Rule of Thirds ≠ Golden Ratio or Golden Mean

Not Equal To

While the Golden Ratio has been and continues to be used in the world of art, it is not the same as the Rule of Thirds.

The Golden Ratio is known by many names, The Golden Mean, The Golden Section, Phi, The Divine Section, The Divine Proportion, etc.

It describes an aspect ratio X units by Y units where X is always 1 and Y is always 1.608339887 * X.

The Rule of Thirds, on the other hand, addresses how to parcel out the described area of that space.

Mona Lisa – Leonardo Da Vinci

Construction of the Golden Ratio:1. Construct a unit square (red).2. Draw a line from the midpoint of one side to an opposite corner.3. Use that line as the radius to draw an arc that defines the long dimension of the rectangle.

The Golden Mean / Golden Ratio

Drawing of Golden Ratio from Wikipedia.

11.6180339887

a + ba

=ab

=

Rule of Thirds

The Rule of Thirds takes the proportions of whatever space we allocate, (usually our viewfinder frame), and breaks it into three equal sections, horizontally and vertically to find pleasing insertion points for important image details.

The Golden Mean / Golden Ratio

Here one can see how the Golden Mean becomes the basis of a nautilus shell.

The Golden Mean / Golden Ratio

Here is where I erred during my presentation, in correcting the young lady who pointed out the Fibonacci Sequence. In fact, the Golden Ratio does illustrate that famous number sequence.

1 2 3 5 8 13

In it’s simplest form the Fibonacci Sequence spells out, beginning with 1, the sum of the previous two numbers.

My apologies.

http://en.wikipedia.org/wiki/Golden_ratio

Sources:

Wikipedia

http://goldennumber.net/Golden Number. Net

http://jwilson.coe.uga.edu/EMT669/Student.Folders/Frietag.Mark/Homepage/Goldenratio/goldenratio.html

Phi: That Golden Number

The Parthenon – Athens, Greece