Ludwig Justi’s “Konstruierte Figuren und Köpfe unter den Werken Albrecht Dürers” (1902) is the only study thus far that devotes itself closely to Dürer’s head constructions. In the work, the author considers ideally-constructed profile heads and frontal heads in order to establish similarities and deviations.
For Justi a “complete schema” was present when the head measured 1/8 of the body length and the face 1/10. The face was divided into three sections: chin to tip of the nose, nose to eyebrows, and eyebrows to hairline. These are the ideal measurements of Vitruvius (see The Rules of Vitruvius).
The Head of a Man was not part of the analysis at the time, but Justi supplied Campbell Dodgson with a preliminary, unclear schema in 1921. It was based on suppositions that are elusive today. The result is vague and not particularly ambitious. It underestimates Dürer’s quest for scientific innovation in painting.