AI Servo and AF Points

[hnoel]

When shooting motion (wildlife) and using the AI Servo setting, is it better to use all AF points, or keep with the center focus?

 

[KmH]

That will depend on how many cross-type focus points your particular camera has.

 

[hnoel]

I have 19 cross-type, 45 total points.

 

[Garbz]

Depends entirely on your wildlife, how well you track it, how good the autofocus system is, etc. On my D200 I try using the centre 5 point, on a D300 I let it pick any point assuming the background is featureless enough to make sure that the camera knows not to focus on that.

Really the right way to do it is to go out, use them both, and get a feel for what they do. Then either use whichever works best for the situation, or whichever you're best at using.

 

[KmH]

hnoel doesn't seem to want to provide much information. My skills are lacking when it comes to reading minds.

I'm guessing the camera is a Canon since Nikons doesn't make any cameras with 45 points?

So, hnoel we're willing to help but............are you trying to shoot BIF or what? What camera aand lens(s)are you using?

 

[Overread14 2]

I would second what Garbz said - AF works by finding the closest thing it can focus on and focusing on that subject. If your in woodland or shooting into reeds for example then I would stick to the centre AF point (or if you have time select an alternative single crosstype af point if you wish to compose off centre). If shooting into more open space like on flat plains or into the sky then all the AF points would be a better choice - especailly since it gives you far more freedom to compose offcentre.

 

[Garbz]

Just a quite note, AF systems haven't exclusively picked the closest point in a long time. These days AF is as complicated as matrix metering using various things like exposure to determine what the actual subject is.
Even my 4 year old Nikon has the option to prioritise center weighted autofocus, or pick the closest subject, and by moderns standards it's an incredibly primitive system.