BBF on a D7100 and unable to lock & recompose

C

carguy

Senior Member
I recently (finally) switched to Back Button Focus (BBF) on my D7100 to shoot some auto racing, soccer & hockey. I really like the flow now that I've taken the plunge.

Recently shooting soccer, I've realized I cannot lock on a subject and recompose. The camera loses focus wile holding down the button and moving the camera slightly to re-frame the image.

Is this normal while using BBF or perhaps there is a setting I should adjust?

Thanks - Joe
 
Horoscope Fish

Horoscope Fish

Senior Member
carguy said:
I recently (finally) switched to Back Button Focus (BBF) on my D7100 to shoot some auto racing, soccer & hockey. I really like the flow now that I've taken the plunge.

Recently shooting soccer, I've realized I cannot lock on a subject and recompose. The camera loses focus wile holding down the button and moving the camera slightly to re-frame the image.

Is this normal while using BBF or perhaps there is a setting I should adjust?

Thanks - Joe
Click to expand...
Maybe I'm not understanding what's happening, or what you're trying to do exactly, but when using BBF releasing the back-button "locks" focus until you press it again. So to focus-and-recompose a shot you would press the back-button to achieve focus lock on your subject, release the back-button, recompose the shot and then fire the shutter.
 
C

carguy

Senior Member
Horoscope Fish said:
Maybe I'm not understanding what's happening, or what you're trying to do exactly, but when using BBF releasing the back-button "locks" focus until you press it again. So to focus-and-recompose a shot you would press the back-button to achieve focus lock on your subject, release the back-button, recompose the shot and then fire the shutter.
Click to expand...

Interesting. I was using it wrong apparently....

I was pressing and holding the button to shoot. Apparently I should press to lock focus on the subject and release - the camera will keep the focus locked until I press the button again?

So when shooting an active subject (sports), I should lock on the player, let go (using continuous focus) and shoot. Is this correct?
 
4

480sparky

Senior Member
carguy said:
Interesting. I was using it wrong apparently....

I was pressing and holding the button to shoot. Apparently I should press to lock focus on the subject and release - the camera will keep the focus locked until I press the button again?

So when shooting an active subject (sports), I should lock on the player, let go (using continuous focus) and shoot. Is this correct?
Click to expand...

Focus will be locked on the distance set when you release the BBF button. So if the subject is moving towards or away from you, it will move to a distance that will be out-of-focus.

This is why I don't use BBF for moving subjects.
 
C

carguy

Senior Member
480sparky said:
Focus will be locked on the distance set when you release the BBF button. So if the subject is moving towards or away from you, it will move to a distance that will be out-of-focus.

This is why I don't use BBF for moving subjects.
Click to expand...
Having this work in AF-C eliminates the issue you mention above. From what I'm reading, BBF only works correctly in AF-C mode, correct?
 
Horoscope Fish

Horoscope Fish

Senior Member
carguy said:
... Apparently I should press to lock focus on the subject and release - the camera will keep the focus locked until I press the button again?
Click to expand...
Well, it depends... Think of BBF as, AF-C "on demand": as long as you keep pressing the button, you're in AF-C. Release the button and everything stops. You can press-and-release if your subject is stationary but you would probably want to press and hold, for continuous focusing, if the subject is in motion.

carguy said:
So when shooting an active subject (sports), I should lock on the player, let go (using continuous focus) and shoot. Is this correct?
Click to expand...
It depends on how you want to frame the shot and whether the player is in motion or not...

If the subject is in constant motion, but I can keep one or more focus-points on the subject, I would keep the button pressed and fire the shot (a la AF-C).
If the subject is stationary and I wanted focus and recompose I would press the button to focus on the player, release the button, recompose and press the shutter button (a la AF-S).

The only thing I don't like about BBF is that it over-rides the Focus Lock Priority - Focus setting in the menus. Meaning the camera will take a shot even without having achieved focus-lock. That being the case I have to pay close attention to the focus-lock indicator-light in the viewfinder; or I guess I can ignore it and take my chances with out of focus shots. This is the primary reason I switch back and forth so frequently between BBF and Shutter-Button Focus. Sometimes I can deal with how BBF works, sometimes I can't. Fortunately, for me, I don't have any issue switching between the two.
 
C

carguy

Senior Member
Alright, so when I was attempting to recompose, it was when the goalie was standing there bored on his end of the field. I was pressing and holding the button, when I moved the camera it re-focused. I should have pressed/released the button and recomposed, just tested this out at home and that works.

When shooting a moving player, I should be pressing and holding the button while they are moving and while I shoot, correct?
 
D

Don Kuykendall_RIP

RIP :(
What I like about it is that if I see a bird sitting I can focus on him and let go. Then put the camera down by my side and it will still stay focused on that bird until I press the BBF button again. I do this while waiting on the bird to fly. That way when I see him start to move the camera is at the starting focus point.
 
Horoscope Fish

Horoscope Fish

Senior Member
carguy said:
When shooting a moving player, I should be pressing and holding the button while they are moving and while I shoot, correct?
Click to expand...
Generally speaking, yes.

When using AF-C your camera "assumes" whatever is under the active focus-point is your subject. Once it "understands" what your subject is AF-C works to keep focus on that subject, even as it moves around in the frame. It works pretty well but it's not fool-proof.
 
D

Don Kuykendall_RIP

RIP :(
Horoscope Fish said:
Generally speaking, yes.

When using AF-C your camera "assumes" whatever is under the active focus-point is your subject. Once it "understands" what your subject is AF-C works to keep focus on that subject, even as it moves around in the frame. It works pretty well but it's not fool-proof.
Click to expand...

From what I have figured out there is nothing in photography that is fool proof. WE just strive to do our best.
 
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