Behind the Frame – Marievale Tern

Gerry van der Walt All Authors Leave a Comment



Marievale Tern

Canon EOS 1D MK IV, 600mm, 1/1600, f/4 ISO 160 

Marievale, South Africa


A cold winter’s morning at the Marievale Bird Sanctuary gave us some interesting photographic opportunities last year. This Whiskered Tern kept me, and the autofocus of the 1D MK IV, busy for quite a while as it flew above the mirror like surface of the water. 


Rather than selecting a single focus point for tracking this relatively small subject, I made use of the “Ring of Fire” as Jay Collier from Canon professional Services in Australia likes to call it, to assist me in maintaining focus whilst panning at pretty high speeds. 


This focus mode (AF expansion w/selected point – Surrounding AF points C.FnIII:8:2) allows the camera to make use of the centre focus point and surrounding focus points to achieve focus whilst simultaneously allowing the camera to shift focus to any one of the surrounding points if it detects that the subject has moved off of the central point. This works particularly well in situations where the background is relatively un–cluttered.


If there is one field of photography that forced you to delve deeper into the custom menu functions of your camera than any other, it has to be bird photography!


Andrew Beck


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