03.04 Cartesian lines - horizontals and verticals

Two types of line - the horizontal and the vertical - deserve special attention, because together they:

• comprise the Cartesian axes on an Euclidean plane (photographs and paintings are generally presented in two dimensions); and
• become the frame of the viewfinder.

Horizontal lines
These are the most comfortable for us to view. This is because our natural field of vision is biased towards:

1. scanning from side-to-side; and
2. perceiving horizontal depth,

as a consequence of the lateral arrangement of our eyes. Horizontal lines convey a sense of stability and calm, of having lower energy, of something coming to rest from the effects of gravity - the properties associated with a base-line. The horizon is the most common horizontal line which we are exposed to.

Vertical lines
There is a higher energy cost for us to perceive in the vertical plane. Scanning from top-to-bottom and perceiving vertical depth often necessitates a tilt of the head: a weighty structure whose stable articulation under gravity consumes not inconsiderable energy. Vertical lines convey a sense of movement, speed and energy: of something falling due to gravity or moving to overcome its effect.

Horizontals and verticals in combination
Horizontal and vertical lines complement each other because they:

• act as natural stops to each other's movements; and
• create balance, of an upright being supported by a baseline.

When using these Cartesian axes, attention must be paid to align them exactly with the image frame, because their easy comparison renders misalignments glaringly obvious.