Leitz 40mm f/2 Repair and Focus Tap

[Erik Gunst Lund]

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My Trusty little Leitz 40mm f/2 was suffering from aging grease, Canada Balsam and the internal black paint had begun to become detached also so a repair was needed I also wanted to add a modern focus tap.

Since the lens is so cheap I decided to try it out myself.

I have a lot of knowledge about AF and MF Nikkor, Cannon Olympus and Vooigtlanders SLR and Leica mount lenses, most parts of the design and build is same same :-) but this tiny Leica has some differences as to how it's put together, first I was very disappointed to find that the front threads part series 5.5 threads is glued to the aperture housing, next I found that the rings that 'normally' have two holes or ridges for lens spanners for tightening the old Leitz lens had one or even none, so had to be taken apart with friction, a rubber tube of the right thickness must be used to reach into some parts of the lens to get it apart, I modified these rings, drilling two holes makes the hole deal a lot easier.

Got it all dismantled and sorted out, the two elements with the Canada Balsam issue got a 'cooking' treatment in boiling water to separate the two halves.

A drop of Araldite Krystal and the two are inseparable, a coat of mat black paint to finish the job off.

Putting everything back together without leaving dust or prints is the worst part...

The old gease was cleaned off and the many threaded focus threads lubed with new grease and put back together as marked by disassembly.

The new focus tap needed a slight trim to clear the mounting ring and two extra location holes to keep it in alignment a single screw holds it in place.

Everything fits within very tight tolerances; position of glass elements, focus threads so it was a joy to work on it.

 

All the parts, note extra holes, the two glass element front center

 

Extra holes for focus tap in focus mount.

 

Focusmount with focus tap.

 

24 hours wait for the Epoxy to cure and testing today went very well, focus at infinity and all the way to 0.7m is spot on.

Lens is now in good service condition and much closer to my heart

[Michael Geschlecht]

Hello Erik,

 

Cogratulations. Well done.

 

Are you able to test to see if there is a different color cast from using the Araldite Krystal in place of the Canada Balsam?

 

Did removing the Canada Balsam effect any of the lens coartings on the surfaces or blackening on the edges?

 

Best Regards,

 

Michael

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[Erik Gunst Lund]

Canada Balsam has a very very faint brown tone, the Araldite Krystal is completely clear...

No obvius difference.

The balsam dissolveres easily in hot water and just slides off so no damage at all to coatings.

I removed the excess glue with a scalpel. So yes it is very important to apply new mat black paint to avoid reflections and flare.

[lct]

Pity i don't have your skills as i'd love to get a focus tab like this. Just a question. Can you move the tab the way below (with the index finger) in spite of the small size of the lens?

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[Erik Gunst Lund]

Thanks!

 

No, not with large hands like mine...

 

I use the fingertip to move it.

[Joska]

On 10/5/2012 at 9:42 PM, Erik Gunst Lund said:

My Trusty little Leitz 40mm f/2 was suffering from aging grease, Canada Balsam and the internal black paint had begun to become detached also so a repair was needed I also wanted to add a modern focus tap.

Since the lens is so cheap I decided to try it out myself.

I have a lot of knowledge about AF and MF Nikkor, Cannon Olympus and Vooigtlanders SLR and Leica mount lenses, most parts of the design and build is same same 🙂 but this tiny Leica has some differences as to how it's put together, first I was very disappointed to find that the front threads part series 5.5 threads is glued to the aperture housing, next I found that the rings that 'normally' have two holes or ridges for lens spanners for tightening the old Leitz lens had one or even none, so had to be taken apart with friction, a rubber tube of the right thickness must be used to reach into some parts of the lens to get it apart, I modified these rings, drilling two holes makes the hole deal a lot easier.

Got it all dismantled and sorted out, the two elements with the Canada Balsam issue got a 'cooking' treatment in boiling water to separate the two halves.

A drop of Araldite Krystal and the two are inseparable, a coat of mat black paint to finish the job off.

Putting everything back together without leaving dust or prints is the worst part...

The old gease was cleaned off and the many threaded focus threads lubed with new grease and put back together as marked by disassembly.

The new focus tap needed a slight trim to clear the mounting ring and two extra location holes to keep it in alignment a single screw holds it in place.

Everything fits within very tight tolerances; position of glass elements, focus threads so it was a joy to work on it.

 

http://farm9.staticflickr.com/8040/8057350491_49f24340ba_b.jpg

All the parts, note extra holes, the two glass element front center

 

http://farm9.staticflickr.com/8038/8057350337_82e5199964_b.jpgExtra holes for focus tap in focus mount.

 

http://farm9.staticflickr.com/8309/8057350368_18a6ab2d0c_b.jpgFocusmount with focus tap.

 

24 hours wait for the Epoxy to cure and testing today went very well, focus at infinity and all the way to 0.7m is spot on.

Lens is now in good service condition and much closer to my heart

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Awesome, I love my cron c but it focuses right only at f16/11 so I have to guess at lover apertures or just use zone focus. Great reportagedude👏🏽✌️✌️

[Greenhilltony]

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I have a Minolta M-Rokkor QF version, as it wobbles a bit I want to tighten it by myself. However I couldn't make the seemingly retaining ring on the back to spin, so I wonder how to fix it by myself without dissembling everything of the lens.