The artist determines what the centre of interest (focus in photography) of the art work will be, and composes the elements accordingly. The gaze of the viewer will then tend to linger over these points of interest.
The position of the viewer can strongly influence the aesthetics of an image, even if the subject is entirely imaginary and viewed “within the mind’s eye”. Not only does it influence the elements within the picture, but it also influences the viewer’s interpretation of the subject.
For example, if a boy is photographed from above, perhaps from the eye level of an adult, he is diminished in stature. A photograph taken at the child’s level would treat him as an equal, and one taken from below could result in an impression of dominance. Therefore, the photographer is choosing the viewer’s positioning.
A subject can be rendered more dramatic when it fills the frame. There exists a tendency to perceive things as larger than they actually are, and filling the frame full fills this psychological mechanism. This can be used to eliminate distractions from the background.
In photography, altering the position of the camera can change the image so that the subject has fewer or more distractions with which to compete. This may be achieved by getting closer, moving laterally, tilting, panning, or moving the camera vertically.
There are numerous approaches or “compositional techniques” to achieve a sense of unity within an artwork, depending on the goals of the artist. For example, a work of art is said to be aesthetically pleasing to the eye if the elements within the work are arranged in a balanced compositional way. However, there are artists such as Salvador Dalí who aim to disrupt traditional composition and challenge the viewer to re-think balance and design elements within art works.
Rule of thirds.
The rule of thirds is a composition guide that states that arranging the important features of an image on or near the horizontal and vertical lines that would divide the image into thirds horizontally and vertically is visually pleasing. The objective is to stop the subject(s) and areas of interest (such as the horizon) from bisecting the image, by placing them near one of the lines that would divide the image into three equal columns and rows, ideally near the intersection of those lines.
Rule of odds.
The “rule of odds” states that by framing the object of interest with an even number of surrounding objects, it becomes more comforting to the eye, thus creates a feeling of ease and pleasure. It is based on the assumption that humans tend to find visual images that reflect their own preferences/wishes in life more pleasing and attractive.
The “rule of odds” suggests that an odd number of subjects in an image is more interesting than an even number. Thus if you have more than one subject in your picture, the suggestion is to choose an arrangement with at least three subjects. An even number of subjects produces symmetries in the image, which can appear less natural for a naturalistic, informal composition.
An image of a person surrounded/framed by two other persons, for instance, where the person in the centre is the object of interest in that image/artwork, is more likely to be perceived as friendly and comforting by the viewer, than an image of a single person with no significant surroundings.
Rule of space.
The rule of space applies to artwork (photography, advertising, illustration) picturing object(s) to which the artist wants to apply the illusion of movement, or which is supposed to create a contextual bubble in the viewer’s mind.
This can be achieved, for instance, by leaving white space in the direction the eyes of a portrayed person are looking, or, when picturing a runner, adding white space in front of him rather than behind him to indicate movement.
Images with clutter can distract from the main elements within the picture and make it difficult to identify the subject. By decreasing the extraneous content, the viewer is more likely to focus on the primary objects. Clutter can also be reduced through the use of lighting, as the brighter areas of the image tend to draw the eye, as do lines, squares and colour. In painting, the artist may use less detailed and defined brushwork towards the edges of the picture. Removing the elements to the focus of the object, taking only the needed components.
Shallow Depth of Field.
In photography, one approach to achieving simplification is to use a wide aperture when shooting to limit the depth of field. When used properly in the right setting, this technique can place everything that is not the subject of the photograph out of focus.
Geometry and symmetry.
Related to the rule of odds is the observation that triangles are an aesthetically pleasing implied shape within an image. In a canonically attractive face, the mouth and eyes fall within the corners of the area of an equilateral triangle. Paul Cézanne successfully used triangles in his compositions of still life’s. A triangular format creates a sense of stability and strength.
It is generally thought to be more pleasing to the viewer if the image encourages the eye to move around the image, rather than immediately fixating on a single place or no place in particular. Artists will often strive to avoid creating compositions that feel “static” or “flat” by incorporating movement into the image.
In image A, the 2 mountains are equally sized and positioned beside each other creating a very static and uninteresting image. In image B, the mountains are differently sized and one is placed closer to the horizon, guiding the eye to move from one mountain to the other creating a more interesting and pleasing image. This also feels more natural because in nature objects are rarely the same size and evenly spaced.