Cleaning from fungus: Zeiss Biometar 80 f/2.8 ...

Having a spare P6-to-Pentax-K adapter, i decided to give a try to this lens, but, when ready to go shooting, i noticed the evil traces on the front element (the picture on Flickr has a note showing where the filaments are):



So, time for the rescue team to act again ...
To access the front element, at first the name ring must be removed. The classic sink cap helps a lot ...






Name ring removed, now time for the front element retaining ring.




Note that there are more rings inside the lens, only the inner one needs to be removed ...




The retaining ring of the front element is unscrewed.




Be careful: the front lens is loose now, although it may be necessary to reverse the lens and shake it a bit to let it drop in your hand.




Now, the cold cream comes to play. I used Avene's one simply because it is widely available in France: you can use the Pond's one, or whatever you find in the beauty case of your wife/sister/mother (better to ask first, in such a case) ...




Using the fingers, the cream is spread across the whole lens, and set to dry for about an hour ...




After about an hour, use some q-tips with a few drops of Zippo fluid to remove the cream ...




... and repeat the last two steps on the outer side of the lens, to remove the eventual cleaning marks ...






Last, use some optical fluid on a micro-fiber cloth to clean again the lens.




Now, store somewhere the front element, and start the cleaning process on the inner element. It easily unscrews from the lens body using the now classic cap ...






The inner element may be easily remooved from the support by simply unscrewing the rear part. Here are the two lenses of the second element glued together ...




... and after the cold cream application ...




After an hour, repeat the cleaning steps with the Zippo fluid first and the optical liquid after, and reassemble the lens. As you can see, the evil fungus is no longer here ...




Now, the Biometar is ready for its next mission ;-) ...