Outside our complex is a small pond along an access road. There usually are a lot of Canada Geese here, but scattered along the far shoreline in the pond are Great Egrets, Great Blue Herons and Cormorants. Also a few shore birds are working along the edge. It is down a slope from the road, so you are sort of shooting down at them from quite a distance so you need a long lens to photograph them. Because of the distance I was using a Tamron 150-600mm lens with a Sigma 2X teleconverter for a 1200mm field of view to fill the frame more with the birds. I am surprised the Canon R autofocuses quickly with the combination of a 2X Teleconverter on a f/6.3 zoom lens. With the 2X teleconverter on the Tamron 150-600mm f/6.3 lens, my wide open f/stop was f/13. So I stoped down to f/16 to help with shrapness. My Canon 1D Series bodies would not autofocus past f/11 if you stacked teleconverters.