rdoc wrote:

I tried using my regular lens cleaner with only marginal success.

What can I use on the glass that will not harm the multicoating? Alcohol?

Modern lens coatings are not likely to come off in alcohol.

I would suggest dipping q-tips in either alcohol or Windex
and work gently, changing q-tips frequently. There should
never be enough liquid at the front of the lens that there
is a risk of some seeping inside, you can alternate wet
and dry q-tips. The real risk is scratching the lens or
coating, a little bit of grit can do quite a bit of harm.

A single big scratch is actually nearly harmless, but lots
of tiny scratches will ruin the definition of a lens. People
sometimes do make lots of tiny scratches, so be sure to change
q-tips very frequently, especially at the start.

Peter.
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