If I set any periferal point as starting point then 1Dx autofocus OK initially but not tracking the object. This is not very convinent in many situations when object is moving accross the frame and I want to catch it at one side of the frame and track it without camera movement while it crossing the frame.
What AF selection mode are you using? You need to be in 61-pt auto selection for it to track across the frame (in AI Servo, you can still select the starting AF point in 61-pt auto).
I'm curious, does that type of tracking provide any hitrate at all? I've briefly tried it, but feel it's like the lottery... any other setting to accompanie that mode for better accuracy?