Ltgk20 wrote:
I've never had much of a problem on my DSLRs or my mirrorless (all Sony), but try to be careful (camera off, pointed down, not too dusty an environment). I also choose not to have my shutter close when changing lenses as I feel the shutter is more susceptible to damage from potential external forces than the sensor is.
If you have fast lenses and tend to shoot wide open you may not see the dust.