Fungus, what is it ?

Morrisseeee

Having 'borrowed' a Film kit from someone, I found that their 50mm lens has some markings/white-trails/fungus? or something in it. See pic below, or larger in pix.ie, its not very clear (I'll get a better pic tomorrow !).
But......what it appears to be is.......like white streaks (like snail trails!) on the inside of the glass. Is this fungus ? or what might it be ? and can it be cleared up ?
I get the impression that the person who owns it doesn't know about this (fungus) ! which means I don't think they'd be bothered in spending money cleaning an old lens, you'd pick up one on eBay cheeper. So, can I clean this mess up for them, or is it a lost cause ??

Morrisseeee

Here's a better pic:



It looks nasty, I doubt if anything can be done !

CabanSail

To me, that looks to be on the face of the front element of the lens & should clean off OK.

Fungus is normally a problem on elements within the lens & requires it to be dismatled to be cleaned.

stcstc

if its fungus, do not put it anywhere near your other gear

it will, ruin your other gear

Morrisseeee

that looks to be on the face of the front element of the lens & should clean off OK.

.....thats what I thought, but after trying to give it a good clean, its still there. It looks like its on the inside of the glass.

do not put it anywhere near your other gear

....don't worry, it will remain well clear.

I was reading up on fungus, and it needs certain conditions to grow, humidity etc, I'm just wondering if I keep it in a warm well ventilated area for a while will the fungus die away, or are the marks permanent ?

/Note: its not a major issue as I have another 50mm (should the owner need one), but I don't think the owner of this kit will be too bothered eitherway !!

CabanSail

Morrisseeee wrote: »

.....thats what I thought, but after trying to give it a good clean, its still there. It looks like its on the inside of the glass.

It could be a growth under the coating on the front of the element. Have you tried soapy water or an alcohol wipe?

Morrisseeee wrote: »

I was reading up on fungus, and it needs certain conditions to grow, humidity etc, I'm just wondering if I keep it in a warm well ventilated area for a while will the fungus die away, or are the marks permanent ?

Once the fungus has grown it will leave the marks.

Morrisseeee

mmmmm......I may be able to clean it, well at least get in at it, ie. I've just taken apart an old Centon 50mm lens and at least I now know what to expect !



^^ taken with camera phone !

Note: I wonder what would happen if I put back one of the elements/glass the wrong way ????????? Tilt-shift !

cnocbui

The idea of keeping it away from your own gear to prevent 'infection' is an absolute laugh!

The amount and variety of fungus spores naturally in the air makes such a precaution almost totally pointless.

Fungus left long enough will etch the coatings and glass itself, so cleaning might not yield a 100% cure or improvement. UV light kills fungus, but glass blocks it a lot, so exposure to direct sunlight for a good long time wouldn't hurt.

Irelands constantly high humidity is a real problem for lenses. I keep all of mine in two Pelican airtight cases containing multiple sachets of silica gell, which I recharge in an oven twice a year. I stuck a radio transmitting hygrometer in one just to see what the humidity was like after closing the lid. After 20 min it was down to 12% or so. It probably gets lower than that with more time but I haven't bothered to find out.

I doubt a mildly fungused lens would result in observable image degradation except in shooting situations where flare would be an issue.