> I think tomorrow that I will > take my most recent lenses (acquired mostly thru ebay) > in to the store to make sure they are clean.
Steve, Don't bother. Just spend some time with your lenses and a flashlight in a room with subdued ambient light. Shine the flashlight through the lenses and inspect them carefully, looking especially at the edges, and at the "dust." Sometimes fungus is very obvious when you look for it--it looks like black cauliflower coming in from the edges. The beginnings of certain fungus, however, can be hard to spot. It looks a bit like dust, but in the shape of tiny eyelashes--and often these will be distributed throughout the lens, not just on one element, or fairly evenly around. If you catch a lens with this kind of fungus, it can be cleaned and used again. After it is cleaned, if the aperture can be opened, leaving it where the sun can shine through it may help keep the fungus from coming back. You can also store the lens with a dessicant, and I hear that you can also store them with a fungicide of some sort, although I don't know what such a product would look like or where to get it. However, it's difficult to clean a lens thoroughly enough to get all the spores, and the fungus will re-appear eventually. Fungus can also look like "crazing" or like very tiny random spiderwebbing. All lenses have dust in them, so this isn't a cause for alarm. Real dust will often reflect as whitish, though, and fungus will look darker, even black, with light on it. Just be on the lookout for that eyelash shape. Some lenses have "separation," where the adhesive that hold cemented elements together is coming loose at the edges. This will usually reflect as whitish as well, and look like what it is. This is really nothing to worry about, because you're not using light rays from the very edges of most of the elements. Sometimes if you are given a "great deal" on an older lens, especially a valuable one, it's because someone has seen fungus in it and is hoping you won't. It's pretty amazing what some people can miss--I've seen lenses sold as perfect that had very obvious great black blooms of fungus on the march inside them. It's not worth messing with IMHO. Never buy or accept a lens that has fungus problems. They're more trouble than they're worth. --Mike
