Stars and early morning light on Bandon Beach, Oregon. In extremely low-light situations, the 5D Mark IV’s ISO capabilities expanded my photographic options, as demonstrated in a pre-dawn image using a 30-second exposure at ƒ/5.6, ISO 6400. Canon EOS 5D Mark IV with Canon EF 11-24mm f/4L USM lens at 24mm.Before a new camera is announced by Canon, it is quietly vetted by a few photographers—typically among the group known as Canon Explorers of Light—whose work is particularly relevant to its capabilities. This period of intense field testing by the professionals allows for late-production tweaks. Next, a few pre-production cameras are assigned to some of the Explorers so that they can capture a variety of images for the camera’s initial promotion. And that’s where the fun starts. In the months preceding the release of Canon’s new full-frame DSLR, the EOS 5D Mark IV, I was fortunate to be involved in both aspects, evaluating the initial configuration and producing marketing images from ..