LX FC-1 viewfinder problem

I have recently picked up a FC-1 viewfinder for my LX. Sadly, it has a slight fungus problem. I knew this when I bought it but the FB-1 base is in immaculate condition and it wasn't a bad price. Is there some way I can kill the fungus so it won't spread without taking the thing apart? Is it even possible to take the thing apart?

Many thanks, Kris.

Exposure to UV light will generally kill fungus (easier said than done in this country, but maybe take it with you on your next exotic jaunt ). Of course that won't get rid of the etching left by the infection - for that you'll need to get cleaning and that means getting inside.

Can it be done? Of course it can! If Pentax put it together then you can take it apart again...

I just remembered a suggestion I read somewhere in the week; to speed up the UV saturation cover one end of a lens (finder in this case) in tin foil and leave the other end exposed to the Sun - the UV light will bounce off the foil and reflect back so concentrating the exposure. Not tried that myself yet but sounds plausible in theory.

Could you put it under a sun bed?

I don't see why not - any source of UV should do the trick. I use window sills because the Sun's the only source I have to hand.

Actually.....,I was under the impression, this technique is used for de-yellowing old Takumars. And the tin-foil wrapping is only to prevent internal lubricants from melting during the sun bath. Fungus can only be removed with the aid of some sort of chemical process, if I am not mistaken.

Martin.

Hi. Thanks for the ideas. I am not bothered necessarily about physically getting rid of it, you have to turn the thing around in the light to see them and they are invisible when actually using the viewfinder. I just want to kill the fungus so (a) it doesn't get any worse and (b) removes any possibility of spreading to other kit. (I know that some have argued that it shouldn't happen as the spores are in the balsam glue but I'd rather play safe!) I'll look into the ultraviolet idea. We'll probably have some UV lamps in the lab at work.

Many thanks, Kris.

The UV idea is floating around there in webworld but I have found a couple of microbiologists who state that you need UV-C to kill fungus, and sadly glass absorbs most UV-C. Taking it apart and cleaning it seems the way to go. Anyone have a diagram of the inside of a FC-1?

You are and you aren't mistaken.

The fungus itself is microscopic and invisible to the naked eye; the spider-web-like patterns that you *can* see aren't fungus, but rather the secretions of the fungus. UV light will kill the fungus but it won't remove the secretions - to get rid of them you have to strip the lens and clean it (although I'd avoid the chemicals that some recommend as they'll take the coatings off too). If I have a lens where the secretions aren't making an impact on image quality then I'm quite happy to just kill the fungus and not bother with the cleaning part - unless it's got really bad there's a fair chance you'll do more harm than good.

Don't let them put you off. I haven't tried the tin foil technique but I will the next time I get an infested lens. A few weeks sat on a windowsill has always dealt with the problem in the past, by using UV lamps you'll just be speeding up the process. Even if the glass absorbs *most* UV-C it stands to reason that *some* (enough) must get through...