Technical improvements to the daguerreotype in the early 1840s took the world by storm as portrait galleries opened everywhere to meet demand. Martin Schoeller’s new book, Portraits, a 15-year retrospective of his modern portrait photography, is further evidence of the long-lasting power of the photographic portrait that began 175 years ago.

I caught up with the busy Schoeller to ask him about some of his favorite portraits that appear in his beautifully-printed new book. He highlighted some of the images that dip into conceptual territory—a place he very much likes to play.

“He deserved the cover,” Schoeller says of George Clooney. “It incorporates well with what I’m trying to do with this book—to take pictures that feel like portraits, but maybe not