Leitz Summicron 50/2 collapsible LTM help!

kotokot21

kotokot21

Wrenchfinder
Local time
1:45 PM
Joined
Mar 15, 2016
Messages
61
Location
Moscow, Russia
View My Gallery
Hello everybody. I've got a collapsible ltm cron that has problems with coating on the front element. I've found a service where I can recoat it but I'm can't find any info on disassembly of this lens, but they want me to take the front element away myself. After removing the decorative label ring, the front element still sits tight. Looks like it's held in by tight friction. Is here anyone who has disassembled a collapsible Summicron down to lens elements?
 
Much likely that it's very tight in its mount. Take a hair dryer, apply some heat to the front, take a soft towel underneath and tap the front (lens front down) couple times while warm. The metal mount will expand more then the glass. Had the same thing with an Elmar.
If it's not budging -> more heat and try again 😉
At some point the element should fall out.

Be careful and apply only a bit heat at a time and only to the front.

Same procedure for putting the element back in -> heat the metal up a bit, at some point the element should drop into place.
 
Filzkoeter said:
Much likely that it's very tight in it's mount. Take a hair dryer, apply some heat to the front, take a soft towel underneath and tap the front (lens front down) couple times while warm. The metal mount will expand more then the glass. Had the same thing with an Elmar.
If it's not budging -> more heat and try again 😉
At some point the element should fall out.

Be careful and apply only a bit heat at a time and only to the front.


Same procedure for putting the element back in -> heat the metal up a bit, at some point the element should drop into place.
Click to expand...

Thanks, I'll try that!
 
kotokot21 said:
... I've found a service where I can recoat it but I'm can't find any info on disassembly of this lens, but they want me to take the front element away myself. ...
Click to expand...
I wouldn't do it unless you're dealing with an expert in the field. Recoating requires the element(s) first be polished. Over-polishing will change the proper spherical properties of the glass. The fact they're asking you to disassemble the lens concerns me.
 
I think it would be best to send it to DAG or other technician who can check and calibrate the lens on an optical bench to ensure optimum performance. I think Youxin Ye can do this work.
 
kotokot21 said:
This is PS Techink https://www.pstechnik.de
Click to expand...

How bad is the coating damage? It's a great - classic lens. Personaly if its just a little coating blemish I woudn't touch it, it won't make a difference. I would just pay the repairer to take the lens out. I have repaired lenses myself but heat the metal barrel very slowly and gently will eventually help release the glass. You can also, very very carefuly use a sucktion device to lift the lens from the mount.
 
My apologies- been busy with work.

Found this diagram made from 15 years ago, last time I took apart a Summicron.
The collapsible has the same layout.



The front element is in tight. I use some soft rubber suction cups, with a little bit of lens cleaning fluid on the glass, to get the elements out.
The Rigid lens- even tighter than the collapsible.
 
The earlier collapsible Summicron (from number 11XXXXX) has a very soft front glass, I've never seen a perfect example.

The later collapsible Summicron (number 13XXXXX) has a tougher coating and is usually in a better condition.


gelatine silver print (summicron collapsible 50mm f2) leica III

Erik.

48009600078_28942f4a7a_b.jpg
 
The collapsible Summicron with SN lower than 1050000- use Thorium Glass for the front element. I had mine polished and recoated some years ago, by Focalpoint. He is now retired.
 
You must log in or register to reply here.
Back
Top Bottom