So I thought that maybe this Sigma lens isn't cut out for the job. However I tried my canon 24-70 2.8 EF lens but that does the same. I'd like to point out though that it seems to happen more often when it's a wide angle shot. It happens a lot less when I zoom in.
So, is the Canon Rebel just not that great of a camera? Do I possibly have sensor issues? Should I only be using Canon EFS lenses with the Rebel t2i? Is my hand shaking more than I think it is? (the latter I don't think so).
By the way, video seems to be just fine with both lenses.
So you definitely don't have an enormous smudge on your lens?
Perhaps inner lens condensation is prevailing. This happened to me when I first got my T2i/550d - it was freezing weather and when it came the camera was just as cold and the glass was all condensation.
You don't store your camera in the freezer, at all, do you?
Other than that, I don't have a clue!
Amateur Writer, Director,
Director of Photography