They got back a Canon 70-200mm f/2.8 IS II lens from rental, and found a fly inside the lens. A lens that’s supposed to be weather-sealed. While it is still unclear how the fly managed to crawl into the lens, Roger Cicala shows and proofs that a fly inside a lens (or dust for that matter) has little to no effect on image quality. He also shows how difficult it is to remove the fly from the lens.
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