Pattern’s Name: Geometry. This is really a set of patterns that involves figures, lines and points (a.k.a Triangles, Squares, Rectangles, Cones, Pyramids, Lines, Leading lines, Curves, Diagonals, etc.)
Problem or Question: How to organize the content of a picture with familiar, regular, forms and shapes, and pointing or distinguishing to the main subjects?
Visual Elements: Geometrical shapes or figures (triangles, rectangles, cones, cubes, pyramids), lines (horizontal, vertical), diagonals, curves, explicit or implicit, are strong compositional visual elements that could organize the content in regular patterns leading to or framing the main subjects. If the figures and lines aren’t explicit (the content is not «geometrical»), the change of angle or perspective of the sight might draw an implicit line or figure. The elements might be disposed in different focal planes.
Solution: Use natural, explicit or implicit, shapes and lines to organize the frame content. Standard patterns are all types of lines, from horizontals, verticals, diagonals to curves, and basic shapes, triangles, squares and tridimensional figures, as cones or pyramids. This set of patterns have well-known instances that distinguish themselves and should be studied separately. The leading line, the converging lines and vanishing point patterns are instances of this set. In the leading line pattern, the line points to the main subject of the picture, starting from one edge of the frame (usually the bottom or left edge) to the subject. Most of those pictures are also converging lines and the subject is located exactly in the vanishing point. In some genres (architecture, e.g.), this compositional pattern is very natural. Buildings, interior and exteriors, are predominantly constructed by lines and geometrical figures.
It’s natural also to organize the composition with the Rule of thirds, aligning the dominant lines within the implicit grid that conforms the four lines. Also there’s the possibility to use the Rule of Odds with 3 elements forming an implicit triangle. Squared figures are the basis of another specialization of the pattern: the natural frame.
Technical implementation: Perfect horizontal or vertical lines could be settled within the grid in the viewfinder of modern cameras. Other cameras have an embedded level. For diagonals, it’s preferred to reach an approximate 45 degree angles, to manifest the explicit intention of the composition. When you want to show multiple planes in the composition, you need a closed aperture (f/8 or more), or take distance from subjects, and maybe use a short length lens, to obtain the proper depth-of-field.
The position of the camera, the perspective is the most important technical part, because it defines the visibility of the shapes and lines. The camera should be in the exact position where the shape is clearly defined. This is more important when the shapes and lines are implicit by the subject that populates the scene. The subjects are like points that connect the lines.
Examples: There are lots of images that use lines as a strong composition visual elements. They spread in all genres, from landscape and cityscape, to environmental portrait. Here are some examples:
This simple geometrical view of a building façade shows diagonals, polygons (diamonds) and the insinuations of multiple arrow shapes (triangles) with the balconies. The angled view is on purpose to put some dynamism in the perfectly squared façade. If you pay attention the arrows of the windows and the shade curtains point to the upper right of the frame.
This other pictures shows horizontal lines, diamond shapes, and ovals. Architectural pictures are natural for these patterns, and you can use a lots of perspectives with good results.
This other example, shows the use of a inner frame (a.k.a. sub-framing), in this case a fish-eye mirror, as a geometrical element defining the mood of the picture.