Leonardo Da Vinci painted the Lady with an Ermine with specific scientific goals in mind. He was exploring the effects of light on a subject, and the lighting seen here is so precise that one can calculate the distance the light is placed from the subject in the painting. Only by understanding light could a true 3D representation be made on paper. Other works of the time played very little with depth, especially in representing the facial features of a human. These often appeared bland, with every contour equally visible and under the same color shade. Unlike these two-dimensional representations, the Lady with an Ermine is situated with her body at an angle and there are clear gradients of light across her face and chest. This attention to detail by observation of the natural world parallels the focus in medicine and other scientific fields (in which Da Vinci was directly involved)