We were able to spend last Sunday in San Francisco, going first to see the Luminous Worlds: British Works on Paper 1760–1900 exhibition at the Legion of Honor, and then the J. M. W. Turner: Painting Set Free exhibition at the de Young. I’m not sure which museum store I saw it at, but when I got back to Ann Arbor I found Turner and Constable: Sketching from Nature in the local library system. As well as displaying a fabulous collection of landscape paintings, the book has proven highly educational for me. I knew that the Impressionists were able to go outside for plain air painting thanks to an advance in their technology, the invention of tin tubes for oil paints, making it much easier to transport and use paints and removing the need for each painter to prepare their own paints. What I didn’t know was that first of all that invention happened all the way back in 1841, and that many painters, despite the complexities and handicaps, had been painting outdoors since the 1750′s if not the 1650′s! Probably the most interesting for me was that the paintings presented seem to support my previous observations that Impressionist painters weren’t making some sudden departure from previous painting styles and techniques, but were more of a step on, albeit a big step maybe, from what had come before. Especially for the early plain air painters in this book, there just wasn’t the time to go into massive amounts of detail, in part because of their more primitive portable paints, the drying time, and so their paintings frequently have many of the same implicit rather than explicit presentation of the scene before the painter. From the perspective of photography, the other interesting thing the book illustrates is the late 18th century movement from romantic views of the countryside, with added elements from mythology, towards a more literal portrayal, a role that it could be argued was soon to be taken up, if not over, by photographers.