Any suggestions on what to get from the chemist to shift those stuborn stains? I geuss pure alcohol will be in there somewhere??
Canned air; camel's hair brush. Look at surface obliquely to make sure all grit is off. Breathe on lens; use a brand new cotton swab. If this does not work. a drop of Vodka on another brand new cotton swab. Drink remainder of vodka AFTER cleaning lens.
I have IA-type filters on almost all of my lenses. And I remove them whenever I intend to take pictures.