EOS 80D's setting for Initial AF Point, AI Servo AF

[haggie]

Now the weather is getting a bit better, I have been playing with my EOS 80D and my 100-400 a get a better for the settings for the 80D's AF system with subjects changing speed and direction like aircraft and birds.

I am making progress, but there is one variable I do not understand.
Or better: I do not see any difference between the settings.

In the C.Fn II -11 Initial AF Point, AI Servo AF there are two possible settings in addition to 0: Auto:
Initial AF pt selected and Manual AF pt.

I find the text in the EOS 80D's Manual lacking clarity. Or it may simply be too brief.
And when I try the 2 different settings, I do not see any difference in behavior.

Of course, I am probably not complete in my experiments, because there MUST be a difference.......
Can anybody help me: what is the difference between these 2 settings and when is it relevant?

 

[Sharlin]

Basically, the latter uses whatever AF point is selected in one-point mode as the initial point, whereas the former allows you to maintain the initial point selection separately from whatever you have selected in the one-point mode.

 

[haggie]

Thanks for your reply, Sharlin.

So, with the same selected AF-point in Single Point AF , when switched to AI Servo AF + Auto Selection 45-Point AF, initially both start with the same AF point.
But that the difference only occurs when, after doing this, the active AF Point in Single Point AF has been changed.

Then, with Initial AF pt selected the AF in AI Servo AF + Auto Selection 45-Point AF starts with the original AF-point, and with Manual AF pt the AF in AI Servo AF + Auto Selection 45-Point AF starts with the changed AF-point and keeps using any change to that selected AF-point after that.

Is this a correct understanding?

 

[YuengLinger]

Thanks for your reply, Sharlin.

So, with the same selected AF-point in Single Point AF , when switched to AI Servo AF + Auto Selection 45-Point AF, initially both start with the same AF point.
But that the difference only occurs when, after doing this, the active AF Point in Single Point AF has been changed.

Then, with Initial AF pt selected the AF in AI Servo AF + Auto Selection 45-Point AF starts with the original AF-point, and with Manual AF pt the AF in AI Servo AF + Auto Selection 45-Point AF starts with the changed AF-point and keeps using any change to that selected AF-point after that.

Is this a correct understanding?

When I choose Auto Selection, the camera is choosing where to start, which is usually whatever is closest with good contrast. So, for BiF, it does pick up the bird(s), but I kind of like a little more control, so...

With INITIAL AF point, when in AI Servo with Auto Selection, you can choose the "starting point." And you can change the starting point from shot to shot if you like. I think it works quite well.

MANUAL does not seem particularly useful, but perhaps I'm not understanding what scenario it is intended for.

See page 422 of the US English version of the User's Manual.

 

[Sharlin]

The difference is simply whether the selected AF point is stored separately for one-point and all-point modes, or if it's the same for both of them.