Perception of gestalt
Before a property can be attributed to an object, the object itself must be recognised, that is to say, distinguished from its surroundings. This process of interpretation has been used to formulate laws according to which certain arrangements are grouped together to form shapes, i.e. objects of perception. These laws of gestalt are of practical interest to the lighting designer. Every lighting installation comprises an arrangement of luminaires - on the ceiling, on the walls or in the space. This arrangement is not perceived in isolation, but in forms or groups in accordance with the laws of gestalt. The architectural surroundings and the lighting effects produced by the luminaires produce further patterns, which influence in our perception of the space.
Closed form
An essential principle of the perception of gestalt is the tendency to interpret closed forms as pure shapes.
Proximity
Luminaires are grouped in pairs.
Four points are grouped to form a square.
From eight points on, a circle is formed.
Elements arranged close together are grouped according to the law of proximity and form a pure shape. The example on the left demonstrates that we first see a circle and then an arrangement of luminaires. The circles are arranged in such a strict order that the imaginary linking lines between them is not straight lines, but forms a continuous circle, not a polygon.
Inside
An arc makes a pure shape visible on the inside of the line.
Shapes that are not completely closed can also be perceived as a gestalt. A closed shape is always seen as being on the inside of the linking line - the formative effect therefore only works in one direction. This inner side is usually identical to the concave, surrounding side of the line that encloses the shape. This in turn leads to a formative effect even in the case of arcs or angles, making a pure shape visible inside the line, that is to say, in the partly enclosed area. If this leads to a plausible interpretation of the
initial pattern, the effect of the inner side can be significant.
Symmetry
When two square luminaires are added to the pattern of circular downlights, the arrangement is perceived according to the law of symmetry to form two groups of five.
In regard to symmetry, the perception of a form as a pure shape is based on simple, logical structure. On the other hand more complex structures belonging to the same pattern disappear into an apparently continuous background.
Shapes of equal width
Even without strict symmetry, it is possible to recognise a pure shape.
A similar result occurs in parallel shapes of equal width. This is not strictly a case of symmetry. A principle of order and organisation is, however, evident, allowing us to perceive a pure shape. Two parallel lines show similarity.
Continuous line
Law of gestalt relating to continuous lines. The arrangement is interpreted as two lines crossing.
A basic law of gestalt is to prefer to perceive lines as steady continuous curves or straight lines, and to avoid bends and kinks. Our preference to perceive continuous lines is so great that it can
influence our overall interpretation of an image.
Pure form
The downlight arrangement is grouped into two lines according to the law of pure form.
The arrangement is interpreted as two superimposed rectangles.
When it comes to two-dimensional shapes, the law of the continuous line conforms with the law of pure form. In this case, shapes are organised to create figures that are as simple and clearly arranged as possible.
Identity
Luminaires of the same type are grouped together.
Besides spatial layout, the structure of the shapes themselves is also responsible for their formation into groups. The shapes in the accompanying drawing are not organised according to proximity or axial symmetry, but in groups of identical shapes. This
principle of identity also applies when the shapes in a group are not absolutely identical but only similar.
