which AF mode?

which auto focus mode do you use in which situation and why? you know one shot, A1 servo, etc...

which auto focus mode do you use in which situation and why? you know one shot, A1 servo, etc...

Which camera you using Matt? So we get the language right.

Steve

this question has come up before and you will find varying opinions if you search for it.

I use APS-C, which I think in Canon terminology is called Servo because fish move and I want my focus to move with them. It also gives me Shutter Priority instead of Focus priority (this can be changed deep in the cameras settings). On focus priority you can't fire the shutter if the camera thinks you are not focused, but it may be looking at a different subject than you.

Some say APS-S is better (maybe what you call one shot?) because they say the lens doesn't hunt as much. it finds its focus and stays in the same position, but won't let you fire the shutter until it finds its focus.

I'm using the 5D mk2. I actually read the manual but am now more confused. It sounds like A1 servo changes the focus as you shoot. So if I'm shooting a fish as it swims by, in A1 servo mode the camera adjusts the focus each time I hit the shutter release. In the other mode, the focus is set on the first shot and will remain constant throughout the "burst" of shots... right?

One-Shot AF - single shot auto focus

AI Servo AF – automatic tracking of a subject approaching or receding at speeds up to 50 kph, from up to 8 metres** away

AI Focus AF – switches automatically between One-Shot AF and AI Servo AF modes based on subject movement, available on selected EOS models.

Hope this helps

Stew