Lens fungus ??

[Rookie 300d]

Hi, I hope someone could help me. I am currently selling a lens on E-Bay and have been asked if it has any fungus in it. What is it ....what does it look like and where do i find it? If it has any at all.

Thanks
Paul.

[Chris_Johnstone]

I think they are asking about its condition. Is there any dirt or grime in the lens? That kinda thing. Otherwise they're insane.

Chris

[Boddie]

Yes, its possible that through condenstaion a fungus can grow internally. Its usually quite evident, and if you cant see any, they wont

[Wilf]

Lens fungus appears as fine wavy lines over the surface of one of the elements. It can be very expensive to have it removed.

[Hobjob]

Originally Posted by Wilf

Lens fungus appears as fine wavy lines over the surface of one of the elements. It can be very expensive to have it removed.

Sometimes just grey smears too.
Easily seen when lens is off the camera and look
from the camera end. If that test is OK, then say
to the ebay buyer guy "no visible fungus" or some such.

I have a simple 50 year old spotting scope which was
thick with it, even between two lens that were in contact
- took the thing apart (it was very simple
design) and cleaned with glass cleaner and its come
up amazingly well - works fine as a second scope when
out with two people.

On a modern complicated lens, as Wilf says, will cost
a bomb to disassamble and clean.

[HowlinWolf]

Rookie 300d,

A fungal infection is usually the kiss of death to a lens. The spores will etch the glass, usually attacking the multi-coating of the elements as well as the cement holding some of the element groups together. It is usually the result of lenses being used in high humidity conditions and not being allowed to dry out after use (or not being allowed to dry at all). Poor storage can also result in fungal growth when cool, dry air is not allowed to circulate around the lens. Adding a sachet of silica-gel to a camera bag can help eliminate these problems. At a pinch, uncooked rice can be used, but its effectiveness is reduced around ten fold.
If lens fungus is caught before it has had a chance to contaminate the whole surface of a lens element, exposure to ultraviolet light has been suggested as a fix by some people. Removing the UV filter (if fitted) and allowing the lens to stand in sunlight for two or three days is said to kill the fungal growth. I've never had the necessity to try this, but apparently it works.
One thing to bear in mind with all this is cross-contamination: keeping an infected lens with other optics (i.e. in the same bag) will allow the spores to migrate from one lens to another. In the same way, fitting a lens with fungal growth to a camera can allow the spores into that body, infecting any subsequent attachments, as well as the mirror, sensor (in the case of digital SLR's) and focusing screen.
For what they cost, silica-gel sachets are a good investment, but ultimately the best solution is use that lens, and treat it nice.

HW

[Rookie 300d]

Thank's to everyone's comment's Im well sure it is clean of any fungus.

Paul.