Back button focus on Canon 7D

<p>What is/are the advantages of using the back button focus on a Canon 7D or any other DSLR?</p>

<p>If you keep it press it locks the focus so you can keep on pressing the shutter thus avoiding focusing delays in between shots.</p>

<p>Once you get used to it you will NEVER go back. I never really liked the idea until I tried it seriously for a while a couple of years ago. My cameras now permanently stay on back button focus and AI servo. You miss far fewer action shots.</p>

<p>Take autofocus off the shutter release entirely, assign it to only the rear button, and you don't need to worry about focus shifts when you recompose, between bracketed shots, etc. For former users of manual focus cameras, it becomes sort of a "power-assisted" focus most useful in static situations like landscape photography, still life, etc. (This is from a Nikon user; Canon may differ a bit).</p>

<p>I'm a back button focus advocate as well. Work with it for a little while and you won't want to change.</p>

<p>Thanks for all the replies! Now,... how do you disable the half-down focus on the shutter on the Canon 7D?</p>

<p><a href="http://www.learn.usa.canon.com/resources/articles/2011/backbutton_af_article.shtml?categoryId=121">Back-button focus explained.</a></p>

<p>ME</p>

<p>On this topic, as a back button focust user on a 7D, how do I get the speedlight focus assist to operate when using back button AF? Using the AE lock as Focus doesn't operate the assist which really got me when trying to take snaps at a party.</p>