completely normal. Every DSLR sensor suffers from this to some extent. I'm sure Neuro or someone like that could elaborate a bit more than me on the exact reasoning why. Probably have a dead pixel or two as well, you usually won't notice those until you do a really long exposure and those will be bright red.


A way to counter act this is to employ image stacking using software like DSS (deep sky stacker), which is free. There are some pretty good instructions to get you started in the help section. One thing you do to counter this specifically is to take "dark frames", basically taking 10-20 pictures with your settings the same and with your lens cap on right after you take your photo, while the sensor temp will be similar to what it was to take the photo.. Essentially you're taking a picture of your camera's noise. The software then uses the dark frames to subtract the noise from your "light frames".


This is a gross generalization, but that's the gist of it. If those spots don't appear with short exposures at lower ISO, I wouldn't worry at all.


p.s. Like the framing of these. you should give 20-30 second exposures a try. You'll probably find some stars in your frame you didn't even know were there. []