The rear AF button, as configured by default, accomplishes two things (when not using continuous focus). It achieves focus and locks it-- thus the AF-L label on the button. Obviously Continuous Focus works differently, but I essentially never use CF. That is an important consideration for this whole discussion as well as my conclusion. Use of CF is a strong supporting element for using BBF.

And yes...all Nikon lenses can be manually focused when in auto. The point here is that when configured for BBF, the lens does not attempt to refocus if the shutter button is released and pressed again.

I tried bbf a long time ago and aparently did not fully understand the process... Enter Steve Perry... Watched a video of his and said maybe i should try again... I followed his advice and never turned back... He made it very clear how it works especially for wild life photography...
Thanks Steve

The rear AF button, as configured by default, accomplishes two things (when not using continuous focus). It achieves focus and locks it-- thus the AF-L label on the button. Obviously Continuous Focus works differently, but I essentially never use CF. That is an important consideration for this whole discussion as well as my conclusion. Use of CF is a strong supporting element for using BBF.

And yes...all Nikon lenses can be manually focused when in auto. The point here is that when configured for BBF, the lens does not attempt to refocus if the shutter button is released and pressed again.

On April 3rd, I wrote that I was committing to a two-week trial of back button focus after discovering that my most recent cameras provide an easy, direct, one-click menu function to enable BBF or restore the factory default focus setup. Since I know that much of my shooting favors half-press shooting, this discovery eliminated one of my significant objections to changing...the awkwardness of going back and forth. That two weeks is now complete, and I am returning with a report of the results of my trial.

First, and most noteworthy, is that the world did not end as a result of half-press focusing being disabled on my camera. I successfully completed all of the shots that I attempted, and there were no meltdowns along the way. And nothing got broken or destroyed.

First and perhaps most important...I did discover one huge benefit of BBF that I had not considered...one which I do not recall ever reading about in any of the discussions which I have read. When set up for BBF, my cameras (Nikons) present a completely seamless combination of manual focus and automatic focus. As long as I do not press the focus button (I used AF-On, based on my 16 year familiarity with it), I can manually focus my camera. No switch to turn, No button to press, no Command Dial to spin. The camera is in manual focus. All of the lenses I was using were newer models with internal focus motors, and I realize that the functionality would be different or perhaps unavailable with older lenses, but it works perfectly with all lenses with motors. This is a pretty major plus, and I'm surprised we don't read about it more.

Second...I did not feel that there was a major benefit to be realized from the ability to press and release the AF button versus what I have been doing for years...pressing the button to focus and simply holding it while recomposing or living through whatever other delay in shooting might arise. For me, pressing and holding the button provides a mental reminder that the system is focused and ready to release when appropriate. I do not find it at all uncomfortable or inconvenient to simply hold the button to lock focus and prevent refocusing when pressing the shutter release.

Third...I do not find it at all inconvenient to access item a8 on the Custom Settings Menu and turn AF Activation (shutter release focus) on or off. a8 is at the bottom of the first page of the menu and simple to change.

So in summary...I plan to turn AF Activation back on and use half press focus as my default focus mode. But I'm really glad to realize the ability to integrate manual and automatic focus by using what we call BBF. That's a really good and useful thing. And I'm really glad to know that it is so easy to move between the two setups.

I switched to BBF some 20 years ago and never looked back.

It depends upon what you shoot and how you shoot it, whether BBF will be useful or not.

I shoot a lot of sports and some wildlife... a lot of active subjects. To be ready for anything I like to keep my cameras in continuous focus mode, which is best done with BBF (without BBF you can get in trouble occasionally, such as when using a focus and recompose technique).

The benefit to me is that I can use continuous focus equally well for both stationary and active subjects. No need to change focus modes.

I have full control over AF with my thumb.... it's not tied to shutter release, as it is when part of the half press.

Another benefit is that many modern zoom lenses are varifocal.... those don't maintain focus when zoomed. This is done to reduce complexity and keep the lenses affordable. But it means that the lens needs to be refocused any time the focal lens is changed. Having a camera in continuous focus mode (made possible with BBF) performs this refocusing instantly and automatically. If not in continuous focus mode, you have to remember to do the refocus yourself after each and every change of focal length.

Of course, someone who shoots posed portraits, architecture, scenics, still life and some other types of photos may have little to no need for BBF.