One of the great fortunes of living in Washington, DC is being able to walk down to the National Gallery of Art, enter at no cost, and wander the grand halls to view a rare Van Gogh. I did that on a recent Saturday and after viewing “Green Wheat Fields,” I happened upon an an exhibit of the photography of Charles Marville, a relatively obscure French photographer from the mid-1800s. Click to read more about how Marville’s photography photography captured a changing Paris.