About 6 months ago I purchased a Sigma 170-500mm F5-6.3 APO DG lens, my first super telephoto lens to get me started.
The lens is quite old and doesn't have a lock switch to disable zooming (the lens extends and contracts as you zoom in and out).
The lens is quite heavy and will extend fully under its own weight if I'm not holding the end. This can be a bit problematic while walking around with the lens because I always have to be holding the end of it to prevent it extending, which after a while does cramp my wrists a little.
But my question; does walking around with the lens fully extended actually do it any damage?