I spent a good hour today moseying after some azure-winged magpies. We had a nice waltz across a parkland, they rarely letting me get close enough to even contemplate a shot. As such, I spent long stretches (~10min) with my Nikon DSLR on but not in use.
And then I began wondering about power drain in such situations (switched on but untouched), and how different that status actually was from off, and after what period of time it makes sense to go ahead and switch the camera off?