Fibonacci spiral above a photo by Henri Cartier-Bresson. Source: Eric KimObjectivity vs Subjectivity: What Makes a Great Street Photograph?

Here’s what Mr. Cartier Bresson had to say on the subject in “The Decisive Moment“:

In applying the Golden Rule, the only pair of compasses at the photographer’s disposal is his own pair of eyes. Any geometrical analysis, any reducing of the picture to a schema, can be done only (because of its very nature) after the photograph has been taken, developed and printed – and then it can be used only for a port-mortem examination of the picture. I hope we will never see the day when photo shops sell little schema grills to clamp onto our viewfinders; and that the Golden Rule will never be found etched on our ground glass.

Curiously this is exactly what has happened. All three of my digital cameras allow various grids to be superimposed on the viewfinder. Thenkfully it’s possible to turn off the grids rather than have them etched permanently on “our ground glass”.

The above picture is taken from a long (4000 plus words) post on Eric Kim’s blog. It contains many other pictures, several of which have similar geometrical shapes on them. I guess Mr. Kim is engaged in exactly the kind of “post mortem” that Cartier-Bresson talks about. It seems clear that whatever “rules” Cartier-Bresson followed he wasn’t thinking about them too much at the time he pressed the shutter. Possibly he had absorbed them to such an extent that they were such a part of him and had become intuitive. Or maybe he was just a natural.