The Acratech Ultimate ballhead is the best head I've found for my macro photography.  With a typical ballhead you have a large metal housing around the ball, and it has a u-slot opening in the front of the housing that allows you to move the camera downward into the u-slot when you want to shoot toward subjects on the ground, so it has limitation for framing your subject.  With the Acratech head, they have cut away the front 45 degrees of the housing which allows the user to maneuver the camera into unlimited positions for framing your subject.  So much easier for the macro photographers to get the camera in all the different angles it takes to frame up a subject.

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