I just got a Canon 400mm 5.6 L. What I am wondering is what kind of aperture I should be using for birds and wildlife. I don't understand how people can shoot wide open. Isn't that too shallow of a DOF to get any kind of good bird shots?
I have also wondered this about the pro lenses that have max apertures of like 2.8. I don't understand how someone would pay so much for a crazy big fast lens like that- how can 2.8 be usable for wildlife? Why spend $10,000 for an insane lens that is so fast- do they really shoot at 2.8 so much? I may be missing something....
In fact this just occurred to me...with a huge pro lens stopped down a bit, for example a 2.8 stopped down to 5.6 or 8 or something, would that aperture still be "bigger" and let more light in than my lens at the same aperture? Not sure if that makes sense.
Thanks for any help