I bought this camera some time back and I noticed some spots on my pics. I figured it was a dirty lens, then I noticed it again and thought I forgot to clean the lens so I forgot about it. Now, I've switched lenses and still get the spots in all my pics. One is a spot the other is a horseshoe shape. Is this a dirty sensor or something more/worse? Also, would a decent camera shop clean it for me? Or should I just do it myself? I cropped the pic to just get in the spots, lower left and upper tight corners.