High I'm looking to invest in a new lens for birding. It's either the 500mm or the 600mm and I'm just after some personal experience with either or both.
I know IQ is exceptional on both lenses but I'm more interested in things like, at the closest focusing distance what size objects(birds) are going to fill the frame and is minimum focusing distance and issue. Are you too close too often for it to be a concern?
Your thoughts would be most appreciated
p.s. Personal experience is what I'm chasing. I can read all about them on the net but I'm after your thoughs.