Do you remember if the body was off when you put on this lens? Was the VR off? It's possible that an electrical glitch occurred but unfortunately no...
Honestly none of the bodies should AF if trying to capture an empty sky. Not sure why the body won't fire. When in AF-C and BBF, bodies usually fire...
Yes, the front dial controls the aperture. The rear dial controls the shutter speed or ISO. It you put the D7100 in Aperture Priority with Auto ISO,...
Do you happen to know if this is a Cooper's Hawk? The streaking goes all the way down its chest. The thing is it doesn't look quite so tubular like a...