# Piero di Cosimo: "Portrait of Simonetta Vespucci" c.1490, Musée Condé, Chantilly, Detail: Face, and Golden Rectangles. Animation for iPad.

Successive Golden Rectangles dividing a Golden Rectangle into squares (logarithmic spiral known as the golden spiral)

Portrait of Simonetta Vespucci (c. 1490) by Piero di Cosimo
Oil on panel, 57 x 42 cm, p;Source: Wikipedia: Simonetta Vespucci.

Piero di Cosimo
Piero di Cosimo (1462 – 1522), also known as Piero di Lorenzo, was an Italian Renaissance painter. Piero was born in Florence and apprenticed under the artist Cosimo Rosseli, from whom he derived his popular name and whom he assisted in the painting of the Sistine Chapel in 1481. Read more.

Golden rectangle
A golden rectangle is a rectangle whose side lengths are in the golden ratio, one-to-phi, that is, approximately 1:1.618. A distinctive feature of this shape is that when a square section is removed, the remainder is another golden rectangle, that is, with the same proportions as the first. Square removal can be repeated infinitely, which leads to an approximation of the golden or Fibonacci spiral.

Droste Effect
The Droste effect is a specific kind of recursive picture, one that in heraldry is termed mise en abyme. An image exhibiting the Droste effect depicts a smaller version of itself in a place where a similar picture would realistically be expected to appear. This smaller version then depicts an even smaller version of itself in the same place, and so on. Only in theory could this go on forever; practically, it continues only as long as the resolution of the picture allows, which is relatively short, since each iteration geometrically reduces the picture's size. It is a visual example of a strange loop, a self-referential system of instancing which is the cornerstone of fractal geometry. Source: Wikipedia, Droste Effect.

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Aug 9, 2014