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Lens Fungus
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PostPosted: Sun Jun 18, 2017 11:48 am    Post subject: Lens Fungus Reply with quote

Article from a 2011 edition of Amateur Photographer magazine.





PostPosted: Sun Jun 18, 2017 12:15 pm    Post subject: Reply with quote

Like 1 small Like 1 small Like 1 small Thanks for sharing!


PostPosted: Sun Jun 18, 2017 4:19 pm    Post subject: Reply with quote

Thanks Edgar!

"... old, unit focus prime lenses" -- what is "unit focus"?!

The pronouncement that "if the fungus has etched the glass, the lens is useless" depends, as we all know...

Just because the author may have destroyed most of the lenses he tried to fix doesn't mean that will be everybody's experience. There are plenty of examples here at MFlenses.

And that "shelf above a radiator or heater" should be positioned to limit high temperature...


PostPosted: Sun Jun 18, 2017 6:04 pm    Post subject: Reply with quote

I've had 100% success (so far) in removing fungus by putting a dab of Clotrimazole, commonly found as an anti-fungal cream, to each side of the glass element and gently rubbing between thumb and forefinger for a minute or so. To date, all it has removed is the fungus, with no degradation of anything else. I've been doing this for a few years now, but not come across anyone else on the internet doing the same, so I'm my own tester on this one.

I've not rinsed the cream off my pk lenses, but just polished it off, as I want to see if that leaves any 'active' protection, having looked into how Clotrimazole works. But on my m42's I've rinsed, then polished.

And in case it's not actually the Clotrimazole that is doing the business, here's what else is in my old tube of 'dual action treatment for athletes foot' -

Benzyl alcohol
Polysorbate 60
Sorbitan stearate
Cetyl palmitate
Cetostearil alcohol
Octyldodecanol


PostPosted: Mon Jun 19, 2017 2:57 am    Post subject: Reply with quote

On every lens I've disassembled to clean up fungus, I've simply shot the glass with Zeiss lens cleaner and wiped it off.

I'm a bit of a brute with these things though.


PostPosted: Mon Jun 19, 2017 8:02 am    Post subject: Reply with quote

Sciolist wrote:
I've had 100% success (so far) in removing fungus by putting a dab of Clotrimazole, commonly found as an anti-fungal cream, to each side of the glass element and gently rubbing between thumb and forefinger for a minute or so. To date, all it has removed is the fungus, with no degradation of anything else. I've been doing this for a few years now, but not come across anyone else on the internet doing the same, so I'm my own tester on this one.

I've not rinsed the cream off my pk lenses, but just polished it off, as I want to see if that leaves any 'active' protection, having looked into how Clotrimazole works. But on my m42's I've rinsed, then polished.

As you're rimazoling those clots by "gently rubbing between thumb and forefinger," don't you end up with any tiny scratch marks on the coating? Smile


PostPosted: Mon Jun 19, 2017 9:46 am    Post subject: Reply with quote

konicamera wrote:
Sciolist wrote:
I've had 100% success (so far) in removing fungus by putting a dab of Clotrimazole, commonly found as an anti-fungal cream, to each side of the glass element and gently rubbing between thumb and forefinger for a minute or so. To date, all it has removed is the fungus, with no degradation of anything else. I've been doing this for a few years now, but not come across anyone else on the internet doing the same, so I'm my own tester on this one.

I've not rinsed the cream off my pk lenses, but just polished it off, as I want to see if that leaves any 'active' protection, having looked into how Clotrimazole works. But on my m42's I've rinsed, then polished.

As you're rimazoling those clots by "gently rubbing between thumb and forefinger," don't you end up with any tiny scratch marks on the coating? Smile


The cream I use doesn't scratch. Or at least it doesn't appear to scratch under a a 10x loupe which I use during the process. But you've made me ask myself another question - if I've ever had to clean fungus off a coating using this method. I'll have to have a think, as I can't categorically say yes.


PostPosted: Mon Jun 19, 2017 11:06 am    Post subject: Reply with quote

visualopsins wrote:

"... old, unit focus prime lenses" -- what is "unit focus"?!
...


Unit focus: All the lenses are moved together to focus the lens.
In contrast internal focus, or Nikon CRC or floating elements move only some lenses but not all to focus.
There are sometimes one or more groups of lenses moved on cams. This allows for better correction, and easier focus -- often needed for big tele lenses, or autofocus.


PostPosted: Mon Jun 19, 2017 2:45 pm    Post subject: Reply with quote

ZoneV wrote:
visualopsins wrote:

"... old, unit focus prime lenses" -- what is "unit focus"?!
...


Unit focus: All the lenses are moved together to focus the lens.
In contrast internal focus, or Nikon CRC or floating elements move only some lenses but not all to focus.
There are sometimes one or more groups of lenses moved on cams. This allows for better correction, and easier focus -- often needed for big tele lenses, or autofocus.


Thank you!