Highlights, the Middle Shadow, and the Power of Lights
A small strong light casts a darker shadow than a large weak one
This page of Book Five defines highlights (lustres) as sharply bounded features of the middle shadow when the primary light is a particular source. A short chapter argues that a small but powerful light produces a darker shadow than a larger light of lesser power. Leonardo then defines the 'middle shadow' as the tone tingeing a body's surface after the principal shadow, which contains the reflected light and grows darker or lighter with its nearness to the principal shadow; in the diagram the darkest shadow lies between m and n, brightening toward point o. A final chapter opens on how the eye's motion around a body changes how much shadow it sees. The page carries a running head and folio number.
On this page
Small strong light versus large weak light
The shadow generated by a small and powerful light is darker than the shadow born of a larger light of lesser power. The question raised is whether a great light of little power is worth as much as a small light of great power.
The middle shadow and its reflected light
The middle shadow is the tone that tinges the surfaces of shadowed bodies after the principal shadow, and within it the reflected light is contained; it becomes darker or lighter as it lies nearer to or farther from the principal shadow. In the figure the darkest shadow is m n, and the rest grows lighter up to the point o.