P.S. If you do have a lot of finger oil on the lens, you might try one of those oil-removing skin wipe things. In my area you get a pack of 10-20 blue, thin sheets in a little pocket pack, they are meant to be used for wiping the oily parts of your face. Anyway they "grab" oil fantastically well and what minor powdery stuff is left can easily be brushed or blown off. These sheets can take oil off lenses and rc prints too. I don't know what's on those pads but my suspicion is that it is forensic technology- you can lift fingerprints very easily with them!