Fungal Growth

Hi all
It may be a bit of a 'stupid' question but I honestly do not know the answer.
If a lens has small fungal growth, is it possible from spreading and how would I do this?
Also can fungal growth spread to other lenses (contaminating)?
I ask as a friend has two lenses I am interested in for a good price but one of the lenses has some small fungal growth (an I really mean small).
I just was wondering if there is anything I could do and if I would contaminate any other lenses that may be stored close by?
I would appreciate any help on this one.

i'm sure someone here will be able to help

but AFAIK it can spread to other lenses,but can be cleaned or i believe "microwaved

The air is full of fungus spores, all it needs is the dark, damp conditions plus some optical glass or balsam and away it goes. Keep contaminated lenses away and store little used lenses in a dry, well ventilated condition.

Existing fungal growth can be cleaned, but it may need a lens recementing if between elements and may well not be worth it. If it's gone so far as to etch the glass, then it's too late.

Wasn't something mentioned about Ultraviolet light in the past John ?

Try some sunlight on a window ledge .

I've never tried that. I don't fancy leaving a lens in the sun, drying out the lubricants and expanding all the components.

An intense blue light such as dentists use to cure composite materials might be interesting.

that's supposed to reduce yellowing !? and may help with fungus ??

tried it and it didn't work for me


John is against dismantling lenses to clean them, as they may need special equipment to reseat the lenses correctly !! Right John !?

John - I didn't say permanently

An hour won't harm and sunlight can clean up infections in other areas

I'm trying to remember who on here, took some lenses apart and cleaned them up very successfully

Many thanks, like I say I do NOT have the lens yet but if it can spread I rather not get it anyway.
I usually keep each lens in a soft pouch with a packet of silica gel that gets changed every month to prevent fungal growth on my lenses but like I say its my friends lens (Pentax A - SMC - 28mm/f2.. I was interested in it to use with my macro tubes, but I do not want to invite fungus in to my house and rather pass if it can contaminate other lenses.

Me but see comment above !

It's unlikely to jump huge distances to other lenses IMO.

You can usually remove it with vinegar on a cotton bud, providing you can get the lens apart. I've done this with three M 50mm lenses, a K 28-50mm zoom and an FA 80-200mm zoom, all cleaned up perfectly although they have rather more dust inside now (almost impossible to avoid). You'll also want a microfibre cloth, surgical-type gloves (check if you have a latex allergy) and a lens wrench/spanner along with a set of jeweller's screwdrivers. All are easy enough to come by.

I don't think you really need special equipment to reseat elements in older lenses. Newer models with lots of plastic do rely on specific torque settings from what I hear, but for K, M and probably A series you just need to make sure everything is properly settled (the right way around and in the right place) then tighten the securing rings slightly more than finger tight. I've been unable to detect much difference between the 50mm f2s I've cleaned up and the mint one on my K1000.

I personally think the old Pentax hard lens cases have a lot to answer for. Both lenses I own which came with their cases had fungus, and I suspect that the fact the cases aren't breathable didn't help. I usually use Lowepro cases with a silica gel bag tucked into the mesh pocket in the lid, lenses stored in this way have no such trouble so far.

Interesting. Maybe I just get the lens to 'play' around with it and if it does goes wrong at least I know that I should better leave my hands away from it.
I may just have a go if I get it cheap enough.

The ease of cleaning/destroying fungus is entirely governed by :-

1: How deep into the lens assembly the fungus actually is, and
2: How easy/difficult the lens is to dismantle.

If the fungus is on the inside of the front or rear element and the affected element is simple enough to remove, the fungus is easily cleaned.

If the fungus is between cemented lens elements forming part of a group, the lens is bin fodder unless it is really worth doing it, say to Unlocker's 250-600mm monster, for example.

Prime lenses are more easily disassembled than zooms, or rather, primes are more easily reassembled.

It is quite likely that you will need some specialist tools like lens spanners etc. which you can buy from Micro-Tools.

I have had fungus professionally removed from a Pentax-A 200mm f4, cost around £40. I will attempt to deal with more common lenses myself, but given that was both quite rare and expensive (by my standards) I felt it safer to let a pro sort it out.

The 28mm should be easy providing you can get the front element to unscrew. AFAIK it's mechanically identical to the later version of the M 28mm f2.8. I have one of those with some fungus and have failed miserably to get the finishing ring to unscrew (it has instead been slowly chewed up by my efforts), as the part is plastic rather than the metal found on earlier lenses.

The only modern lens I've tackled was a case of fungus on the rear of the front element. I simply unclipped the finishing ring, removed a locking ring and then unscrewed it before cleaning, reinstalling, resetting infinity focus (using an ME Super body on a tripod, as the split focus screen means you can tell when it's spot on while using a hill several miles away as a target) then reinstalling the locking and finishing rings.

The olny tool I am missing as far as I can see is the wrench, however I can see myself needing screws as I am a specialist in loosing them, no matter how safe I store them.

If you can go back away in the forum you should find that mowag not only cleansed a lens for me but put on the forum pictures showing the proceedure
This should give you a very clear idea of how to go about cleaning fungus.
I miss Mowag. He was so helpful.