, we want to cut a piece of duct tape off and then, cut it down so it it approximately small enough to fit on the outer edge of the adapter ring.
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

Then stick this down on the outside of the ring as shown below, using the flathead screwdriver to ensure the tape is fully stuck down.
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

Do the above steps for all three of the runners found on the adapter, then, all you have to do is fir the adapter as normal, this will likely be a bit more snug than usual, but persevere and the adapter will clip in as normal. To take out the adapter, I recommend the removal tool supplied by many aftermarket adapters, or the usual pen method recommended by Pentax with a little extra umph.

And that's it, my Zeiss lense now has no movement whatsoever and so isn't a distraction when shooting.

I hope this helps. Any questions, do just ask and I will try my best to answer them.

[UncleVanya]

I haven't had a chance to look but another fix some use is to add a rubber o-ring to the setup - this and/or some flat neoprene washers to help take up the slack and make the lens fit tightly.

[stevebrot]

If I am interpreting your fix correctly, it works by defeating the "snug up to register" feature of the genuine adapter at the cost of introducing sticky duct tape* into the lens mount. If the mount flange on your CZJ lenses are too narrow to engage the K-mount flange you might want to consider one of the fixes used by other forum users. I tried to find the relevant posts, but the common fixes are to use a rubber o-ring, fabric-sheathed hair tie, or thin rubber washer on the lens side to take up the slack. With any luck, one of those users will weigh in with the details.

BTW: Welcome to the Pentax Forums!!!


Steve

* I would be particularly concerned about tape residue making its way into the interlock mechanism catch that keeps the adapter in the mount. Both it and the mount itself are designed to operate clean and dry.

[Imaje]

Thanks for the replies and thank you for the welcome. I admit this is a gutsy first post and this should be done with caution as I appreciate the possible negative side effects of using anything sticky.
Sorry Stevebrot I am not completely sure what you mean by the 'snug up to the register" feature.
I guess I was not happy that once the adapter clips in, there is still a very small amount of movement in it. Not a problem on well lubricated focus rings, but on my Zeiss it was becoming a problem. This solution still allows the adapter to clip in and behave as usual, just a little tighter than without the little tape strips.

I agree it's not without its dangers and is not for everyone Maybe a redundant post, but I couldn't find a solution that addresses the problem in this way without introducing additional bits to the lenses and therefore things to loose.

But I appreciate you both taking a look and the feedback

[stevebrot]

Sorry Stevebrot I am not completely sure what you mean by the 'snug up to the register" feature.
I guess I was not happy that once the adapter clips in, there is still a very small amount of movement in it. Not a problem on well lubricated focus rings, but on my Zeiss it was becoming a problem. This solution still allows the adapter to clip in and behave as usual, just a little tighter than without the little tape strips.

You may have have noticed that if you attach the adapter to one of your Takumars first and then attach it to the camera, it mounts like any other K-mount with the mount "tangs" tensioned by the small leaf springs on the body-side "tangs". As you unscrew the lens to unmount, the tension is released and the adapter drops slightly towards the body and becomes loose in the mount. The adapter behaves like that to ensure that the lens mount face is at the proper distance from the sensor for predictable infinity focus.

Many older German and Soviet M42 lenses have a narrow flange on the lens side that does not fully engage the mount face on the body. As a result, the adapter does not "snug up" against the tensioning springs and the lens rocks slightly in the mount despite being fully screwed onto the adapter. That is problematic both in terms of registration distance and lens axis alignment. There is also potential for light leaks. Some users on this site cope with the problem by placing slipping a hair band, o-ring, or rubber gasket over the rear of the lens to stabilize the lens and block potential light leaks.

What concerns me about your description is that you mentioned lubrication. The lens threads should mount smoothly when dry and should not require lubrication. If the threads have been damaged or are the wrong pitch*, the adapter will be difficult or impossible to attach to the lens.


Steve

* Sometimes people attempt to attach the M42 adapter to a T-mount lens (same diameter, different thread pitch) or a lens whose threads have been cross-threaded at some time. In both cases, the adapter may not fully spin on. There is also risk of damaging the adapter. Neither should be a problem for a CZJ lens in good condition.

[stevebrot]

Yep, the pentax oem adapter is designed to be pulled forward by the lens, which rests against the camera side bayonet. The wobble will occur with any lens whose base diameter is less than that of the adapter.

Thanks for the more better explanation than what I offered.


Steve

[p38arover]

Why is the thread titled "Official...."?

On reading that, I assumed this was a fix that came from Pentax.

[stevebrot]

Why is the thread titled "Official...."?

On reading that, I assumed this was a fix that came from Pentax.

I think "Official" refers to the "genuine" Pentax-brand adapter.


Steve

[awscreo]

You may have have noticed that if you attach the adapter to one of your Takumars first and then attach it to the camera, it mounts like any other K-mount with the mount "tangs" tensioned by the small leaf springs on the body-side "tangs". As you unscrew the lens to unmount, the tension is released and the adapter drops slightly towards the body and becomes loose in the mount. The adapter behaves like that to ensure that the lens mount face is at the proper distance from the sensor for predictable infinity focus.

Many older German and Soviet M42 lenses have a narrow flange on the lens side that does not fully engage the mount face on the body. As a result, the adapter does not "snug up" against the tensioning springs and the lens rocks slightly in the mount despite being fully screwed onto the adapter. That is problematic both in terms of registration distance and lens axis alignment. There is also potential for light leaks. Some users on this site cope with the problem by placing slipping a hair band, o-ring, or rubber gasket over the rear of the lens to stabilize the lens and block potential light leaks.

What concerns me about your description is that you mentioned lubrication. The lens threads should mount smoothly when dry and should not require lubrication. If the threads have been damaged or are the wrong pitch*, the adapter will be difficult or impossible to attach to the lens.


Steve

* Sometimes people attempt to attach the M42 adapter to a T-mount lens (same diameter, different thread pitch) or a lens whose threads have been cross-threaded at some time. In both cases, the adapter may not fully spin on. There is also risk of damaging the adapter. Neither should be a problem for a CZJ lens in good condition.

Another knowledge bomb, thanks! I couldn't figure out why my Vivitar 28 2.5 is super tight with the adapter, but my helios 44-2 is wobbly, and another 135 3.5 is wobbly and lets a ton of light in. Will look for solutions now that I know what to look for.

[Imaje]

You may have have noticed that if you attach the adapter to one of your Takumars first and then attach it to the camera, it mounts like any other K-mount with the mount "tangs" tensioned by the small leaf springs on the body-side "tangs". As you unscrew the lens to unmount, the tension is released and the adapter drops slightly towards the body and becomes loose in the mount. The adapter behaves like that to ensure that the lens mount face is at the proper distance from the sensor for predictable infinity focus.

Many older German and Soviet M42 lenses have a narrow flange on the lens side that does not fully engage the mount face on the body. As a result, the adapter does not "snug up" against the tensioning springs and the lens rocks slightly in the mount despite being fully screwed onto the adapter. That is problematic both in terms of registration distance and lens axis alignment. There is also potential for light leaks. Some users on this site cope with the problem by placing slipping a hair band, o-ring, or rubber gasket over the rear of the lens to stabilize the lens and block potential light leaks.

What concerns me about your description is that you mentioned lubrication. The lens threads should mount smoothly when dry and should not require lubrication. If the threads have been damaged or are the wrong pitch*, the adapter will be difficult or impossible to attach to the lens.


Steve

* Sometimes people attempt to attach the M42 adapter to a T-mount lens (same diameter, different thread pitch) or a lens whose threads have been cross-threaded at some time. In both cases, the adapter may not fully spin on. There is also risk of damaging the adapter. Neither should be a problem for a CZJ lens in good condition.

Thank you very much for the explanation, interesting and this would explain why its only my two DDR lenses with the problem of wobbling As for lubrication, I was referring to the focus ring on the Zeiss that is a little more stiff than my Takumars hence why I noticed the wobble. I read this is common in lenses of that era from the DDR and russia.

---------- Post added 12-31-16 at 02:26 AM ----------

I would happily update the title of this topic to be more accurate and or delete this thread if this is deemed an unnecessary or too dangerous a fix, but I cannot see a way to edit or delete the thread / post

[awscreo]

I'd keep it just for the sake of the explanation shared by Steve and dscshooter)

[UncleVanya]

To change the title, open the first post and edit it. Select go advanced. You should see the thread title and be able to alter it.

[Imaje]

Thank you UncleVanya, I notice that I need to be a member for at least 3 days and have posted at least 2 forums posts. So I will edit this post when I eventually see the 'Edit message' button.

[UncleVanya]

Thank you UncleVanya, I notice that I need to be a member for at least 3 days and have posted at least 2 forums posts. So I will edit this post when I eventually see the 'Edit message' button.

No worries. I hadn't remembered the restrictions.

[madad07]

I found a similar problem when mounting a Helios 44-2 onto the M42 adapter. The issue is that the body of the lens is not wide enough to touch the body of the camera - so it sits exclusively on the M42 adapter. The adapter has a bit of play, due to the small spring mechanism that keeps it in place.

My solution was to find a rubber "V Ring" washer - designed to fit onto a shaft of 43-48mm (the diameter of the rear end of the Helios is about 46mm) - then when it tightens onto the M42 adapter, the rubber is wide enough to press onto the camera body - hence creating a more secure fit and the wobble has gone!

HEre's the link to the UK company I bought my V Ring washer from (about £2.50 in 2020)
VA45 NITRILE Rubber V-Ring For Shafts 43-48mm Simply Bearings Ltd