Fast, precise autofocusing paired with subject detection and tracking mean it's easier than ever to get a sharp shot of a moving subject using a Canon EOS camera. However, the decision to switch from one subject to another still rests with the photographer, and the process of recognising that there's a new, more interesting subject, then using your thumb to shift the focus point, can result in a slight delay that means a key moment could be missed.
Imagine, for example, that a cheetah going in for a kill suddenly comes under attack from a lion, or the favourite in a race pulls up short, or a protestor interrupts a political statement – these are all unexpected events that demand a shift in the photographer's attention and a change to the focus point. The first few moments are crucial to telling the story and it's essential that the focus switches quickly to the new subject. With the Canon EOS R3's Eye Control AF it's possible to switch between subjects just by looking where you want to focus in the viewfinder, rather than reaching for the Multi-controller and nudging the AF point across.
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