As I went past four weeks from my knee surgery, I was finally able to get outside without a crutch (still limping), and I felt able to tote the 500/4 lens outside, for this picture and the three others taken this day. Conclusion -- the 400/5.6 lens, which I've been using up for these deck photos, is a really fine lens, but the 500/4 is even better. More awkward to maneuver on a monopod while sitting on a stool, though.