Absolutely, Rab. As the bird flies by, get a spot measurement and then set aperture, shutter speed and ISO. Then you’re ready to shoot him. Oops.
Hahaha. Making fun of poor rabanito…
Actually what I mean is not exactly like how you describe it
Even if I’m preparing to do landscapes or anything static, if I know that maybe I’m going to meet flying birds I prepare for that. Something like “f/11 and be there” 😊
So when the bird takes off or passes by, I am ready.
Landscapes and flowers allow for lots more time to change settings than all the way around.
The problem is usually with well illuminated white birds. Grey herons are not but egrets or swans could be partly overexposed in a way where there is no detail in the highligts and no PP is going to bring it back.
So if I expect to meet or am approaching them, I try to be ready. If taking a spot measurement is not possible (they are maybe far away or still invisible), I meter my hand and add one or two stops so that that white will fall where there is still detail. If the illumination is the same, the white bird will fall more or less in zone VI/VII. Of course this is a rule of thumb but it usually works.
For shooting flying birds I need a fast shutter speed and a good autofocus and some “f/11 and be there”. And a tracking ability I do not posess
This means probably a (much) higher ISO than that which I use for static subjects.
So, if I suddenly meet a wonderful landscape, I’d need, say, some 30 seconds to change to a lower ISO and put the camera from Manual to Automatic Mode (I use aperture) Landscapes don’t fly away.
Conversely, if a bird takes off, I’m ready. In these 30 seconds the bird can be far away. Not the right time to make changes, as you rightly point out 😊
Not that I am very successful, don’t take me wrong. But that’s the theory.