Repairs to M42 Super -Takumar 150/f1.4 lens lens

Bellakelpie · 12-05-2008, 04:59 PM

The front cover ( where filters and the hood screws onto) of my M42 Super -Takumar 150/f4 lens is loose and rattles around. its the metal piece just forward of the knurled manual focus ring.

The rest of the lens, including the front element, is fine and tight and the performance is not affected.

Any ideas or hints as to how I can tighten the front part up?

I was considering putting a couple of drops of cyano glue under the said cover, but will not do anything until I have heard from others who may have more knowledge than I.

stevebrot · 12-05-2008, 05:10 PM

Usually those parts tighten with a spanning wrench that engages slots on either side of the front of the lens. Without seeing your particular lens, I can't say for sure.

In any case, LEAVE THE GLUE IN THE CUPBOARD!!!!

It is better to do a real repair than to permanently make a lens unrepairable. (Usually the first step to disassemble is to remove the front face from the lens.)

Steve

Indianadinos · 12-05-2008, 05:17 PM

Hello,

The front part of your lens should be retained by three screws, which you can access by removing the front name ring ...
Browse to my blog at Shooting with a Pentax K10D, then click on the "Repair" link in the Categories menu on the right ...
The first three posts that show up are about fixing a Flektogon, the fourth one shows how to fix the infinity focus on a Takumar 24. Look at the pics from this post, the front name ring and the screws of the retaining ring of the 150/4 should be accessed the same way than on my Tak 24/3.5 (i did the same intervention on my 50/1.4 too) ...

Hope this helps.

Best regards

*Ratmagiclady* · 12-05-2008, 05:22 PM

And to reiterate: No glue! No superglue or any other cyanoacrylic type glues anywhere near anything optical... Just the vapors from that stuff can fog your glass and plastic unrecoverably.

Danger, Will Robinson!

Mike Cash · 12-05-2008, 09:50 PM

Originally Posted by Bellakelpie

.......a couple of drops of cyano glue.....

That stuff fumes up and gets all over everything. Generally not a problem in normal use, but you don't want the fumes settling on your nice optical glass and ruining it.

As testimony to the fumes power to get around and settle in an extremely fine mist all over everything, consider the fact that it is commonly used in forensics for bringing out fingerprints.

Interesting Video with Annoying Music

richard64 · 12-06-2008, 04:55 AM

Hi Indianadinos

Originally Posted by Indianadinos

The first three posts that show up are about fixing a Flektogon, the fourth one shows how to fix the infinity focus on a Takumar 24. Look at the pics from this post, the front name ring and the screws of the retaining ring of the 150/4 should be accessed the same way than on my Tak 24/3.5 (i did the same intervention on my 50/1.4 too) ...

Just a question about your infinity adjustment on the 24/3.5. Why did you remove the filter ring? Can you adjust infinity just by loosening the screws on the barrel?

Richard

Bellakelpie · 12-06-2008, 01:42 PM

Thanks guys. CA is still in the fridge!.
It is the name ring /filter ring that is loose. How do I tighten that?
Had a look at your blog Indianados, thank you. But I am still a little confused.

Indianadinos · 12-06-2008, 05:23 PM

Hello Richard,

Originally Posted by richard64

Hi Indianadinos

Just a question about your infinity adjustment on the 24/3.5. Why did you remove the filter ring? Can you adjust infinity just by loosening the screws on the barrel?

Richard

Frankly, i don't know ... Removing the filter ring was needed to access the three screws that bind the focusing barrel and the helicoid, so that the focusing barrel became loose ... I must confess that i don't know if the three screws on the barrel of the lens will have the same effect (in fact, i confess i didn't notice them before you talked about) ...

Best regards

Indianadinos · 12-06-2008, 05:31 PM

Hello Bellakelpie,

Originally Posted by Bellakelpie

Thanks guys. CA is still in the fridge!.
It is the name ring /filter ring that is loose. How do I tighten that?
Had a look at your blog Indianados, thank you. But I am still a little confused.

Just get a kitchen sink cap (possibly, one made of soft plastic, to avoid scratching the front lens), then put it on the front side of the lens, so that it will adhere to the name ring, and then just turn the basin cap, to screw in the name ring ...
The hard part of the story, is to find a basin cap of the right size, i was lucky enough to find a multi-sized cap made of very soft plastic ...

Eventually, you could even use a small plastic pipe, provided that you find one of the right diameter ...

If still in doubt, i will post here some pics of the basin cap in action ...

Hope this helps

Best regards

P.S.: The name ring is just the front ring of the lens with the lens name, while the filter ring is where you have to screw in the name ring, and it is a different part of the lens ... If the filter ring is loose, too, you have to fix this at first ... Try to GENTLY move the filter ring: if it moves, it needs to be fixed, so post a reply here and i will post the pictures of the whole sequence ...

jamonation · 12-06-2008, 05:32 PM

Rubber stoppers ftw! I've not tried but been meaning to tighten the front ring on my 50mm f1.4 Takumar. I've read in a few places that rubber stoppers like these are great for grabbing on and creating just enough friction to cinch the ring into place:

Rubber Stoppers: Solid: Each: Choice of 20 Sizes

Bellakelpie · 12-06-2008, 08:00 PM

O.K. I have had a closer inspect and its starting to become clearer in my muddy mind.
It would appear that the 3 screws that Indianos mentions are the problem. They probably are loose, or have even fallen out.
So , I will take a trip to my local hardware store, with the lens in hand, for a plug fitting. (That's going to raise some eyebrows me thinks. A guy trying to repair photographic equipment by going to a plumbing supply shop!!!??)

Zewrak · 12-07-2008, 12:59 AM

Originally Posted by Bellakelpie

O.K. I have had a closer inspect and its starting to become clearer in my muddy mind.
It would appear that the 3 screws that Indianos mentions are the problem. They probably are loose, or have even fallen out.
So , I will take a trip to my local hardware store, with the lens in hand, for a plug fitting. (That's going to raise some eyebrows me thinks. A guy trying to repair photographic equipment by going to a plumbing supply shop!!!??)

Ive used hammers and screwdrivers.

Anyways. I have been successful using a small screwdriver and put it into one of the etched letters and GENTLY push the ring around. Rubbergloves and using the thumbs might also work. I also remember using a backcap of a lens in a glove to get friction to work.

And it is most likely the screws. They were glued from factory with something that looks like green plastic, also used on electronics to keep parts where they are supposed to be. Someone has probably taken the lens apart once and not reapplied whatever glue they were using. I have the same problem with my 50/1.4 which I have to tighten pretty much every second month.

*rayallen* · 12-07-2008, 01:28 AM

You will find all the instructions you need here:

Pentax 50mm f/1.4 strip-down instructions

richard64 · 12-07-2008, 11:00 AM

Originally Posted by Bellakelpie

O.K. I have had a closer inspect and its starting to become clearer in my muddy mind.
It would appear that the 3 screws that Indianos mentions are the problem. They probably are loose, or have even fallen out.
So , I will take a trip to my local hardware store, with the lens in hand, for a plug fitting. (That's going to raise some eyebrows me thinks. A guy trying to repair photographic equipment by going to a plumbing supply shop!!!??)

FWIW, if you cannot get the right plug, here's an alternative.

When I removed the name plate of my Super Tak 28/3.5 (58mm filter ring) I used a 49mm push-on lens cap. This cap came on a CZJ 135/3.5, but I've also had one on a SMC Tak, so I guess they are generic. I wrapped the lens cap in a latex glove to give friction and then pushed it on the same way round that I would put it on a 49mm lens, so that the rim of the cap touched the name plate. I guess the Tak had not been opened in 40 years and the name plate was a real bugger to move. I even stopped after a while dispairing that it would not move, then I tried again the following day with a bit more force and the name plate moved.

An M42 end cap is just the right size for a lens with a 49mm filter.

Richard

Bellakelpie · 12-07-2008, 01:08 PM

Thanks heaps for all the useful hints, fellow "Pentaxians."
Looks like I have something to do during the Christmas/New Year break, which should not annoy the wife!
I will get back with the results.
Cheers
Dave