where I would be rattling somewhat

A deep-field landscapey thing with a lot of sky in would be a more likely candidate for revealing sensor dust, but I was fiddling about with sweeping slow-shutter pan things at the bicycle races around the Grassmarket on the way home and therefore pinpointing the offending specks with my smallest aperture. It'd have been interesting to have been in time for the start of one of the races to see the difference in the speed at which Victoria Street was taken between the first and last laps.