A Treatise on Painting/Chapter 182
Appearance
Chap. CLXXXII.—How the Painter is to place himself in regard to the Light, and his Model.
Let A B be the window, M the centre of it, C the model. The best situation for the painter will be a little sideways, between the window and his model, as D, so that he may see his object partly in the light and partly in the shadow.