Washing and Grazing with Light
Light can be used in numerous ways to create effects, moods and drama, and this post introduces the techniques of washing and grazing with light.
Washing is a popular lighting design technique, and is used primarily for the illumination of large vertical surfaces and walls.
The method uses uniform indirect lighting to illuminate the specific area, and is used to hide any blemishes and imperfections. It does this by eliminating any shadows caused by the blemishes.
Wall washing tends to make the walls and room seem higher, larger and more spacious. It also makes the environment brighter.
In order to create uniformly distributed light across the whole area that needs to be washed, the luminaire(s) need to be installed at a certain distance away from the surface.
Grazing light is directional light at an acute angle, and can be used in both horizontal and vertical planes.
Grazing lights are placed much closer to the surface to be illuminate, and therefore the beam of light hits the wall or subject at a much narrower angle.
This produces shadowing that accentuates the texture and materiality of the surface of the wall or façade. Graze lighting solution will have a much narrower angle of beam than wash solutions, and provide a continuous narrow blade of light.
Internal and External Wash and Graze Solutions
Washing and grazing with light are techniques that can be applied internally or externally, and a variation of factors will determine which actual products are used.
Factors that could be relevant are:
• Whether white light or coloured light is required
• The light output required
• The dimensions of the area to be illuminated
• The physical size of the luminaire
• The beam angles available
• The dimming features
• Availability of mains power
• The cost of the solution
What Colour Can Be Used To Wash or Graze?
Washing and grazing with light can now use virtually any colour.
White light solutions tend to specify the colour temperature that will be required.
Colour temperature is a term used to describe the colour appearance of a lighting source, and it is measured in degrees Kelvin (K). Light sources that have a colour temperature of between 2000K to 3000K are considered to provide a ‘warm’ light. ‘Cool’ light sources are in the range of 4000K to 7000K.
Warm lighting (lower colour temperature) is often used to promote a feeling of relaxation. It is often used in restaurants, bars and lounge areas.
Cool lighting provides a brighter, cleaner light. It is often used in offices and work environments to enhance concentration and provide sufficient illumination to carry out tasks.
Colour temperature is only used when specifying white light solutions.
A Summary of Washing and Grazing With Light
Washing and grazing with light helps to bring walls or features to life.
Wall washing will illuminate the wall at a wider angle and ‘wash’ out the details and imperfections of the wall.
Washing is ideal for creating visually smooth surfaces
Grazing will light the wall at a narrow angle, and accentuate details.
Grazing is ideal for enhancing the visual characteristics of textured surfaces such as stone, brick or ironwork.
Washing and grazing can use white light or coloured light.