[ytterbium]

Is it safe to use occasional UV exposure as a fungus prevention measure on lenses i don't use often.
Something like 1..2 minutes for back and front element every month or two.

Has this been discussed somewhere i couldn't find?
(Search returns only fungus or UV filter posts :/ )

What kind of UV light type do you recommend. Black light (im guessing minimal disinfecting effect, only visual effects), UV for photochemical stuff (white matte tube, like in solarium, PCB exposure) or bactericide UV light (clear quartz tube, used for disinfecting, make ozone, might damage coatings).
What power do you recommend? Right now i own 3*8 W UV light (~300-400 nm).
Does it have any effect at all?

[Rykoh]

I had the same thought once, but couldn't find a UV setup that was cheap enough to make it worth experimenting. I'm interested to see what people say.

[ytterbium]

Well, it is not expensive to get simple bulb (like THIS) from a zoo store, that fits in a standart screw socket and puts out a ton of watts. I guess their intended use is for some desert species?

But even then there are numerous options (for aquarium, for snakes, for scorpions), having different power ratings and light spectrum. So you may get all kinds of results.
I've used some stronger (~500w), shorter wavelength UV lamps wich could be very effective in destroying any kind of bacteria or fungus, but made crack like pattern on transparency and printer ink within seconds;
http://foto.inbox.lv/kilovolt/PCB/image011.jpg (Fixed link)

[Tom S.]

I had the same thought once, but couldn't find a UV setup that was cheap enough to make it worth experimenting. I'm interested to see what people say.

Your run of the mill fluorescent light gives off uv rays.

[Bactman]

The most effective way to prevent fungal growth in/on a lens is to limit moisture exposure. The initial moisture load to initiate germination from a spore is high (think 95% or so), and this must be sustained for 36-48 hours. From there, less moisture is needed to sustain hyphal extension and eventual sporulation (species dependant).

FWIW - many spores are inherently resistant to UV light exposure. We did use general UV light kits for disinfection in a lab I worked at some time ago, but that was for bacteria, not fungi. If you decide to fry your lenses with UV light, make sure you wear a glove or some protective coating on exposed skin so you don't give yourself a sunburn.

As for the UV's effect on the coatings, I have no idea.

[Tom S.]

And don't forget to take off your UV filter...