Interesting discussion here. Personally - because I can - I wash my lenses with Milli-Q ultra-distilled water (18.2 ohm resistance) with approximately 0.1% Nonidet P-40, a very mild non-ionic detergent, applied using a Pec Pad. I then rinse with pure Mill-Q water. I usually do this in a cell culture filtered-air hood to keep any dust out.


Of course, this is absurd overkill, but it amuses me and it is a pleasure to see the glass shining as good as new. Naturally, once out in the real world, the glass collects the usual atmospheric clutter that has absolutely no discernible effect whatsoever on my images. []