Hi, just purchased a new canon 70d body. after the first few shots I noticed a dark spot in the upper portion each photo. OK, dust on the sensor, maybe when putting on the lens, i get it. I have had my share of dslr's over the years, so i know what sensor dust is. Just take my rocket blower and all gone, never a issue.
So after noticing the the dark spot, i took out the blower, blasted a few times, reattached the lens and shot. Guess what, dark spot still there. I put the camera in manual cleaning mode, mirror lifted and the exposed sensor shows no dust that can be seen with the naked eye.
My question is, could it be something other than dust causing the dark spot, it only shows up against the blue sky, which i shoot a lot of landscapes. Should i return the camera in exchange for a new one.