Shining a light on a surface sounds on the face of it, an eminently straightforward task. In fact it's an extremely complex proposition given the number of variables and considerations. The nature, texture and colour of the material, the quality and type of light (cool/warm, direct/diffuse), the location, the juxtaposition with a different material or colour are just some of the basic factors that will affect the final outcome.
Matte materials will obviously react very differently to highly reflective ones, for instance, not only in terms of how they will appear but in how they distribute the light. A mirrored surface could be illuminated to the same level as one made of black velvet but the former would always appear much lighter, and rather than absorbing light would bounce it around the space.
Mark Ridler, BDP's head of lighting, recently put it very succinctly in an article for FX magazine: 'You can’t make a black wall white, no matter how much light you chuck at it.'
Similarly, a material such as a warm-coloured wood will lose its mellow tones if washed by a cool temperature source. A highly textured material or surface can be flattened out or brought to life depending on the position of the light source.
In other words you can't fight physics. To coax the best out of surfaces and materials, and therefore the ultimate composition and atmosphere of a space, it is essential to work with them. Basically that means considering the lighting and how it will work best with the interior elements at a very early stage. In that way sources and their location can complement them and, ideally, be integrated rather than bolted on as an afterthought.
'Lighting designers always factor in finishes, colour and texture of materials into their scheme but, unfortunately, a recurrent problem they encounter is that the actual finishes are not decided on early enough in the design process,' lighting consultant Kevin Theobald of KTLD once wrote. 'This means that the correct type of lighting may not have been specified, surfaces are literally not seen in their best light and making the necessary changes means added time and costs.'
Ridler has the classic example of precisely that. 'I once lit a hotel toilet entirely indirectly with the agreement of the interior designer. Unbeknown to me the ladies had been finished in gold and the gents in grey. Not surprisingly, one was three times brighter than the other on site. Rectifiable, but only by re-specifying – thus incurring extra cost/delay – and using more energy.
'We as architects, interior designers and lighting designers need to think about finishes earlier that we habitually do,' continues Ridler. 'Finishes are so much part of the character of a space, and in particular the tonality; they are so essential to the perception of form, that they should be key to the conceptual approach.'
The 'snow garden' in the spa at ZHA's Morpheus hotel, City of Dreams, Macau, is an exemplar of both use of materials and the way in which they are lit, in this case by Isometrix Lighting + Design. The rich, red tones and soft gleam of the surrounding wood panels are enriched by concealed warm temperature sources. By contrast the cool, reflective marble of the centrepiece snow garden with its silver birch is complemented by the chillier white tones of the hidden spotlighting. The composition is both apt and perfectly balanced.
Raw concrete has been a popular material for some time, though according to Mark Ridler absorbs around 70 per cent of the light, which can make it inefficient if used widely in a space. However concrete was used to dramatic effect at the Stella McCartney outlet in London's Old Bond Street and was central to the interior concept. 'A key direction of the brief was... to explore the use of industrial and natural materials and interpret them into a contemporary interior design,' says Phil Caton of PJC Light Studio, which created the lighting scheme (highly commended in the 2019 Lighting Design Awards).
The subtle, uniform wash which emanates from concealed sources at the base of the concrete walls on the staircase adds a stark drama, fully revealing the raw, industrial texture of the surface. 'The feature staircase had to be dramatic while creating a moment of calm and escape between the retail spaces, with reduced light levels to bring emphasis to the video projections,' says Caton.
As the second image shows, the cooler concrete is juxtaposed with warmer elements in a similar approach to the snow garden.
The most extreme example of the relationship between light and surface is where the two are fused together. Backlit walls and ceilings are the most obvious example, but in the case of the Enigma Restaurant, Barcelona, together they form an intrinsic decorative element. In a scheme by Davide Groppi, the diffuse effect of the cloud-like ceiling also allows a softer light to fall on the textured glass elements. The concept of translucency is echoed in the furniture.
If light levels are simply engineered with no reference to finishes, says Ridler, then they alone will be responsible for the role of sculpting the space. 'They will need to work very hard to meet the technical brief, create atmosphere, define form and visual hierarchy,' he says. 'It’s done a lot and sometimes very successfully – but the design is "dancing on one leg".'