I have always been confused by the af/ae lock button. If someone can explain the nuances, it would be greatly appreciated. My question is: Why would one press the af/ae lock button when the shutter button could do the same thing on a focus, recompose. I understand why one would set the button to lock ae only, but I just can't seem to grasp why it would ever be used to lock ae/af or just af. Is the purpose for the ae/af for something other than focus/recompose? Thanks in advance for your advice.