A week or so ago I was asked why archaeologists spend so much time preparing line drawing illustrators of things when photography is quick, cheap, and "more accurate". The answer is pretty easy, in fact. Some things are impossible to photograph. For example, Dimitri Nakassis and I spent an afternoon illustrating a wall uncovered by looters on our site. The only way we could reproduce the wall was to go down into a relatively narrow hole and produce a stone-by-stone illustration of the what we saw.
Likewise, as I have documented elsewhere, our illustration of the architecture at Pyla-Koutsopetria. Here a line drawing enables us to combine features that are not all visible at the same time in a photograph. In the drawing below, we were able to combine the results from excavation (at the far the southeastern and southwestern corners of the plan) with a stone-by-stone architectural drawing of the room and the plans produced by the architect at the time that the room was first excavated.
The images is, in effect, a historical composite of three different archaeological moments.