Photography is awash with rules, from the inverse square rule to the Sunny 16 rule; and nestling among the composition rules in the golden ratio. But what exactly is it? And what makes it compositionally valuable?
The golden ratio is a mathematical principle that you might also hear referred to as the golden mean, the golden section, the golden spiral, divine proportion, or Phi. Phi, a bit like Pi, is an irrational number. It is valued at approximately 1.618. As a ratio, it would be expressed as 1:1.618. A rectangle that conforms to the golden ratio would have shorter sides equivalent to 1 and longer sides equivalent to 1.618.
You get there by dividing a line (c) into parts (a) and (b) where (a) divided by (b) is equal to (c) divided by (a). Does a diagram help?