at the heronry today on the Colorado River.
I am shooting these at a distance of ~150 yards, with a Canon EOS 5D Mark IV and the Canon 500 mm f/4 EF lens with the EF 1.4x III extender for an effective focal length of 700 mm, on a tripod-mounted gimbal head. I am stunned at the optical quality and ability to acquire tack-sharp tracking focus of this camera/lens under, admittedly, near perfect lighting conditions.