The circle represents the 8° field of view typical of 8x45 binoculars (my instrument of choice for viewing the Milky Way).
Morning is my favorite time for serious observing. When you first wake up your eyes are as dark-adapted as they can be. Turn on a bathroom light and it takes over an hour for the rhodopsin in your retinae to regenerate fully!
(Rhodopsin is the photo-sensitive chemical that allows your rods to sense light. Night vision has nothing to do with how fast your pupils dilate; they dilate almost immediately in the dark!)
So, I walk around in the morning with a red light. Only after I've completed my naked-eye and telescopic observing will I turn on the camera to take a snapshot (the camera's display really screws up my rhodopsin!). I'm weird like that.
I tell you this to emphasize the importance of dark adaptation if you want to fully appreciate the glory of the Milky Way.

Canon EOS M100
85mm*f1.8
5s@ISO4000
*136mm with crop factor

B&W conversion and added stuff.