Eventually it will probably happen even taking every precaution to reduce the chance of dust on the sensor. Did a quick search here at mu43. Bit of info regarding the "copperhill method". Reading HDR thread & the link to Jason Odell review I linked to a commercial site: PhotographicSolutions. Anyone use their Swabs and Eclipse solution? What size swab (17, 20, 24mm) would be the better size for the GF-1 sensor?