I've noticed some spots on some pictures that I've taken. Is this dust on my sensor or something on my lense? My camera is a 30d that I bought new about 3 months ago and the lense I was using is my new Tamron that I got about a week ago. Here is a pic. Its an HDR. You can see the spots in the sky. Thanks. ***UPDATE**** I tried taking some pics with my 50mm lens and the same spots show up! This means I have dust on my sensor correct? Can I clean this myself or is it better to take it to a camera shop and have them do it?