The fact is, you did not know a basic aspect of the 6D's autofocus, thus you misused it...and based on that, you found FALSELY that it was somehow the camera's fault that you did not get all the shots in focus in your little test. When in reality, it was your own lack of knowledge that very likely caused most of the problem. You assumed the 6D's autofocus worked like the 5D3's or 1DX's, regarding selecting a single point in servo mode, and assuming the point would transition to other points. Since there was no transition, once the target moved off your selected AF point, there was nothing for the system to focus on...and thus your subject moved out of the plane of focus. The focus certainly did lose lock, but it was your fault that it did.
All this really proves, is that most of the time, regarding the 6D's supposed lack of AF ability, or lack of making itself seem "impressive", it's really a lack of an impressive photographer using the camera.
When did I assume that? From what I can tell, I'm not the one making ass-umptions here. For someone who 'didn't make a false statement' you just made another one. Or if you prefer, an incorrect assumption based on ignorance of the facts.
Re-read what I stated...and what you stated...
When I tried servo tracking with an outer point on the 6D, it would frequently start out in focus then drift successively to backfocusing as the kid ran closer. The 1D X and 5DIII had no problem in that scenario. That may be technique, though - I suspect if I'd used just the center point, the 6D would have fared better. But that would mean cropping away a lot of the final images, since for composition purposes I prefer to leave the subject 'room to run' within the frame. With the center point on the 6D, the handoff to the outer points sometimes 'missed' and the outer point would lock onto a pipe on the wall or something - the high density of the 5DIII/1D X AF sensor makes those handoffs seamless.
“When I tried starting the servo tracking with an outer point on the 6D, it would frequently start out in focus then drift successively to backfocusing as the kid ran closer.”
Well, I can see why you had a problem here, because the 6D is not designed to specify a single point, then transition to other points in servo mode. You have to leave it on that one point, and keep the subject on it as you pan. You have to leave all points active, in order to track subjects that move across the frame, as you did in that situation. This is also how the 5D2’s AF worked, is it not?
The 5D3 and 1DX are the only bodies where you could do the action you are describing. There is no “handoff” from point to point here, that the 6D can do. You can only select single points at a time, or else leave them all active. You should have just left them all active for this situation…which I will admit will still leave you with a lower hit rate than the 5D3 or 1DX. The reason being, the top and especially the bottom points, absolutely love to grab foreground details on the ground and focus on them, rather than on the subject in the center vertical third of the frame. If there was a way to select all but the top and bottom points, then the AF system of the 6D would be even closer to the performance of the higher density, higher AF-point sensor…in servo mode...in my opinion. So that is definitely a case where Canon have "hobbled" the AF, and they should not have.
Did I include enough context for you? I stated, "When I tried servo tracking with an outer point on the 6D, it would frequently start out in focus then drift successively to backfocusing as the kid ran closer," and subsequently, "With the center point on the 6D, the handoff to the outer points sometimes 'missed' and the outer point would lock onto a pipe on the wall or something."
You added a couple of extra words to my statement, "When I tried starting the servo tracking with an outer point on the 6D, it would frequently start out in focus then drift successively to backfocusing as the kid ran closer.
” The point I was making was that servo tracking with a 6D outer point could not keep up with a kid running towards me, even with a fast-focusing lens like the 70-200 II.
I then went on to state that, "With the center point on the 6D, the handoff to the outer points sometimes 'missed'," and in that case, I was in automatic AF point selection mode, where the 6D should hand off the focus from the center point to the outer points...and again, it often failed to do so.
So, you apparently put my statement about poor tracking with an outer point and my seperate statement about poor handing off from the center point to the outer points together, and came to the conclusion that I was expecting servo tracking from an outer point to hand off to a center point. Of course, I could also have been in 11-pt auto select, started with the center point over my subject, then recomposed so an outer point was over the subject...and in that case, the focus should have been handed off from the outer point (back to) the center point with continuous if the subject moved through the frame. That was a technique I used with my 5DII...it even worked - about a third of the time.
So to summarize, I was using the 6D's AF system within it's design parameters, and using it correctly. It just wasn't holding up it's end of the bargain. But because I stated that it was failing to track a moving kid, you assumed (and have regurgitated several times) that I was trying to use it incorrectly due to ignorance of it's proper function, instead of accepting that the 6D just couldn't track the kid
. Staunch defense in the face of facts. Nice. I'd accuse you of being a FLAO (fanboi with loss of all objectivity), except you did basically call two of the 6D's AF points crap (apologies, to be precise you stated, "...the top and especially the bottom points, absolutely love to grab foreground details on the ground and focus on them, rather than on the subject in the center vertical third of the frame.").
I didn't make a false statement, again you are quoting me out of context. You never mentioned that you had tried the 6D yourself (or at least I did not see where you did...before I made the above observation. If you had said so in your preceding post, then my statement would have been false.)
Ignorance of the facts at the time you make a statement does not make your statement true. If you stated that I had blue eyes, that would be false too, regardless of whether or not I had previously stated my eye color. You made an assumption (several, actually) and you were wrong, but you won't admit it. But you go right ahead and crusade for the 6D...after all, it's a forum where you can express your opinion....even if that opinion is based on ignorance of certain facts and false assumptions about other facts.
Better yet, let's see some of those small birds and running kids tracked with your 6D...grab your 6D and go take some pictures, and show us those!