Al Focus vs Al Servo

New to the group, Hello everybody. I own a Canon 40D and I am wondering what is the difference between Al Servo and Al Focus. One of my favorite subject to shoot is birds and I am wondering if anyone of these setting will help me in my picture taking. thanks

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Reading those, at the lower left, should answer your questions.

One is mainly for moving objects, ok, so sport is mainly a moving object, but it is unpredictable, this is why we choose AI Servo

Check page 77 in the manual for a detailed answer. AI Focus is more or less the "auto" mode for focusing type. It will engage AI-Servo if it detects movement in the subject, but otherwise stays with One-Shot.

AI Focus is for people who enjoy frustration.

AI Focus is a combination of One-Shot and AI Servo. Unfortunatley it combines the bad points of each.

AI focus is where the camera tries to guess whether One shot or AI Servo is the best focusing type. Unfortunately, cameras are never as good as humans for deciding this and have a tendancy to get things wrong (addition to Murphy's law - when it does decide to go wrong it will do so in the worst possible way.)

My thoughts for Focus type for birding - AI Servo for Birds in flight, One shot for Birds at rest. Thats certainly the best in my experience with motorsport (not done birding but similar high speed objects)

so for a concert shooting which is best? AI focus, one shot, or AI servo?

If there is a lot of movement, AI Servo.

If the artists are fairly static, One Shot.

If you want to be frustrated, AI Focus

neilwood32 wrote in post #9702351
If there is a lot of movement, AI Servo.

If the artists are fairly static, One Shot.

If you want to be frustrated, AI Focus

Word...

JeffreyG wrote in post #6878918
AI Focus is for people who enjoy frustration.

hollis_f wrote in post #6881224
AI Focus is a combination of One-Shot and AI Servo. Unfortunatley it combines the bad points of each.

neilwood32 wrote in post #9702351
If there is a lot of movement, AI Servo.

If the artists are fairly static, One Shot.

If you want to be frustrated, AI Focus

All that. AI Focus tries One Shot until it discovers that's wrong, then it goes to AI Servo, just as your subject decides to stop, so it goes back to One Shot as it starts up again and . . . Well, you get the picture.

Jon wrote in post #9702458
Well, you get the picture.

Umm... no. Actually, you don't.

SoundsGood wrote in post #9702485
Umm... no. Actually, you don't.

Yeah you get a bundle of blurred frames.

neilwood32 wrote in post #9702351
If there is a lot of movement, AI Servo.

If the artists are fairly static, One Shot.

If you want to be frustrated, AI Focus

That about sums it up. AI Focus is about as useful as Auto AF point selection - letting the camera choose what it wants to do, which often has nothing in common with what you're actually trying to do.