Spots on front surface of lenses---fungus?

[Steve Williams_812]

I have searched through the postings and cannot figure out what has happened to two of my lenses. I had them in my turck for a week in this hot humid weather, capped and wrapped in a Calumet lens wrap. I used them yesterday and while looking at one I blew some "breath" on the surface to see some fog and there were several small circles on the coating. When the fog disappated in a few seconds I could see nothing on inspection under a strong light, no evidence of marks or fungus inside the lens.

I tried cleaning these things but no apparent change to them. They are definitely on the outside, almost like some incosistentency in the coating but I am certain I would have seen it before.

Any ideas on what this might be or what effect it will have?

thanks,

steve

[Steve Hamley]

If you have to breathe on it to see it, none. There are several good reasons not to keep lenses in a hot humid vehicle.

Steve

[Bob._3483]

If it takes condensation to show it up, I would suggest the most likely cause is oil. I know you cleaned them, but depending on how you did it, it may not be enough. Try using the Opti-clean polymer which will remove just about anything from the surface of a lens. If the marks remain, then your guess is as good as mine....

The fact they were in the truck for a time just before you noticed the problem may be a red herring. The other thing I was thinking of is pressure marks from the lens cap being pressed down on to the lens surface and leaving a faint mark that way - depends where the marks are.

Other possibility: faint salt marks from water drops evaporating from the surface: even rain water is not as pure as some would have us believe - that may not be removed by normal cleaning as the crystals would need to dissolve first.

That's all I can think of...

Good luck... Cheers,