Oily Zeiss C Biogon 35mm f2.8 normal?


Senior Member
Nov 10, 2008
[FONT=arial, sans-serif]Hi all, I bought a zeiss C Biogon 35mm f2.8 lens recently, and there was a lot of liquid lubricant on the lens focusing mechanism as seem from the rear of the lens (see attached picture). Does anyone have this lens? Can you check if yours has as much oil as mine does? From what I know, grease is usually used, but the store told me the following:

[/FONT]The Biogon T 35mm is a classic design lens, which mechanically lets the oil slightly flow above the mount metal pin area.
So, the oil can be seen on the mount area and that's normal. This is how it is designed.
The oil helps the helicoid move smoothly, and therefore the surface oil should not be wiped.
This slight oil won't damage the lens or the camera.

(You may gasp "this is ridiculous and cannot be". That's my reaction too. Cosina says that old Leica lenses are designed the same way, and those lenses are totally different from the recent lenses. Cosiana also says very politely that they have never received a defect report on this Biogon T 35mm lenses since they started production. ) "

Thanks in advance!