In article <31456A7D.41C67EA6@etlxdmx.ericsson.se>, etlndh@etlxdmx.ericsson.se says...
> I was slightly over zealous with the cleaning fluid
>on my Nikon 50mm F1.8 E-Series Lens. Subsequently, you
>can now see on the inside of the first element (in the
>light path) a smear of multicolours where the fluid has run
>down the lense (you have to hold the lens at an angle
>to see it though).
>It looks a bit like car oil does in puddles
>of water. When you look the through the lense to take a picture,
>you really have to look hard to see it.
>What I want to know is -
>1) Has it corrupted the lens coating ?
>2) Is it worth having it cleaned ?
>3) Has anybody else had this problem and if so
> what did they do about it ?

I would not worry about it - it will have little, if any, effect
on photos. Given the price of a good used 50mm E lens, sending
it out for cleaning is probably not cost-effective. If you are up
for it, you could try to unscrew the front retainer (there may
be a tiny hole in the side of the front with a set-screw in it
which can be loosened with a screwdriver made by filing the end of
an unbent paper clip) to see if you can get behind the front element
(probably not easy, since you may wind up with all of the glass,
or the front 3 element section, in a chunk, requiring further
disassembly) - hmmm, better forget disassembly, and just use it
(and consider it a relatively cheap lesson).
Hope This Helps