Sun 10-Jun-12 06:51 PM | edited Sun 10-Jun-12 07:01 PM by ZoneV
The best way to keep the camera level when shooting sports is practice on your own time. Hold the camera normally, and practice panning at various speeds while keeping it level. Then try to flip as quickly as possible to vertical orientation while rotating exactly by 90 degrees, or as close to that as you can get. Keep practicing these maneuvers, and eventually you will get 95% of your shots within 2 degrees or so of correct orientation.
This is one of those situations where a pro body...with its square shape, good grip, bigger viewfinder, well balanced mass, and vertical grip can really help out.
It also helps to remember that the viewfinder is not just a window you're viewing through, but actually a representation of the final scene, with its borders and orientation.
If it helps, you can also enable the viewfinder gridline feature. Personally, I tend to just go by feel...I can tell when the camera is roughly alinged properly. I shoot very quickly, especially in sports. My camera is almost never still, always panning, and I sometimes even will run up and down the slideline as fast or faster than the players, in order to better follow the action on certain plays (in order to have maximum mobility I shoot with one body, I don't use a monopod, and typically use a relatively compact lens--a 300/4), but I still get the majority of my shots aligned ok. I rarely have to rotate the frame in post. Practice!!