I breathe deeper when a viewfinder is pressed to my eye. As I'm depressing the shutter, I'm holding it, but the whole process and approach to that moment, respiarations are slow, even and deep. Walking and looking with intention is very much an act of meditation-- a very healthful practice.
I was in St. John's the other week on a walkabout that would end encircling the St. John's Bridge, and this fellow was having his lunch. I said, "May I?", and he said, "Of course." The cat didn't give his permission.