Mod CZ Biogon 35mm for Leica RF with Amedeo Adapter

[simonOWO]

Old Contax biogon lens won’t work on Leica because the big rear element will interfere with the rangefinder coupling.

I was able to modify a CZ biogon to work on leica rangefinder with Amedeo adapter, and would like to share here. It wasn’t a perfect mod because I made some mistakes in the process.

Original biogon with rear part (mainly the rangefinder coupling mechanism for Contax) too large


I discovered that the lens would fit without the original rangefinder coupling mechanism. The space left is tiny, so I don’t know if this method would work for 21mm biogon.




So I decided to cut the rangefinder coupling mechanism in half and remove the excess, I removed a bit too much in this step, so I have to cut the spring also, otherwise the spring won’t fit. And glue back together again.





Now it fits with rangefinder coupling.

 

[santino]

You are a brave man and it paid off!

 

[simonOWO]

Thank you, it was a stressful week for me, this was a good break from the work.

Do anyone know how to disassemble and access the focusing helicoid? it wasn't immediately obvious to me.
I am interested to service the helicoid with new lubricant, it's kinda sticky and stiff.