mold-fungus removal on old LF lens

[Stefan F.]

Hello,

I have a Steinheil Muenchen Triplar-Anastigmat f3,8/36cm LF-lens that has mold and/or fungus on the rear side of the removed front lens - see photos. How can this be removed and cleaned properly?

Thanks, Stefan

[Steven Tribe]

Welcome back - you may get moved to the DIY thread!

Remove the retaining inner screw ring (normal anti-clockwise!).
Take out the achromat lens.
Hold the lens over soft surface ( it can be dropped) by the edges. Blow loose material away from both surfaces ( there will be metal and sand particles present.
Buy a spray can of Lens Cleaner at your nearest optician.
Spray one surface at a time until it pools.
Leave for a couple of hours.
Move a professional quality tissue around slowly to disturb and move the debris. Do not rub! - just like a lover’s caress.
Wipe the lens carefully.
Repeat with new spraying. More friction can be applied as most debris is removed.

Spores of fungi are everywhere, so there is no way to prevent attack. In modern homes there is little chance of new growth.

[Greg]

Google how to clean a telescope's mirror lens. Probably 20 plus years ago I had a vintage Criterion 8" reflector telescope that the mirror looked to be totally "unreflective" because of the dirt, fungus, dust, and more on it. If I remember correctly, I let it soak in distilled water with a very, very dilute, warm at first, solution of Ivory detergent for a few days. Then rinsed it in distilled water many times. Then very ever so gently and slowly dragged sheets of Kodak Lens Cleaning tissue (two packs worth) over the surface. In the end the mirror was literally "as new".

[nolindan]

What wrecks a lens is rubbing. To that end, I use Windex as an aggressive cleaner that doesn't leave residue. You may have to repeat the cleaning process over and over. If the fungus has been aggressive it may have etched the AR coating and glass - so it is possible you can't clean it back to a pristine condition - check for etching with a 10x or better loupe.

[jtomasella]

There is a camera restore place that uses CLR rust remover.

[Stefan F.]

Thank you all!

Best regards, Stefan

[nolindan]

Oh, and be sure to clean out the inside of the lens and other elements. If it were my lens I would take everything apart and clean all the parts in bleach to get rid of spores. You mentioned in an earlier post that the diaphragm was stuck so you will likely have to take the lens apart in any case.

[maltfalc]

Oh, and be sure to clean out the inside of the lens and other elements. If it were my lens I would take everything apart and clean all the parts in bleach to get rid of spores. You mentioned in an earlier post that the diaphragm was stuck so you will likely have to take the lens apart in any case.

you can't get rid of spores, they're everywhere, and you shouldn't be using corrosive chemicals like bleach on a lens. the only thing you ever need to do to prevent fungus is avoid high humidity. anything else is a waste of time, at best.

[nolindan]

Came across this while, natch, looking for something else: https://richardhaw.com/2016/03/27/re...ngus-cleaning/

[Jim Noel]

PLain old Listerine works wonders and doesn't attack the glass. No rubbing.