release priority type for Back Button focusing in AF-C mode on Nikon D7100 body question

[Skip]

new to the forum. Greetings. I have my Nikon D7100 set to Back Button focusing with my AE-L/AF-L button reconfigured to AF- On with release priority for a1 (AF-C mode) and focus priority for a2 (AF-S) and realize that I have to be in AF-C for Back Button focusing (BBF). I am confused, however, with Steve's comment in his Secrets to Stunning Wildlife Photography ebook that one has to have it in release priority with BBF as he states "if you have it in focus priority you won't be able use this method in a focus and recompose situation." In his video on BBF he shows his D800 set up with BOTH release and focus icons showing up when he has his AF-L button reconfigured for BBF. With my D7100 I have only two choices for the reconfiguring, release or focus priority. Over the years my shots with BBF seem to be focused with a1 set for focus priority, but his ebook as above says it needs to be in release priority for BBF and AF-C mode. What should I have it set at, release or focus for BBF, and if release priority, don't I run the risk of having soft or out of focus shots when I use the BBF method? Thanks. Skip

 

[DRwyoming]

I am confused, however, with Steve's comment in his Secrets to Stunning Wildlife Photography ebook that one has to have it in release priority with BBF as he states "if you have it in focus priority you won't be able use this method in a focus and recompose situation."

You really do want to set the camera for Release Priority when doing focus-recompose shooting in AF-C mode when enabled by setting up BBAF.

In some images you can get away with leaving the camera in Focus Priority mode but that's just lucky when it happens. Think of a situation where you reframe the image so the selected focus point is on your subject's eye and then you use BBAF to establish focus on the eye followed by releasing the AF-ON button and recomposing.

If it just happens that whatever part of the image (perch, bird's breast, other part of the animal, etc.) is in focus and under the selected AF point after recomposing and the camera is set to Focus Priorty shutter release then sure the shutter will still fire and you'll capture the image. So in that happy case everything still works.

But if after recomposing the shot the selected AF point happens to fall on something like an area of out of focus background and the camera is set to Focus Priority shutter release then the shutter will not release as that area is well out of focus.

So for general use of BBAF focus-recompose shooting you really want to set the AF-C shutter release set to Release Priority and not Focus Priority. And when running BBAF you'll always operate the camera in AF-C mode as there's no reason to run AF-S mode since you can achieve the same focus-recompose results via selective use of the back panel AF-ON button so single servo really offers no benefits when shooting with BBAF.

Realistically even when not using BBAF I'd always set AF-C mode up for Release Priority which happens to be Nikon's default for continuous servo mode as you'd generally use AF-C for action sequences where focus won't always be dead on but you still generally want to capture images as often the focus is close enough to make the shot useable during fast action sequences like birds in flight or running animals.

Bottom line, it's best to set the AF-C release mode to Release Priority and not Focus Priority when setting up your camera for BBAF.

 

[Steve]

I was going to respond, but Dave perfectly hit every point I was going to make and then some

 

[Skip]

thank you for your responses. I was just confused as to Steve's video

at 7:56 photo of his BBF set up with the D800 and the menu showing both the icons together for release priority and focus priority as he set up AF-On with the AF-C mode in a1. And I just didn't know how much loss of sharp photos ( not in full focus) that I might experience using BBF with AF-C mode in release priority.

 

[Steve]

thank you for your responses. I was just confused as to Steve's video

at 7:56 photo of his BBF set up with the D800 and the menu showing both the icons together for release priority and focus priority as he set up AF-On with the AF-C mode in a1. And I just didn't know how much loss of sharp photos ( not in full focus) that I might experience using BBF with AF-C mode in release priority.

That video is incredibly old and was done when I was less than careful with what my menu settings showed. I think at the time I was experimenting with Release + Focus mode on that camera (or I was using it for a screen shot somewhere) and neglected to chance it back. That's the problem with constantly doing educational stuff - my settings are always changing and sometimes I forget to set them back LOL!!

 

[Skip]

thanks for your reply, Steve and Dave. I enjoy following the forums here and elsewhere. Quick responses are appreciated and helpful.

 

[east54]

Hi folks...understand to set release for AFC focus mode, what about the AF Area Mode setting? Single point or a dynamic such as 9 point for more accurate focus tracking with the back button depressed?

 

[Steve]

Hi folks...understand to set release for AFC focus mode, what about the AF Area Mode setting? Single point or a dynamic such as 9 point for more accurate focus tracking with the back button depressed?

One isn't really dependent on the other - BBAF and shutter release AF give the same performance in any AF mode. The AF area is chosen more based on the scene at hand than how you focus.

In general, I recommend using the smallest AF area you can successfully keep on the subject. If you can keep single point on target, that's the best bet. If not, then Group or one of the dynamic modes come into play.

 

[east54]

Thanks Steve.