M-Elmar 50mm/2.8 dissasemble

[SergioGuerra]

Hi there!

I need to access the front element in order to clean it, but don't seem to find directions on the web in order to the proper order to disassemble the lens. I really only need to access the front element, can I do it from the front? How do I remove the collar around the element?
Any help would be really very appreciated 🙂

Regards,

Sergio

 

[Cronilux-M]

It may just be threaded- I had a new 75/2 that was loose up front- I simply tightened it face down on a sheet of rubber. It worked fine- and was a lot faster than several months in NJ.

 

[nobbylon]

If you want my advice, don't do it! I've had a few and tried to access the front element on a '65 version. The central black piece screws out by using a rubber dolly or a large enough pencil eraser. (carefull of the front element as the coatings are soft). This then allows the ring with all the writing to come out. You now need the special lens calipers to undo the ring holding the front element, however once removed you will if I remember correctly, still not be able to remove the element as although it moves, it is held by a very thin shim. The only way I could see to let the element drop out was to lever this shim out however it's so thin it will break. I didn't bother and stopped there! Unless you have spare shims I wouldn't. Send it in.
regards j

 

[SergioGuerra]

Oh well, I managed to remove the shim without breaking it, but the front element still didnt came out. It looks like it doesnt come out from the front, and I really dont know how to access from the back. Any ideas?

The kind of haze I have is only around the outside of the front lens, and is very very hazzy. From what I have read on the web, It should be rests from the aperture blades oil.
I know the internal coatings are very thin and will come out if I try to clean it, but paying $250 to repair a $150 lens seems a bit silly to someone on a tight budget like me. Besides, I am a wide angle guy and would really think seriously on doing this if It were a 35mm... (It came with my "new" M2... I really cant live without one!)

Looks like I have two alternatives:

- Use this lens like it is and stop it down to 5.6 (at 5.6 aperture blades block the hazy part of the front element) or use it wide open for strange effect and "old look" portraits;

- Sell it like it is, but I am not sure of how much would it sell, in this condition... (anyone knows/is interested?)

What would you do?

Regards and thanks for the tips...

Sergio

 

[SergioGuerra]

Ok, I managed to remove the front element, and tried to clean it. The problem is that the glass/coatings is really affected by the aperture blades oil, and it will only disappear if I could re-polish the element or obviously replace it.
Both these options are economically in viable atm for me..

So I was finishing a HP5+ roll and decided to do a small very non scientific test to see how usable can this lens be.
Rainy day here in Portugal, so it had to be inside my house but decided to do it agaisnt the outside light just to see better the probable flare from the damaged elmar.
Tested it agaisnt a Industar-61 know for sharpness and contrast... (equipped with a sun shade).
I know this test doesnt mean much, since a simple difference in apertures from one lens to other makes different results, but just let me know what do you think... I believe the elmar is very usable below 5.6 and usable a 4... 2.8 is somewhat "flary"...




Regards,

Sergio