1D mk IV autofocus setting

I haven't had much of a chance to try out AI Servo AF on the mk IV. The little bit I have suggests it works, and if there is a limitation it's me!

I was wondering if anyone has had a chance to try out C.Fn III-8 AF expansion with selected point? It is disabled by default but settings 1-3 allow the AF to shift from the selected AF point to adjacent points or the whole array of 45 points. On paper this seems like it might work- you start out with AF on centre point on or near the eye of the bird, then as you track the flying bird you miss the target and the setting then shifts the AF point for you. However, what if it shifts backwards to somewhere on the body of the bird or the wing, rendering the eye OOF? Or will it shift backwards- C.Fn III-4 AI servo tracking method is set be default to track the closest object which is often the front of the head as the bird flies towards you.

Anyway, sorry for the ramble. Any observations would be useful.

I have C.Fn III-8 at center plus surrounding points, and haven't experimented much with all 45 points, it might cause problems with varying BGs and birds in flight.

C.Fn III-4 works best at 0 in my experience. On the Mark III, I had it at 1.

Tracking sensitivity is another setting that makes a difference, I have it at moderately slow for now. I read that some people leave it at 0.

I'm still waiting on a 1D4 and have never owned a 1D series camera - so can't make any recommendations. This link has recommendations to help in determining proper setting for your application.

http://www.wildlifeimagesbyles.net/T...cus_guide.html

Thanks David. Very useful!

I am also using center and surrounding points as assists. I have tracking sensitivity set to zero. The other day I was in Lake Placid and photographed bobsleds at 60 + MPH with super results. I hopt to have time to post images soon.