The rule of thirds is a "rule of thumb" or guideline which applies to the process of
composing visual images such as designs, films, paintings, and photographs.
The guideline proposes that an image should be imagined as divided into nine equal parts
by two equally spaced horizontal lines and two equally spaced vertical lines, and that
important compositional elements should be placed along these lines or their intersections.
Proponents of the technique claim that aligning a subject with these points creates more tension,
energy and interest in the composition than simply centering the subject would.
The photograph to the right demonstrates the application of the rule of thirds.
The horizon sits at the horizontal line dividing the lower third of the photo from the upper
two-thirds.
The tree sits at the intersection of two lines, sometimes called a power point or a crash
point.
Points of interest in the photo do not have to actually touch one of these lines to take
advantage of the rule of thirds.
For example, the brightest part of the sky near the horizon where the sun recently set
does not fall directly on one of the lines, but does fall near the intersection of two
of the lines, close enough to take advantage of the rule.
Use
The rule of thirds is applied by aligning a subject with the guide lines and their intersection
points, placing the horizon on the top or bottom line, or allowing linear features in
the image to flow from section to section.
The main reason for observing the rule of thirds is to discourage placement of the subject
at the center, or prevent a horizon from appearing to divide the picture in half.
Michael Ryan and Melissa Lenos, authors of the book An Introduction to Film Analysis:
Technique and Meaning in Narrative Film state that the use of rule of thirds is "favored
by cinematographers in their effort to design balanced and unified images".
When filming or photographing people, it is common to line the body up to a vertical line
and the person's eyes to a horizontal line.
If filming a moving subject, the same pattern is often followed, with the majority of the
extra room being in front of the person.
Likewise, when photographing a still subject who is not directly facing the camera, the
majority of the extra room should be in front of the subject with the vertical line running
through their perceived center of mass.
History
The rule of thirds was first written down by John Thomas Smith in 1797.
In his book Remarks on Rural Scenery, Smith quotes a 1783 work by Sir Joshua Reynolds,
in which Reynolds discusses, in unquantified terms, the balance of dark and light in a
painting.
Smith then continues with an expansion on the idea, naming it the "Rule of thirds":
Two distinct, equal lights, should never appear in the same picture : One should be principal,
and the rest sub-ordinate, both in dimension and degree : Unequal parts and gradations
lead the attention easily from part to part, while parts of equal appearance hold it awkwardly
suspended, as if unable to determine which of those parts is to be considered as the
subordinate.
"And to give the utmost force and solidity to your work, some part of the picture should
be as light, and some as dark as possible : These two extremes are then to be harmonized
and reconciled to each other."
Analogous to this "Rule of thirds", I have presumed to think that, in connecting or in
breaking the various lines of a picture, it would likewise be a good rule to do it, in
general, by a similar scheme of proportion; for example, in a design of landscape, to
determine the sky at about two-thirds ; or else at about one-third, so that the material
objects might occupy the other two : Again, two thirds of one element, to one third of
another element; and then both together to make but one third of the picture, of which
the two other thirds should go for the sky and aerial perspectives.
This rule would likewise apply in breaking a length of wall, or any other too great continuation
of line that it may be found necessary to break by crossing or hiding it with some other
object : In short, in applying this invention, generally speaking, or to any other case,
whether of light, shade, form, or color, I have found the ratio of about two thirds to
one third, or of one to two, a much better and more harmonizing proportion, than the
precise formal half, the too-far-extending four-fifths—and, in short, than any other
proportion whatever.
I should think myself honored by the opinion of any gentleman on this point; but until
I shall by better informed, shall conclude this general proportion of two and one to
be the most pictoresque medium in all cases of breaking or otherwise qualifying straight
lines and masses and groupes [sic], as Hogarth's line is agreed to be the most beautiful, medium
of curves.
Writing in 1845, in his book Chromatics, George Field notes that Sir Joshua Reynolds gives
the ratio 2:1 as a rule for the proportion of warm to cold colors in a painting, and
attributes to Smith the expansion of that rule to all proportions in painting:
Sir Joshua has given it as a rule, that the proportion of warm to cold colour in a picture
should be as two to one, although he has frequently deviated therefrom; and Smith, in his "Remarks
on Rural Scenery," would extend a like rule to all the proportions of painting, begging
for it the term of the "rule of thirds," according to which, a landscape, having one third of
land, should have two thirds of water, and these together, forming about one-third of
the picture, the remaining two-thirds to be for air and sky; and he applies the same rule
to the crossing and breaking of lines and objects, &c.
Even at this early date, there is skepticism over the universality of such a rule, at least
in regards to color, for Field continues:
This rule, however, does not supply a general law, but universalises a particular, the invariable
observance of which would produce a uniform and monotonous practice.
But, however occasionally useful, it is neither accurate nor universal, the true mean of nature
requiring compensation, which, in the case of warmth and coolness, is in about equal
proportions, while, in regard to advancing and retiring colours, the true balance of
effect is, approximately, three of the latter to one of the former; nevertheless, the proportions
in both cases are to be governed by the predominance of light or shade, and the required effect
of a picture, in which, and other species of antagonism, the scale of equivalents affords
a guide.
Smith's conception of the rule is meant to apply more generally than the version commonly
explained today, as he recommends it not just for dividing the frame, but also for all division
of straight lines, masses, or groups.
On the other hand, he does not discuss the now-common idea that intersections of the
third-lines of the frame are particularly strong or interesting for composition.
See also
Golden ratio Headroom
Lead room Rabatment of the rectangle
References