When composing an image, the addition of geometric patterns or basic shapes such as lines, circles, squares and triangles can add structure and organization within that photograph. It can help the photographer convey an idea or feeling to the viewer. The overall purpose of this is simple, to keep the viewers eye within the frame of the image. The viewer may perceive only a “pleasing image” without ever knowing or asking why.
There is a psychology behind the use of geometric patters in art and how the human mind perceives each of these shapes. Geometric shapes have been used in all types of art throughout the centuries and photography is no exception. The human mind perceives squares and rectangles to suggest conformity. Circles suggest completeness, triangles represent tension and lines represent movement. Be aware there are variations of these shapes such as vertical versus horizontal lines versus diagonal with each representing something different but the basic idea is the same. The goal being to engage the viewer.
There are two basic forms of geometry in photography, true and perceived. A true form would be the rectangular window or doorway on a house. A perceived triangle could be three people in an image that when connected by an imaginary line form a triangle. Which form is used weather perceived or true depends on the opportunity presented to the photographer at the time.
This is one of the techniques used in composition. Examples of other techniques used include the use of opposing colors and perspective Again, depending on the subject, intent and overall goal of the message to be conveyed by the photographer will determine the technique used.
The above image shows an example of use of a few geometric shapes within an image. Also note the the image is in black and white to place emphasis on the shapes rather then the color version which may distract the viewers attention from the basic geometric shapes.