Fungus attack.


Link Posted 25/07/2011 - 20:25
I've had a disaster and I'm looking for advice. For various family reasons that are unimportant in this context I've not had access to my lenses (apart from the two I use as 'walkabouts') for more than two years. I finally got to the two drawers they were stored in today and there is mould and fungus in there. Some damp must have got in, I guess. A few of the lenses look OK, but some of my favourites - KA 35-105, KA 70-210, M 50 1.4 have some spider web patterns inside. (no blotches, just small patches like fine hairs)

Can anyone suggest what measures I should take? I'm guessing all the lens cases, camera cases should either be cleaned or thrown out? Is it likely to do any good just putting them somewhere dry and warm? If the lenses need pro cleaning, how much is that likely to cost?
Last Edited by redbirdpete on 25/07/2011 - 20:27


Link Posted 25/07/2011 - 20:32
UV light kills the fungus IIRC and a service is likely to cost 40 or so per lens...

my pics: link
my kit: K3, K5, K-01, DA 18-55, D-FA50 macro, Siggy 30/1.4, 100-300/f4, 70-200/2.8, Samsung 12-24/f4, Tamron 17-50, and lots of other bits.


Link Posted 25/07/2011 - 21:26
Professional job I'm afraid. Apart from the KA 35-105 it would probably be cheaper replacing them

UV light only removes yellowing from a lens.

All the cases are better thrown away.

I've just bought a lens with bad fungus on the rear element and nothing I've tried so far will shift it. I've ordered some Pond's Cold Cream off ebay to see if that will. If it doesn't I might have to try polishing it off with cigarette ash circa 1910
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff



Link Posted 25/07/2011 - 21:38
You can probably save the M 50mm yourself, assuming the f1.4 is anything like the f1.7 and f2 versions. I managed to clean similar fungus from a couple of cheap ebay finds which has yet to reappear after a year or so, and they seem fine optically.

I found plain vinegar on a cotton bud worked well to clean the spidery marks off. You'll also need a lens wrench (look on ebay) and a microfibre cloth to polish the elements after cleaning with vinegar. A pair of surgical gloves can be handy to avoid getting fingerprints inside the lens while reassembling it. To be honest the hardest part is usually unscrewing the finishing ring (where it says "SMC Pentax-M 50mm f1.4" around the front element) as they often seem to have been tightened with a torque wrench and won't unscrew! Have a look on the web for some disassembly guides, what I will say is that you don't need to disturb the focussing mechanism on this lens while removing all the elements, so you won't have to fiddle around resetting the infinity focus afterwards.

I have a deep distrust of the leatherette hard cases Pentax offered for most of the older lenses as I suspect they trap moisture. I've had two lenses in said cases, both had or have a mould problem. Meanwhile my other K and M lenses in Lowepro soft cases with a bag of silica gel are fine.

Shooting the Welsh Wilderness with K-m, KX, MX, ME Super and assorted lenses.
Last Edited by Dangermouse on 25/07/2011 - 21:39


Link Posted 26/07/2011 - 08:24
OK, thanks for the responses. My lenses were in soft cases, which I think helped to collect the damp. Probably they should have had silica gel in, but that's the way I've been keeping them for years, previously, though, I'd have had them out every month or two to check them, and in any case the two zooms would have been used fairly regularly. Nice though the 50mm is, its years since I used it so I might try cleaning that one myself.

I'll think of some other way of storing them for the future.

It's typical that some of the less useful lenses seem fine!

Has anyone got reccomendations for places that do professional cleaning?


Link Posted 26/07/2011 - 09:37
Professional cleaning: link

Storage: Screw-cap or snap-lock tupperware containers lined with adhesive-backed Fab Foam with discs made of the same in the base and lid to provide cushioning and prevent 'rattling'. Lenses stored in the presence of self-indicating silica-gel having first ensured they are at room temperature and wiped dry with a microfibre cloth if used in the rain.

For very large lenses (e.g. Sigma 100-300mm f4 EX DG),I use the supplied lens case and industrial quality zip-lock or seal-easy bags, as tupperware containers of this size are difficult to find.

Works for me

karma mechanic

Link Posted 28/07/2011 - 08:39
Coincidentally I just had a flyer from 7dayshop, which shows an offer on silica gel:
My own website is

Also on 500px
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