Back Button Focus on Nikons per Ray Soares??

Hi All. I have been working on setting up my D7000 per the suggestions of Ray Soares. I very much appreciate his time in writing these down for us. I am wondering about the part where he says to link the AE-L button to AF-ON. I think that Canon calls this Back Button Focus and maybe Nikon does also. I am not questioning Ray AT ALL, but I am wondering what the advantage of setting it up this way is. Now I have lost AE-L. Again, I simply do not know and just would like to hear more about setting up the camera this way.

Thanks for any input!!

Ron

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'The question is not what you look at, but what you see'. Henry David Thoreau
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