Back Button Focus 6D

[jpharbour]

Two Quick Questions: 

1.  I viewed a video that stated that when using BBF with AI Servo, only the center focus point is active.  So if you are tracking a bird in flght, and if the center point is not on the subject, you will lose focus.  Is that correct?

2.  Can you set C1 for a back button focus situation and C2 for shutter button focus?.  Again, I've seen videos that state that the center point focus for One Shot is more precise than AI Servo.  So with landscape (no chance of movement), I might want to use shutter button focus.  Any thoughts?

Thanks

[TTMartin]

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@jpharbour wrote:

Two Quick Questions: 

1.  I viewed a video that stated that when using BBF with AI Servo, only the center focus point is active.  So if you are tracking a bird in flght, and if the center point is not on the subject, you will lose focus.  Is that correct?

2.  Can you set C1 for a back button focus situation and C2 for shutter button focus?.  Again, I've seen videos that state that the center point focus for One Shot is more precise than AI Servo.  So with landscape (no chance of movement), I might want to use shutter button focus.  Any thoughts?

Thanks

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1 - It depends. If you are in AIServo and Automatic AF Point Selection mode and continue to hold down the back button the camera will hand off the subject to the outer AF points. The moment you release the back button you need to require the subject with the center AF point.

2- I don't use BBF. Instead I reprogram the AF ON button to be AF OFF. Most of the time I want continuous focus, there are only a few times when I want to suspend focus. To my it doesn't make sense to have to press two buttons (BBF and shutter) most of the time, so a few times I can suspend focus by releasing the BBF. By setting up the camera the way I do, when I press or half press the shutter button I get continuous focus. When don't want continuous focus like shooting a bird through branches, then I simply press the AF OFF button and is suspends continuous focus. That way I can focus and recompose, or manually focus through the branches. As a rule I've found the times I want to suspend focus I have the time to think about pressing two buttons, where when I want continuous focus I don't want to have to mess with two buttons, like in the photo below.

[diverhank]

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@jpharbour wrote:

Two Quick Questions: 

1.  I viewed a video that stated that when using BBF with AI Servo, only the center focus point is active.  So if you are tracking a bird in flght, and if the center point is not on the subject, you will lose focus.  Is that correct?

2.  Can you set C1 for a back button focus situation and C2 for shutter button focus?.  Again, I've seen videos that state that the center point focus for One Shot is more precise than AI Servo.  So with landscape (no chance of movement), I might want to use shutter button focus.  Any thoughts?

Thanks

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#1 is not so...BBF and shutter button focus works identically...just that the shutter button is no longer focusing with the BBF scheme.  For AI Servo, you must first establish (initial) focus.  Once focus is achieved, as long as you keep depressing the focus button, focus will be maintained using other focus points as the target moves off the center point.  The 6D does not have many outer points so it doesn't help as much as other cameras (like the 7DII).  If you fail to keep the camera following the target, focus will be lost if you ran out of focus points.

I don't think you can use the custom C's to do what you want.  Once you choose BBF, everything except the green square uses BBF.

[TTMartin]

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@diverhank wrote:

I don't think you can use the custom C's to do what you want.  Once you choose BBF, everything except the green square uses BBF.

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I'm pretty sure the Custom User Settings save the entire state of the camera including different Custom Function settings. 

[diverhank]

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@TTMartin wrote:

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@diverhank wrote:

I don't think you can use the custom C's to do what you want.  Once you choose BBF, everything except the green square uses BBF.

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I'm pretty sure the Custom User Settings save the entire state of the camera including different Custom Function settings. 

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I think you're right.

[RobertTheFat]

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@diverhank wrote:

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@TTMartin wrote:

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@diverhank wrote:

I don't think you can use the custom C's to do what you want.  Once you choose BBF, everything except the green square uses BBF.

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I'm pretty sure the Custom User Settings save the entire state of the camera including different Custom Function settings. 

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I think you're right.

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I think it may be more true on recent cameras than it was on some of the older models. The 6D has been around for a while, so I wouldn't count on it. OTOH, it's one of those cases where you don't even need to take a picture in order to test it.

[Waddizzle]

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@RobertTheFat wrote:

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@diverhank wrote:

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@TTMartin wrote:

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@diverhank wrote:

I don't think you can use the custom C's to do what you want.  Once you choose BBF, everything except the green square uses BBF.

---

I'm pretty sure the Custom User Settings save the entire state of the camera including different Custom Function settings. 

---

I think you're right.

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I think it may be more true on recent cameras than it was on some of the older models. The 6D has been around for a while, so I wouldn't count on it. OTOH, it's one of those cases where you don't even need to take a picture in order to test it.

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There is a table in the instruction manual that shows which settings are saved, and which are not.