In article
>I just purchased a used Tamaron SP 90mm/f2.5 macro and in the back element
>of the lens I noticed that some of that the coating has come off in a tiny
>spot at several places. These are all less than one millimeter and can
>only be seen when I hold it at a certain angle agains the light.
>
>There is an area that is also 1 mm or less that is circular and it seems
>like a drop of something came in contact with the lens but I can't seem to
>get it off. This also disappears when I look through the lens at a
>straight angle. I hope this is not a lens fungus.
>
>I bought a 55mm/1.4 used prior and had tiny flecks where the coating seems
>to have come off but I don't see any problem with the pictures and I am
>very happy with the lens.
This is probably spit (it leaves mirror-like spots on the coating).
Rubbing LIGHTLY with an alcohol-dampened (not soaked) Q-Tip, followed
by clean Q-Tips with breath (upward onto the surface, to avoid more
spots!) to finish, will probably remove the spot.
Hope This Helps