Hi Bob, It's almost certainly not beneath the filter - if it's right against the sensor then changing the aperture doesn't make it disappear (it's the distance between the dust and sensor and the lower angle of the light that makes the dust disappear as you open the lens aperture).
Depending on what the tech did at GFM it could be a stubborn bit of dust or a faulty filter (I had one, it manifested as a fine spray of dust and was visible only above f11 - fixed under warranty by CR Kennedy Australia). A check by Pentax would be my suggestion. The dust find function only closes the lens to f16 for the test and ignores anything below a certain size (not sure what it is). It's useful as a check if you are mainly shooting portraits and other images with fairly wide open aperture, but if you close down the aperture a lot then using the highest aperture on your sharpest lens and examining the image is the best way to find dust. Hope this helps Leon On 11 June 2010 23:23, Bob Sullivan <rf.sulli...@gmail.com> wrote: > Rob, > I've tried the dust detect function and it shows nothing - a white > screen mock-up of the sensor. > I'm afraid of something beneath the filter assembly and the trouble of > replacing the camera. > Thanks for the suggestions as to cause. > Regards, Bob S. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
