OK, “torture test” might be overstating things just a bit, but I’ve been meaning to check out a few things related to the capabilities of the autofocus system of my new Canon EOS 5DS R. A few years ago birds, especially winter migratory birds, became one of my photographic passions. While this camera is not really optimized for this sort of photography, I plan to use it for this purpose, as I did my 5DII.

Most often when I photograph birds I use the Canon EF 100-400mm f/4.5-5.6L IS II lens. It usually provides enough reach for my purposes, it focuses accurately and quite quickly, it is sharp, and its flexibility fits my style of photography. (I often pause while photographing the birds and use the lens to photograph landscapes.)  It was my understanding that the 5Ds R added the capability to autofocus (AF) at smaller apertures down to f/8. This means that I should be able to add my Canon Extender EF 1.4x III tele-extender to get 560mm at f/8 from this lens.

A few days ago I was doing landscape/seascape photography along the Central California coast between lower Big Sur and San Francisco. On the final afternoon as we drove north we passed a small island where scores of brown pelicans had landed. Continue reading The Canon 5Ds R — Autofocus ‘Torture’ Test →