Perhaps the toughest portrait of all would be a vigilant black dog at night. This photo of Ilsa was taken with available light after the sun had slipped beneath the horizon. The need for a big hole with big glass was evident, as I required the quickest shutter speed possible on the moving animal. The camera's auto focus was incapacitated by the task.
A photo of Cassie was easier, simply because of her lighter coat.
The money shot was a pic of Cassie looking up into the rustling trees. The complementary contrast between the lavender background and the golden coat make the photo. The contrast between the sharply focused head and the blur of a disconnected wagging tail is icing on the cake.
Nikon D-200, 85mm ƒ1.8