(F/5, 100mm, 1/100 sec, ISO 200, Canon 5D Mk II)
These are the "back buttons" on my camera. I use the Focus Point Selection button all the time, yet I have never utilized the AE-Lock (*) or the AF-ON buttons. This past Saturday I configured my camera so I could use these and what a difference. I will probably rarely use the AE-Lock button, but the back button auto-focus is my new favorite feature on my camera.