Following recent trips, my camera optics have acquired an assortment of dust and marks. Changing lenses in (considerably) less than sterile environments doesn’t help. Most annoyingly, near the start of the Egypt trip, I acquired a mark on my sensor ((okay, technically on the low-pass filter, pedants)) – at least I assume that’s where it is, though when I lock up the mirror I can’t see anything. I need to buy some proper cleaning implements and spend some time giving everything a once over.
In the meantime, I have many nice shots that have a dark smudge near the top-left corner; it’s only visible on areas of flat colour, which basically means sky. I hoped these would be easy to re-touch (I’ve done similar things in iPhoto in the past), but couldn’t immediately find how to in Aperture. A few minutes exploring turned up the ‘retouch’ adjustment:
Without changing any of the settings (but looking rather sceptically at the ‘automatically choose source’ checkbox), I waved the brush over the mark, and, well, voila:
Whatever the source selection criteria are, they work well, even when the mark is close to a feature. And there was much rejoicing.
Looks very much like dust on the sensor to me. Last time I had this I gave my camera a damn good puffing with a Giotto rocket and it went away.