Birds - Detail - Distance - Focal Length
I am somewhat stating the obvious, but hoping for some quick rules of thumb you experienced birders use. Specifically, looking for distance ranges at 400mm w/ 7dii that still give you acceptable detail resolution on your birding. (I do realize that longer FL is a birders best friend) so three main questions below....
It's all about "pixels on the duck. "
(1) How many pixels per inch of "duck" do you minimally try to keep?
(I know when shooting Sports, I am not happy with 100% view detail if less than 100 pixels per inch on someone's face.)
(2) I am not sure that 100 ppi of feathers is enough detail at 100%?
7dii +400mm in the narrower sensor direction gives:
. . @26ft 12 inches of 'duck' or 300 ppi from the ~3600 pixels
It linearly grows so @52ft gives 200ppi and @78ft gives 100 ppi
(3) So, how do you get so close? If among 50ft trees and bird flying at treetop, if the bird is 50ft away, you are at ~78' limit and down to 100 ppi.
I shot a 10 point buck yesterday that was further than I realized at ~400 ft that gave me a soft 25 ppi result I wasn't happy with. (likely some atmospherics added to softness). I was pretty excited to see it, didn't realize just how far it was until I got home to the softness.
) 