AI SEVRO VS AI FOCUS

[iND]

Given the following situations would you use AI SERVO or AI FOCUS or NEITHER


Also for each would you use single point or multiple point focus


Camera is 50D or 5D lense is 70-200


Moving object


Quarterback taking the ball and about to move


Bride walking down the aisle


Portrait


Runner on second going to third base (you are on the third base side)

[neuroanatomist]

Generally, One Shot or AI-Focus when I want confirmation that AF has been achieved, AI-Servo when I know there will be movement.


Also, I always use single point AF (sometimes with sub-options available on the 7D, e.g. spot AF or expanded-point AF). I want to choose the active focus point, not let the camera do it for me (because more often than not, it will choose incorrectly).


Moving object - AI-Servo


Quarterback taking the ball and about to move - AI-Servo


Bride walking down the aisle - One Shot (timed to capture facial expressions), or AI-Focus


Portrait -One Shot


Runner on second going to third base (you are on the third base side) - AI-Servo

[iND]

Do you use AI SERVO to confirm that you get a second or third shot in focus


Or do you use it to ensure the first shot is in focus because of the lag time between the half shutter press AF and the actual shot


Or both

[neuroanatomist]

I presume you mean for the situations where I'd use One Shot (bride, portrait)? No, I wouldn't switch to AI-Servo. For portraits, people are holding still - unless you're very close to someone and using an f/1.2 lens, fractional movement is not going to throw off focus (but might cause motion blur, and AI-Servo does nothing for that since the mirror is up). For your example of a bride walking down the aisle, well, the whole point of a procession is that it's a stately walk timed to slow, classical music. She won't be moving fast enough warrant AI-Servo, IMO, but perhaps one of the wedding photographers here will chime in.