fotogk wrote:
I have been shooting for years and I am use to single, point back button focus, but have just started bird images. Purchase a Sigma 150-600 getting used to it. To be able to get tack sharp images which are the prefered setting for focus and focus tracking. Any additional birding resources would be appreciated.
Photzy.com has a library of 250 free e-books (really pamplets) and several are about birds. Attached is a pdf of one.
Other sites also have free tutorials, some as "books" or articles others video. Google "Bird Photography" or "Birds in Flight".