The photos are interesting from a lighting perspective. All of them were taken in the same room. As I have said before, the coloration of red dogs is an evolving, revolving light show anyway, and different lighting makes the red tones even more interesting. The 1st and 3rd photos, the older Owl and Nexus, have more artificial lighting, because Owl claimed the couch and Nexus the dog bed which are further from the patio door. 2nd and 4th photos, Taya and Viljo, were taken on the carpet nearer the natural lighting from the glass door. Natural light is really beautiful, isn't it.