innovative and drastic way of remove fungus

Jesito · Expire: 2015-01-07

Fungus are one of our daemons. Once infected, the lenses (even carfully cleaned) can develop again more fungus due to the remaining spores.

That's what I told my friend Angels, that is a beginner with the MF lenses and her Olympus E-P1 (This is her picture repository)

Martinsmith was so kind of sending me a nice FD 50mm 1.8, (a little fungused) for her. I dismounted the front element, where most of the fungus was visible and cleaned it. Next, I put the lens under the UV bath for a couple of days. And gave it to Angels (thanks, Martin!).

She didn't tell me, but remembered what I told her about the fungus. She was a little scared about the lens ans its infectious capabilities. She's working at a big hospital and they have several autoclaves to sterilyze many things made up of steel, glass and fabric. She knows the autoclave kills fungus, and being the lens made of glass, metal and strong plastic, should'nt pose any problem. But she didn't tell me before. I would have suggested to take apart the lens and put it into the autoclave in parts...

So the lens went into the autoclave and passed a cycle to kill fungus.

Some days later we met to talk about photography and share a coffea, and he brougth me the lens, and explained the process.
At first I thought the barrel could have lost the engravings, but after a close inspection I didn't see any damages outside. But inside the lens, several big spots on the top lenses show the process wasn't innocuous at all. And also, the diaphragm blades didn't move at all... That means I have to open it and try to fix it.

In spite of the current result, the idea seems very good to me. A way of assure the fungus are killed even if they are inside small and unaccessible places. So we'll have to repeat the test in different conditions, not with the whole lens assembled.

She took some pictures to document it:

And this is the lens after the treatment:

Now is time for a disassemble. A

Regards.
Jes.

LucisPictor · Expire: 2013-12-03

Hmmm... I don't know what to think about it.
You remove the fungus and pay for it by having stains on the front element and non-working blades?

BTW, I have started to experiment with ozone. Also some kind of dangerous stuff, can harm your lungs.

Jesito · Expire: 2015-01-07

Sevo · Expire: 2012-12-03

All water should vanish in the initial vacuum treatment of an autoclave - but as the lens would later be flooded with 121°C hot steam, there would be more water inside after than before the process...

exaklaus · Expire: 2011-12-02

In former days, when a fungus infected lens came back to Zeiss Jena service, they threw away the complete glasses and the metall barrel was put into a chamber with fungizid poison to kill the fungus.

Klaus

Sevo · Expire: 2012-12-03

ForenSeil · Joined: 15 Apr 2011 Posts: 2726 Location: Kiel, Germany.

Cool method!
Instead of an autoclave 20-30mins in an pressure cooker will also work well to kill the fungus and spores.

LucisPictor · Expire: 2013-12-03

Originally, I use ozone in order to destroy smells from used bags and so on. That stuff works wonder there.

But after I have put a lens inside a closed plastic bag in which the ozone is procuded by a small generator and left it in there, I can't judge if it has helped or not. The lens did not have any fungus, just some "thing" inside which could have been anything.
The ozone treatment was just some extra measure.

I would not be able to say that ozone helps against fungus infection and would rather think it doesn't.