The golden section

Astonishing golden section, f, which is found in the conceptual field of the euclidean geometry, the proportions of the human body, and in Fibonacci's study on rabbits , etc…

It appears also in the geometry of plants through the pentagon and the number of petals of numerous flowers. He is integrally part of the logarithmic spiral which forms the shell observed in nautiloids (2):

In the human body, the golden section is observed in the ratio between the height of the individual and the distance from navel to ground.
Fibonacci has found the golden section in the number of individuals in rabbit populations growing as terms of the series of the same noun, the ratio of a term to its preceding one tending towards f.
The golden section is therefore intrinsic to a vast number of natural forms and events. Thus is f part of the human feeling of proportion, as being naturally inscribed in the environment, in the geometric harmony, and in the balance of the internal living forces.
All those observations determine the size of most of my canvasses.
Although their width derives from pure intuition, the proportion between the width and the length is connected to the golden section, so harmony can be observed and explained.
The number f defines families of golden rectangles.
The two basic families are:

1st family:

2nd family:

Other families of golden rectangles and combinations of these different rectangles can be defined, the relationship of their dimensions being linked to the golden section (3).

The first family possesses a remarkable geometric property:
when in such a rectangle, a square of equal length to the width is drawn, the leftover rectangle is in the same proportions than the initial one:

How can one fashion pictorial composition from the golden section?
The geometric property presented above is operated in the series called "Spirals". The connection to the Fibonacci series is developed in the series called "Serial Paintings".

1. Le nombre d'or. M. Cleyet-Michaud. Que sais-je ? PUF.
Le nombre d'or. M. Neveux- H. Huntley. Editions Seuil. Points sciences.
2. Nautiloids: family of cephalopod molluscs of very ancient type, with a spiral shell divided in sections crossed through by a long appendix (siphon).
3. Le nombre d'or. M. Cleyet-Michaud. Que sais-je ? PUF. p.30. Le nombre d'or. M. Neveux- H. Huntley. Seuil Editions. Points sciences. pp. 219 et ss.