Silhouette photos - always fun to do, especially with such a spectacular coastline sunset at my disposal! I'd just finished a different set of photos involving chasing small boys who were darting in and out of the water and flinging sand around. I was aghast to find that I had a salt-water flecked dirtied lens (lens filter, to be more precise - a protective circle of glass that covers the lens) and that little specks dotted ALL of my photos. ARGH. I will have a lovely time editing all of that out of my kid pics.
I took the major specks out of this pic. They wery very obvious against the light sky. I thought about taking the lens flare out (the 2 light dots) but decided to leave them. Looks less polished this way.
I went home and cleaned my lens filter using a glasses cleaning kit. Have to make sure there are no sand bits before wiping otherwise I could drag a sand particle around the glass and that wouldn't be helpful at all. I took some test pics and some dots were Still There. It turned out that my sensor was dirty, and that's a part of the camera that's deep down in the depths of the camera body, never exposed to the light of day except through a lens. No idea how it got dirty.
To access the sensor, the camera lens mus be removed and the settings placed on indefinite exposure (go to Manual settings, change exposure time to "bulb", press shutter down for as long as you want sensor exposed). Doing this, I delicately q-tipped 2 dots of sticky dust off the sensor (looks like a little reflective rectangle). All is well again. Whew.