Despite the presence of the labels, the Sony A7's user interface is exceptionally configurable. The C1 button on the top panel and the C2 button at the top of the rear panel are of course both configurable, as is the C3 button, which doubles as the Trash button in playback mode. All three of these buttons can have any of 46 functions assigned to them, or they can be left unassigned. Additionally, the center button of the rear controller can have any of 47 functions assigned, and the left, right, and down keys can each have any of 39 assigned to them. This surely sets a new benchmark for camera configurability. (There may have been a camera or cameras with more configuration options, I just can't recall any.)