One of the things that interests me about compositing, at least as it pertains to dog photography, is that it offers me the ability to tell a story about a dog that includes elements not be easily accessible to me here in the Denver area.
Compositing sometimes also requires me to train a dog to assume a posture or engage in an activity that it does not already know how to do. My image of the German Shorthaired Pointer jumping a horse fence with a duck-shaped retrieving dummy in its mouth required about four days of training (although the video makes it look like the training was accomplished in a day). My decade-plus experience as a professional dog trainer came in handy in this case.
But not all composite imagery is so complex as the one above. For instance, in my studio I will sometimes shoot in front of a green screen and then composite in a background.
In the image below, the dog was photographed in front of a green screen and an appropriate background was inserted after the fact.
Shooting in front of a green screen comes with potential problems. Lighting must be near-perfect. And even when it is, color contamination coming from light bouncing off the green screen has to be dealt with. But the up-side is that I have an infinite amount of backgrounds; they are limited only by my imagination.
While the vast majority of my photography work contains no compositing, I do enjoy experimenting with it. I find the limitlessness of it freeing.