So I'm no stranger to dust in lenses. My very first lenses were all zooms with extending barrels so dust isn't that uncommon. As far as I know, even weather-sealed prime lenses can get dust inside the lens. My 100mm L Macro that I lend my friends to use almost every other month has a fair amount of very fine dust that is visible only on close inspection. Most of the time this is alright since the dust doesn't show up in photos anyways. It doesn't bother me but for others, that's a different story. I'm curious to know, are there any methods to reduce the amount of dust getting into lenses if I don't shoot in clean rooms all the time?