When composing digital media, composition rules are used to draw the viewer’s attention to features of interest and to make an image more aesthetically pleasing.
Rule of thirds
The ‘rule of thirds’ composition is the concept that an image is split up into nine equal parts – with two lines in each axis dividing them. By placing subjects of interest along these lines and where they intersect, it draws the observer’s attention to these points. Also, by putting the horizon of an image along one of the horizontal thirds, it adds a complexity to the image where putting it in the middle would leave it too symmetrical.
Sometimes referred to as a less simplified version of the rule of thirds, the golden ratio is based on the mathematical Fibonacci sequence and appears in both nature and science. This could be why images using this spiral, or rectangle tend to have a more organic feel to them.
An example of leading lines would be railway tracks running off into the distance, sometimes towards an object of interest. Unlike the two previous compositional layout techniques, leading lines tend to guide the view along a path rather than to a fixed point.