AI Servo AF on 5D3

[stephen_bull]

Hi

 

I have been trying to use the AI Focus and AI Servo modes on my Canon 5D III but can't get them to do what I want.

 

When I focus on a moving subject in AI Servo mode the camera focuses on the moving subject, say a person walking towards me. If I

move the focus point so to create an off-center picture of the subject the focus changes to the point where the AF focus point has moved

to. Can I photograph off-center moving subjects? Am I missing something?

 

I am using a Canon 28-300mm lens with it which has 2 stabilisation modes. Setting 2 for moving subjects. It doesn't seem to matter what

setting I use on the lens I get the same result.

 

Any help appreciated

 

Thanks

Steve

[kerry_grim]

The quick answer for photographing an off-center moving subject is to change your focus point to the off-center position you want to focus. Either that, or crop the photo accordingly. It takes some practice to quickly change the focus point to the one you prefer.

[stephen_bull]

Thanks, I feared as much.

[paddler4]

<blockquote>

<p>I feared as much</p>

</blockquote>

<p>There is no reason to be put off by this. It's very simple to do on the 5D3, and the large number of good AF points is one of the major advantages of that camera over many others. the 5D3 is highly customizable, so you can set this a number of ways. I have mine set so that I just have to jog the multi-controller to move among the AF points. You can also set it so that the manual selection of AF points is limited to the 41 cross-type ones (see p. 99 of the manual). For example, if I am going to be photographing people and want to focus on faces, I just push the multicontroller to select the highest AF point. The only part of this that takes effort is plowing through the manual and settings to get the camera customized to do this the way you find easiest. Then it is simple.</p>

[peter_langfelder]

<p>I haven't shot with 5D Mark III but the iTR AF is supposed to be able to stay on subject by switching between focusing points when subject moves within the frame. You just have to make sure that the subject is under active AF point at the start.</p>

[stephen_bull]

Thanks. I get the idea but will need to play around with it a bit more.