Following Barthes...

Barthes begins Camera Lucida by explaining why he has a hard time finding "his" photographer. This leads to why some photos are hard to learn, if that makes sense. He then begins to give a few terms to describe what he sees in almost every photograph. He describes that the studium is the personal interest that the Spectator has for the photograph. However, seeing a studium within the photograph is only the tip of the iceberg when viewing a photo.

He says that he wants to find something in the photograph that wounds him. He calls this part of the photograph the punctum. The punctum, according to Barthes, is what sets it apart from everything else. He explains that it could be two different types of workers (Nuns and Soldiers) or something just as simple as someone's shoes (the Mary Janes).

He continues to explore these two terms as the essay goes on, and uses most of the pictures to use the terms. For example, he explains later that the studium and puntcum are related to the Spectator. The Observer was only there at that brief moment in time that allowed him to create the snapshot. To me, this is pretty much how the essay developed. It seemed it went from one term, to another, then back to the original. Sometimes the name might have changed, but in the end it was still basically the same thing.