Hi All
It was only in the past few days I have had nice blue skies to get soem decent dust check images and would offer the following observation.
Previously with grey/cloudy skies even defocused I was seeing sensor marks (dust or whatever) that a rocket blower would not shift Note this was using Auto levels to 'reveal' the dust and its locations. The dust was even showing up at f9
Well, now to the point of this post. I took a series of sky images at all apertures down to F32.
From f16 I could make out a couple dust spots when the image was viewed at 100% then count increased only slightly at f32 but with auto levels the whole bunch of a couple of dozen appeared. I think at f9 I could just about make out one when viewed at 100%.
So, do we ever use auto levels in normal PPing (I never have done that). And how often do we use a crop taken 'out' when zoomed at 100%. In other words for most folk I surmise dust should not be an issue and for the odd spot that appears over time a simple clone out should suffice & a dry and/or wet cleaning method (whichever 'you' are comfortable with) should remove the offending item.
For myself I will be getting either Canon or Fixation to give it the 'under warranty' clean and then use the rocket blower as needed but based on the above I certainly will not (I hope 
) be sweating it about the dust because as I understand it I am very unlikely to see much if any dust in the airshow shots I will take because I think the smallest aperture I have used is f11 to get my shutter speed down to get prop blur.
For the record, as mentioned in another "subject" related thread, my 350D shows no dust in such normal usage and that is after two years.
The above are quick thoughts based on a rapid look at the images and I will be reviewing them again to confirm my thoughts & observations.
Have I made sense or totally lost the plot 
Incidently, I notice when reviewing my sky images in Bridge there were odd circular 'diffraction like' patterns visible but once opened in CS2 they had disappeared - anyone seen similar and know why this happens??? Could it be that Bridge is using a thumbnail as the viewable image and as such this will show such artifacts under bright sky images?
