AF-On & Shutter release ?

So with the new camera, I'm going to make a real effort to learn how using the AF-On button for focusing. Why would there be a need to select Enable or Disable under a6/AF-On Only for the shutter release (based on focused/not-focused) if the shutter priority (focus or release) was already set under Autofocus a1/a2? Would the Enable/Disable selection take precedence over the priority selection if the settings were different? Thanks.

I'm not entirely sure if my response will address your concern because I'm not sure I fully understand your question. But ...

When I received my D500, the AF-On button was factory set for BBF. The shutter actuation button was also set up to focus as well as to take the pics. The problem is when using BBF, if you want to focus and recompose, you need to focus with the back button, remove your thumb from the back button, recompose, then take the pic with the shutter actuation button. However, if the shutter activation button is simultaneously set to focus, then when you go to take the pic, the camera will refocus before the the shutter fires.

Maybe if I rephrase/shorten. Camera has option to select Focus or Release for the shutter operation under AFC (a1 menu) and AFS (a2 menu) AND also an option to select Enable(shutter release any time) or Disable(shutter release only when focused) under AF-On only (a6). Does one menu location/change take priority over the other if the settings contradict each other?

Camera Fun said:

Maybe if I rephrase/shorten. Camera has option to select Focus or Release for the shutter operation under AFC (a1 menu) and AFS (a2 menu) AND also an option to select Enable(shutter release any time) or Disable(shutter release only when focused) under AF-On only (a6). Does one menu location/change take priority over the other if the settings contradict each other?

Click to expand...

The A6 menu option is regarding if the camera will actually take the photo if out of focus. A1/A2 will take away the auto-focus when you half-press the shutter release, so it will be auto-exposure metering only when you half-press. You would do that so the camera does not try to re-focus as you press the shutter release and override what you did with the back button focus.

My understanding from the Manual (not verified by actual operation) is this: when AF-ON only is selected, the shutter button will no longer function AF by half-pressing. So a1 and a2 are out. The only way then to decide shutter priority is to set enable or disable for shutter-release under AF-ON only.

hark said:

... The problem is when using BBF, if you want to focus and recompose, you need to focus with the back button, remove your thumb from the back button, recompose, then take the pic with the shutter actuation button. However, if the shutter activation button is simultaneously set to focus, then when you go to take the pic, the camera will refocus before the the shutter fires.

Click to expand...

I'm a bit confused about this recompose thing: I have no problem with the process of using BBF. What if I only use shutter button to AF and then how do I recompose? Hold shutter button halfway?

blackstar said:

I'm a bit confused about this recompose thing: I have no problem with the process of using BBF. What if I only use shutter button to AF and then how do I recompose? Hold shutter button halfway?

Click to expand...

When using BBF, the nice thing is the ability to focus and the ability to take the pic are now separated into 2 different actions. But if you are only using your shutter button for focusing, then it depends on how the camera is set. For static subjects, usually the camera is set for AF-S. And if so, then you focus with a 1/2 press, keep the shutter half-pressed, and recompose. But if you are using the shutter button for focusing and your camera is set to AF-C, then you are out of luck. That's because you no longer have the ability to focus and recompose with the shutter button.

hark said:

... But if you are using the shutter button for focusing and your camera is set to AF-C, then you are out of luck. That's because you no longer have the ability to focus and recompose with the shutter button.

Click to expand...

So if I set AF-C and use shutter button, I can't recompose. Then what if I set AF-C and use BBF, can I still recompose by releasing BBF?

May want to read this article about BBF and mirrorless.

"So, what changed? Simple – AF points are now all over the viewfinder. The need to focus and recompose is mostly gone (depending on how you shoot)."

https://backcountrygallery.com/has-mirrorless-killed-back-button-af/

blackstar said:

So if I set AF-C and use shutter button, I can't recompose. Then what if I set AF-C and use BBF, can I still recompose by releasing BBF?

Click to expand...

The article Needa quoted looks very informative. Steve Perry is quite knowledgeable about Nikon gear so I'd trust what he says. Although I don't have Mirrorless and still use a DSLR, what you are asking is correct for a DSLR. But how quickly you can change focus points on a mirrorless camera is something I cannot answer since I don't own one.

You can recompose using BBF in AF-C by releasing the button. If you continue to press the button, it keeps focusing. At least the D500 functions that way.

I don't know. It seems like it is easier to just recompose rather than change focus points. Sometimes I use an off-center focus point if I am shooting at birds because their eye is rarely in the center of the frame.

I believe (haven't tried it yet) you need a new Z for wild animal shooting, especially birds cause it can automatically track down bird's eyes in the frame for you, so you don't need to recompose or change focus point anymore. Just click down the shutter button when you see bird's eye(s) in the focus square.

Steve Perry also has a video on BBF. It is very helpful. He is a pro wildlife photographer that has written a book on the AF System for the Z cameras. He is a good resource. I have found his material helpful.