My photo club is attending a raptor event called Hawkwatch. It is a wonderful event and I have attended it twice and shot with my Canon 7D2 and several different telephoto lenses. I did this shot with the 7D2 and 100-400mm f/4.5-5.6L IS ii lens.
Nice thing about this event is that you can get up close to the raptors to get good imagery.
This time, I will be shooting with my Sony gear: A6400 with the new APSC 70-350mm f/4.5-6.3 G OSS lens and my A7iii with the 70-200mm f/4 G OSS lens. The latter combination might be useful when shooting raptors up close.
I am really anxious to see just how well the 70-350mm Sony lens does on my A6400 with the Sony real-time tracking capability... That combination is less than half the weight of the Canon 7D2 and 100-400mm Mark-ii lens. It is 50mm shorter at the longest end but, 30mm wider at the shortest focal length. I lose about a half stop at maximum extension but the savings in weight will, I think, make up for the above short comings. The lens can only be used on an APSC camera or a full-frame camera in APSC mode. That will be no problem for me since I always used the 100-400mm Mark-2 Canon on my crop sensor 7D Mark-2...