gschlact wrote in post #18351558
I'll just chime in...., It is ultra rare that focus won't be achieved by the camera under the intended af point in servo mode. Whether or not that focus was locked where you intended is a different question. In other words, in Servo, there will be focus achieved and tracked or reacquired continuously so the beep would be continuous whether it was on your subject or not for 99% of the time. I hope this makes sense. Beeping would not indicate accuracy of focus point focus.
CyberCat wrote in post #18351613
I wish I could show you the many blurred images I got when shooting a greyhound coursing event on a very cloudy day. But I deleted them all.
AI Servo is not a miracle mode, there are many other elements of successful focusing.
mwsilver wrote in post #18351631
Exactly, but it is still a miracle how many keepers one can get in AIServo and Continuous High Speed.
Based upon my own experiences with AI Servo this past weekend, to shoot a youth lacrosse game with one grandson on the team, I am in full agreement with the comments made above. As I indicated earlier, out of close to 400 shots there was only ONE shot that was totally out of focus (and I was shooting at 320mm f/5.6, a 70-200 f/4 IS with 1.4x TC). So my own experience is closer to mwsilver's description than it is to CyberCat's. But OTOH, I would lift my finger off the back button, recenter on my new primary player of interest and press the back button to focus on him and hold it down while he ran thru the viewfinder and AI Servo tracked him as I shot....(repeat as necessary)
I can understand how 'focus achieved and tracked or reacquired continuously, so the beep would be continuous whether it was on your subject or not for 99% of the time', as gschlact put it; that could be extremely annoying. But given my description of my use of AI Servo in the previous paragraph, and given my reading past posts from folks complaining (although not necessarily in the context of 7DII, that I can recall), 'I could not release shutter because the camera had not achieved focus', some form of 'AF acquired' would be comforting. The [A]+ description sounds similar enough to what I would like to be able to try out. Admittedly, having a lot of moving lacrosse players is admittedly very different than aiming at a still subject (toddler) who suddenly moves, forcing the need for tracking. Yet even in lacrosse, quite often a player is in place for a moment before they dart off in some particular direction...the [A]+ behavior just might work well enough. I will try it out the next time we go to one of the lacrosse meets.
The analogy would be like a fighter pilot acquiring radar lock on the adversary, getting tone, and then releasing the missle and automatic tracking continues to follow the selected target to guide the missle to that mark (while the pilot acquires a new target). I can hope...after all, after the early frustrations with Auto ISO over a decade ago, eventually Canon did finally get it pretty close to 'well done'.
The disadvantages of [A]+ are numerous, among the most problematic is the lack of much customization such as BBF becomes default shutter button focus.