Last Friday, I shot this panorama from the building where I work.
Raw, f/5.6, ISO 400, using a polarizer and a graduated filter. Compared to my earlier panorama attempts -- hand-held camera and no filters -- this picture sucks. The sky is noticeably grainy at 100% resolution, and you can see obvious vertical bands where the photos were stitched to create the panorama.
What caused these problems? I'm inclined to think it's the filters, because they're the major difference from previous attempts. As a matter of fact, I quickly discovered that the filters were wreaking havoc with my camera's autofocus -- unlike all previous attempts, I had to disable autofocus and shoot this with manual focus.
This is a classic example of how better equipment does not assure better photographs. :-(