Oh Dear Lord, Don't Let Ernest See The Video
Nikon video advertising their new fluorine coating in the front surface of their lenses.
Water, ink, paint, mud, magic markers, old engine oil - all dripped onto a glass surface. One half of the surface coated with the fluorine, one half not.
Watch and see what happens.
Just don't try to do it at home. And don't show the video to Ernest.
Note: They did not show wasabi or teriyaki sauce in the advertisement. Is this significant?