Back Button Focus Issue

[paigew]

Is there a separate control to deactivate focus on the shutter button? .

Yes, it's in the custom focus settings. In your menu.

Sent from my Pixel 3 using Tapatalk

 

[PJM]

I have characterized the "odd" behavior of my camera further and it seems quite consistent. Again, the AE-L/AF-L button is set to AF ON and the the focus mode is set to continuous, AF-C. There are two scenarios.

#1
Press and HOLD the back button. The camera will acquire focus on the target.
Fire the shutter.
Move to a new target. The camera will acquire focus on the new target.
This seems to work as expected.

#2
Press and RELEASE the back button. The camera will acquire focus on the target.
Fire the shutter.
Move to a new target.
Press the back button. Nothing happens. The camera does not acquire focus on the new target.
Press the shutter button half way and release.
Press the back button. The camera now acquires focus on the new target.

I noted Nikon has a firmware update for their 200-500mm telephoto lens that fixes an issue that sounds a lot like this but I saw nothing for the camera itself. This behavior is the same no matter what lens I attach.

 

[stevet1]

Another advantage I have found for using the AF-On button to back button focus doesn't have to do with focusing per se, but using it for AE lock and hold.
I was reading up on creating silhouettes.
I can expose for a white wall and lock that exposure, but that lock is only good for about six seconds or so.
By assigning the AF-On button to back button focus, I can expose for the white wall, press the lock button, hold down the AF-On button, swing my camera to the closer dark subject, and the camera autofocuses on it and holds the exposure lock for as long as I want as I recompose the shot.

Steve Thomas

 

[greybeard]

Disagree all you want, folks, but why use BFF when in continuous AF? Now I have to work two buttons while I shoot sequences, which I find quite clumsy. I'm already holding the shutter button, let it trigger the continuous AF.

BFF lets you separate the AF function from the shutter press, but I don't want it separate when I'm shooting continuous sequences of frames with continuous AF. That simply makes no sense.

BBF combines AF/S and AF/C into one operation. Holding your thumb down while shooting gives you AF/C. Taking your thumb off when you achieve focus on a selected point, gives you AF/S. If you have need of this then BBF is for you.

 

[DarkShadow]

Another advantage of BBF if you do any night photography long exposures etc.sometime it can be difficult to acquire auto focus in very low light but once acquired focus by using BBF set and forget, that to me is much easer than pushing the manual switch at the lens that could Inadvertently knock the focus out or pushing a switch at the camera body to keep the shutter button from trying to refocus over and over. I find BBF works like a charm in any shooting situation and IMO one of the greatest features of a camera. To each there own, there is no wrong or right way, you shoot what way works best for your shooting style.

 

[DarkShadow]

I have characterized the "odd" behavior of my camera further and it seems quite consistent. Again, the AE-L/AF-L button is set to AF ON and the the focus mode is set to continuous, AF-C. There are two scenarios.

#1
Press and HOLD the back button. The camera will acquire focus on the target.
Fire the shutter.
Move to a new target. The camera will acquire focus on the new target.
This seems to work as expected.

#2
Press and RELEASE the back button. The camera will acquire focus on the target.
Fire the shutter.
Move to a new target.
Press the back button. Nothing happens. The camera does not acquire focus on the new target.
Press the shutter button half way and release.
Press the back button. The camera now acquires focus on the new target.

I noted Nikon has a firmware update for their 200-500mm telephoto lens that fixes an issue that sounds a lot like this but I saw nothing for the camera itself. This behavior is the same no matter what lens I attach.

#2 That is strange, i had a similar situation like this before so i switched back to the shutter with similar results come to find it was with the lens Sigma 150-600mm Contemporary.Sometimes I had to give the manual AF override a turn to get the lens to focus again.This was a new replacement lens for the first one I got where the OS didn't work at all. So much for quality control.

 

[PJM]

#2 That is strange, i had a similar situation like this before so i switched back to the shutter with similar results come to find it was with the lens Sigma 150-600mm Contemporary.Sometimes I had to give the manual AF override a turn to get the lens to focus again.This was a new replacement lens for the first one I got where the OS didn't work at all. So much for quality control.

I'll give that a try and turning manual AF override off and see if it changes anything.
Thanks for the reply.

 

[DarkShadow]

Hope it works out for you.

 

[wfooshee]

Disagree all you want, folks, but why use BFF when in continuous AF? Now I have to work two buttons while I shoot sequences, which I find quite clumsy. I'm already holding the shutter button, let it trigger the continuous AF.

BFF lets you separate the AF function from the shutter press, but I don't want it separate when I'm shooting continuous sequences of frames with continuous AF. That simply makes no sense.

BBF combines AF/S and AF/C into one operation. Holding your thumb down while shooting gives you AF/C. Taking your thumb off when you achieve focus on a selected point, gives you AF/S. If you have need of this then BBF is for you.

I understand that perfectly. As I've stated, I almost never shoot AF/S, so working two buttons is just clumsy and unnecessary.