100-400 in spring?

TomFid wrote:

ijm5012 wrote:

Martin.au wrote:

Hithertoo wrote:

F/12 on the long end... No thanks.

F/12?

Do you want a lecture on equivalence? It's a 100-400mm, f4-6.3.

It's f/12 for people who like to frame a shot based on DoF, not actual exposure parameters like shutter speed.

... which is good, because DOF on a little bird 15 feet away at 400mm f6.4 is about an inch, which is just right.

Do you get a lot of 5-6" tall birds who happily stay within 15' of you where you live? Caged birds don't count. Around hare, it is more like 50'. The DoF then will be a more than adequate 8 inches. I'd much rather have f/4.

Maybe nzmacro can correct me if I'm wrong, but it seems to me that to get proper brightness of the underside of a flying bird, one would need to shoot at about ISO 2000 if one was at 1/1000 and f/6.3.