Fungus on a Lens

[David Holden]

Fungus? What causes it? Can it be prevented? Can it be repaired?

 

[Canon Bob]

David,

Have a read of this to give you a little background.

http://www.mypentax.com/Fungus.html

Bob

 

[RobertP]

I did read up on this when I was tempted once by a cheap lens on ebay. Only internet facts so could be complete rubbish....

The fungus attacks the coating not the lens itself and starts off when the the lens stays damp for some time. It actually destroys the coating so cannot just be cleaned off. Repolishing and recoating is possible but too expensive. Saw comments that it can spread to other lenses kept together and others comments that it does not. Dry storage seems to be the best way to prevent it.

I decided at the time that it was not worth the risk for a cheap lens to buy one with fungus.

edit: looks like a better answer above ^^^

 

[oldgit]

Interesting read CB. Learn a little every day.

 

[David Holden]

Thanks All.

 

[trip]

i managed to rescue an old 135mm 2.8 m42 lens a while back. about an hours work with a small screwdriver and a lenspen.

it had fungus on two of the internal elements and a bit of dust.

i think it all depends on how bad it is. it covered about two thirds of the element in mine and now you cant tell it was ever there.

 

[ed_o_brain]

Paranoid now!

Reading the article, it says you shouldn't leave yourlenses in your kit bag - but I had left mine in there thinking that they would probably stay drier!

I live in an old cold damp house at the moment. (Hopefully not for much longer). I'm thinking of buying something to dehumidify my room but I'm wondering what else I could do?

 

[daftbugga]

sachets of silica gel can help,as found in the box when buying video recorders ,cameras e.t.c can be purchased at chemists , i keep 1 in my camera bag at all times.

 

[fracster]

sachets of silica gel can help,as found in the box when buying video recorders ,cameras e.t.c can be purchased at chemists , i keep 1 in my camera bag at all times.

...likewise, or get the bigger bags from your local sofa place,all the imported sofas have larger bags in them.

 

[sprog]

I learned that zoom lenses are most susceptible to fungus as zooming in and out draws damp air inside the body of the lens when you're outside. Top tip was to dry the lens by zooming in and out a few times when you get back indoors to expel most of the cold damp air.

Silica gel or dessicant is o.k. but it needs to be replaced regularly otherwise it actually retains moisture and can make the problem worse.

 

[joxby]

doh.....:bonk:

dont let anybody buy you a bargain..