keithreeder wrote:
I understand your point Jim, but by any definition, older babies and toddlers are not static objects, and One Shot is simply not likely to be an appropriate AF choice for such subjects.
To follow your own logic, and trying to eliminate potential problems, suggesting an AF mode specifically not intended for moving (twitching, fidgeting, wriggling, squirming) obects instead of recommending a mode that is, strikes me as being a backward step.
Manually selected single Point AF and AI Servo is the way to go here.
You are missing the point here entirely. The OP can not get sharp people EVEN WHEN THEY ARE MOTIONLESS...note the posted image. If the OP can not isolate and fix the problems in technique with stationary people, then moving ones are out of the question. While not articulated this way in the first post, the OP is doing something different - likely unconsciously - when trying to shoot people that is not done for still life shots that end up sharp. Could be as trivial as a bad stance, talking to the kids while clicking shutter, nerves about muffing the shot, etc. In any case, keeping it simple helps narrow down the problems.
Jim
P.S. I manual focus on toddlers and kids all the time. In fact, photographers did it for decades prior to the invention of AF. Nothing against AF or its use and no value judgment on using it or not. But I can not envision a justification for using AI Focus or AI Servo on two stationary kids in good light [if the OP had even done that...never got a response.] IF the OP had one of those modes engaged, it is very easy for AF to hunt and pick a bad target, epsecially using slow lenses.
paulhodson, I think you're on to something. OP should definitely use single-point AF and make sure that point is on an area of high contrast.
I think you may be getting an inaccurate read from the AF-point software you're using, though (what is it, ZoomBrowser?). Note the crop is not from the center of the frame, and the original appears to have been shot in lanscape orientation.
The point though (as you said) probably still stands