Whenever I try to do a time exposure longer than 5 seconds with the noise reducer on the camera will close the shutter and shut itself off. when I tirn off the noise reducer it works fine. I also just shot some lightning today and all my pictures had spots like larger than noise like spots on the picture all in the exact same pattern on every picture. could this be a dirty ccd sensor? I dont think its a dirty lens. it also might have been too fine to be water.