We're going on a dust bunny hunt ....
My trusty old Canon 50 D has a dust bunny which does not want to be dislodged with either a blower or the in camera sensor cleaning.
I bought some cleaning swabs and fluid a while ago but have waited until I had the opportunity to buy an inspection magnifier. I can see the offending dust, just need to read up now on how to remove it without doing any damage :-)
Perhaps have a first attempt on my old 350D which has never been cleaned since being bought back in 2007 :-)
Four images focus stacked together in Helicon Focus.
In other news: I have thrown caution to the wind and ordered a Lee Landscape polarising filter .... the sky will now be leaden for at least a month!