This 翠鳥 is living in the HK Park and many C Hings wait for her every day.
I used 384 + 1.4x or 2x that is about 10 feets from her and not to mention if shooting in Yuen Long that the birds are far far away! The pros use 684 + DX body + 17EII or now the 20EIII that is >1500mm on 35mm format!
Heard frow web rumour Nikon may have micro 4/3 body, if this is true then 384 + 1.4 or 2x + micro 4/3 body (VR on body??) equivalent to 840 or 1200mm on 35mm format is good enough for bird shooting in Yuen Long!