This question was posted in Quora. It went on ‘ Golden Ratio = 0.618:1, Rule of Thirds gives 4 points … which are 0.66 units away from the edges of the container. If you look at it, 0.66 is pretty close to 0.618 and the difference might be imperceivable to the human eye.’
I thought it worth an answer, and this is what I said:
The similarity in the figures – both around 0.6 – is deceptive. There is a world of difference between the Golden Ratio (also Golden Section or Phi), and the Rule of Thirds.
In practical terms, Phi is a lot more interesting because it can be used to generate structures which are intuitively and innately harmonious, or look simply natural and ‘right’. From Phi you can generate a spiral that simulates the growth of snail or nautilus shells. With Phi you can sub-divide an image in many different ways e.g. each half divides into Phi ratio, and each portion can be sub-divided according to Phi ratios.
The amazing and wonderful thing is that when you apply these sub-divisions to natural forms as diverse as butterfly wings, animal faces and human faces, you’ll find major features are mapped to the main Phi divisions. Which suggests Phi is based on fundamental ways in which structures are generated.
Actually, Phi is demonstrable in music as well as other behaviours such as market behaviour. This is a far cry from the the simplistic Rule of Thirds. I always say that if you want your pictures to look the same as everyone else’s, follow the same rules as they do.
This topic is well worth a deeper discussion. I’ll work one up if you request it. In the meantime, check out Phimatrix for information on Phi as well as a dandy handy overlay application.