The Golden Section (also known as the Golden Ratio, Golden Mean and the Greek letter Phi) relates to a mathematical theory of composition, which has been used for centuries as a means of creating balanced, harmonious proportions in paintings, drawings, design and architecture.
The golden ratio (1 to 1.6180339887 to be exact) describes the relationship between two proportions. Fibonacci numbers, like many elements found in nature, also follow a 1:1.61 ratio (think about the spiral of a shell or the seed head of a sunflower). It may be that because this ratio frequently occurs in nature, it helps to make a layout look right and natural to our eyes.
It works like this:
Divide the width of the canvas by the Golden Ratio. Mark this with a horizontal line. This line will divide the canvas into one third and two thirds.
Then divide the height of the canvas by the golden ratio and mark this up as a horizontal line in the smaller section, and so on and so on. The images below show this much more clearly than I can describe.
The idea is that key elements of a painting or drawing map to the ‘grid’ – which is traditionally illustrated with a Fibonacci spiral. The Golden Section may apply to the whole of the canvas and / or individual sections within it.
Rule of thirds
The ‘rule of thirds’ is a related and slightly easier concept and states that by dividing an area into equal thirds both vertically and horizontally, the intersection of the lines will provide natural focal points. Photographers and designers are taught to position their key subject on one of these intersecting lines.
Although the rule of thirds can be applied to any shape, if you apply it to a rectangle with proportions approximately 1:1.6, you get very close to a Golden Rectangle, which, so the theory says, makes the composition all the more pleasing to the eye.
Essentially this concept says that a perfectly symmetrical composition works less well than one that is slightly asymmetrical.
Rules that must be obeyed?
The Golden Section and Rule of Thirds are useful guidelines to be aware of and particularly handy to think about if a composition isn’t looking quite right. They are not absolute rules and not every successful composition adheres to them. It’s fine to rely upon a sense of what looks right, particularly if you have an experienced eye. Also, different shapes of canvas can support different types of composition. For example, a symmetrical composition may work perfectly well for a square format.
Photography course with Frank Wong in 2013 delivered via http://www.skillshare.com