How the visual world appears is important to me. I'm always aware of the light. I'm always aware of what I would call the 'deep composition.' Photography in the field is a process of creation, of thought and technique. But ultimately, it's an act of imaginatively seeing from within yourself.

I had luck, but I worked hard and I suffered. It's not just photography I'm talking about. It's about whatever dream you want it to be.

I did a story for the Geographic on Meriwether Lewis and William Clark, and Stephen Ambrose was the writer. He said, "I've got the easiest job in the world. I just have to re-tell the story of the greatest fishing, camping, hunting, canoeing trip of all time. You, Sam, have the hardest job, which is, pretend like nothing has happened in the last 200 years.

But there is more to a fine photograph than information. We are also seeking to present an image that arouses the curiosity of the viewer or that, best of all, provokes the viewer to think-to ask a question or simply to gaze in thoughtful wonder. We know that photographs inform people. We also know that photographs move people. The photograph that does both is the one we want to see and make. It is the kind of picture that makes you want to pick up your own camera again and go to work.

There are a lot of ways to talk about the life of a photograph. You can talk about the afterlife of a photograph, and in the end I talk about that, with the Richard Prince picture. But mainly, what I dedicated the book to being about was how photographs begin their life, and where they begin it. And they begin it with the photographer's imagination and instinct and experience.

First of all, I appropriate photographs.In presenting the Richard Prince photograph I tried to be as neutral as I could be. I put down the fact of it. I wanted it to be the same thing he wanted it to be, an open ended invitation to think about authorship, and who owns a created work. So I pair it with my appropriated picture.

It's more difficult now, to be a Geographic photographer, than it was when I came along. And it wasn't easy at that time.