We perform all of our conversions in a dust free ISO Class 5 clean air bench to eliminate as much airborne dust as possible. To make sure the filter we install does not have dust, we also employ a rigorous cleaning and inspection process, where the glass and sensor are inspected under a high magnification microscope before being installed, and again testing for dust once the filter is sealed with normal test shots, allowing us to come as close as possible to a dust free conversion.