Eugene wrote:
I was experimenting with a couple of night shots outside and got speckles in
the sky. Is this dust on the mirror/sensor. What do you recon ? Heres the
link to one. http://www.pbase.com/image/73613356

Probably not. The classic case to show dust on the sensor at its worst
is an exposure of a bright field like the sky, stopped way down (like
f/22). What you've got is pretty much the opposite of that, so if it
*is* showing dust you've got an entire dust-bunny! But other people's
suggestions about what you're seeing sound reasonable to me, too.