Canon 7D2 auto focus quesrion

[Stillh2o]

While in servo mode, under what setting can I use a single focus point to track a subject?

[diverhank]

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@Stillh2o wrote:

I appreciate your advise, however when using the single point in Servo, the points will expand and continue to track the subject.  I do use single point to aquire focus on a running back, quarterback and let the points expand using single point AF.  

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No it does not expand  with a single point. That's what I'm trying to tell you.  Since there is only one point to track with, you have to have that one point on the object as it moves if you want focus to maintain.  You need to choose one of the multiple point focusing scheme before it will expand to track for you - the real advantage of AI Servo.

Back to your original question. Here is how you activate and change focus point:

[Stillh2o]

Just to make sure I am understanding what you are saying, if I am in single point AF in Servo, the single point will not expand to 3 or 4 points together and track the subject I am foucused on?

[diverhank]

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@Stillh2o wrote:

Just to make sure I am understanding what you are saying, if I am in single point AF in Servo, the single point will not expand to 3 or 4 points together and track the subject I am foucused on?

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Correct.  It will longitudinally (moving away or towards you) but if it moves laterally it won't with a single AF point.  You need to choose a mode that has multiple points and it will auto select the point for you as the object moves laterally.  Usually the most effective is the center point with 8 assists.  I use it 95% of the time for BIF.

Here is a really good Canon guide for the 7DII...you should read it.

http://learn.usa.canon.com/resources/articles/2014/eos7dmk2_afGuidebook.shtml

[Stillh2o]

Okay, it is one of 2 things.  1. I did/am not using the corrects terminology, words or not explaining what I mean well enough or 2. you are incorrect.  I can use the single AF point and it will expand but you have to go into the menu and change a setting.  

[TTMartin]

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@Stillh2o wrote:

Just to make sure I am understanding what you are saying, if I am in single point AF in Servo, the single point will not expand to 3 or 4 points together and track the subject I am foucused on?

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What you want is to be in an auto AF point selection mode.

All Canon dSLRs behave differently when it comes to auto AF point selection mode and AIServo compared to One Shot focus mode.

When in an auto AF point selection mode and One Shot the camera will choose from all available AF points and choose the closest active AF point that has adequate contrast to achieve focus.

When in an auto AF point selection mode and AIServo, the camera starts with a single AF point and uses the other active AF points to continue to track the subject if they move away from the starting AF point.

For most Canon dSLR the starting point for tracking when in auto AF point selection mode and AIServo is the center AF point. Starting with the classic 7D more advanced cameras allow you to choose a different starting point for focus tracking when in auto AF point selection mode and AIServo. Just to confuse things the 7D Mk II also allows you to set it up, so it will automatically choose the starting AF point, much like other cameras do in auto AF point selection mode and One Shot. This however is not the default way the camera is set up, and you would need to reconfigure it to do that.

So what you actually want to use is either the 65 point auto AF point selection and AIServo, or one of the Zone auto AF point selection modes and AIServo. This will start with a single AF point, and if your subject moves off that AF point laterally the camera will hand off focus to one of the adjacent active AF points and continue tracking your subject. 

[Stillh2o]

Okay. I appreciate everyone's input. Like I stated earlier, I found where I needed to go to in the menu to accomplish what I was needing.

[TTMartin]

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@Stillh2o wrote:

Okay, it is one of 2 things.  1. I did/am not using the corrects terminology, words or not explaining what I mean well enough or 2. you are incorrect.  I can use the single AF point and it will expand but you have to go into the menu and change a setting.  

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You are referring to AF point expansion mode, which doesn't behave like you think it does. With AF point expansion mode (4 or 8 point) the center AF point will attempt to focus on the subject, if it fails to detect a subject only then will it use one of the surrounding AF points. It does not track and hand off to the adjacent AF points like when using auto AF point selection and AIServo. 

[Stillh2o]

Okay, like I have said before I have a single AF square. When it locks in on a subject, other focus points surrounding it will come up. It is a single point, not expanded.

[diverhank]

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@Stillh2o wrote:

Okay, it is one of 2 things.  1. I did/am not using the corrects terminology, words or not explaining what I mean well enough or 2. you are incorrect.  I can use the single AF point and it will expand but you have to go into the menu and change a setting.  

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Most likely you are using the wrong terminology. No matter, you figured out what you need.  Most likely you are looking at the square that is the initial AF point in one of the expanded focus group.  When you say "a single AF point", it's just one single point.  You use this mostly when you want precise focus on the eye.  

The link I provided will help you with the correct terminology.  It's possible that I'm wrong but I don't think so.  I'm done with this topic.  I'd like to help those who want help.  I don't think you're interested in it.

[Stillh2o]

Okay, thanks.