After 6 months and 10k shots, my D750 sensor have more than 100 oil spots (I shot landscapes at f11 and they are very noticeable), mainly distributed along the right side of the sensor (when seeing a photo). I never changed my 28-300 and this is absolutely abnormal to me. I owned a Canon 60D for several years, more than 200k shots, normally changing lenses, and never have this level of dirtyness. Any other user of this camera with the same problem? Thanks!