I just received the beautiful Bessaflex TM which is known as the last built SLR film camera taking 42mm SLR lenses. Since I'm using Carl Zeiss Jena lenses for my ARAX 60 medium format camera and because of the very good reviews about the Carl Zeiss Jena MC Flektogon 2.4/35, I bought this lens for the Bessaflex. When it arrived I discovered that the mirror hits slightly the back of the lens when focused at infinity. I had to adjust the focus to 3m that the mirror snapped back in the down position. But this problem can be solved very easily within 10 minutes and with very basic tools and skills.
What tools are required?
Well, basically only a file and a lens spanner is required to rasp the back of the lens a little bit down.
To do so, the back of the lens needs to be unscrewed with a lens spanner. (outer spanner marks at the back of the lens) After put the back lens assembly on a table and start filing. Be careful not to scratch the lower and upper glass. I highly recommend some sort of compressed air or rocket blower to blow the fine aluminum chips out of the lens before assembling the back again on the lens to try if the removed material was sufficient.
All in all it's a very easy mod. Only be careful with the fine chips after rasping. Use compressed air to clean the back part very well before assembling it at the lens again. Also be careful while rasping and avoid scratching the glass. Don't use a tissue to remove the chips from the glass!
After the modification, the lens works perfectly on the Bessaflex TM!