In 1988 the master plan for the Night Safari project was in preparation, when lighting was first considered.  What was to become a perennial discussion was the issue of whether the lighting for Night Safari should be designed by an engineer or an artist.  We are happy to report that the latter was selected, and so a theatrical lighting designer came to be involved in the Night Safari project.

My (S.C.) regular work varies from ‘West End’ commercial theatre productions to shows at the Royal National Theatre and Avant Garde dance.

The habitat lighting consists of about 2,000 lights on 800 poles of heights between 4m and 12m.  Only one light fitting is used, with variations of lamp, filter and hood.  The exact location of every pole was determined on site, and every lamp is individually specified and focused.  The lighting of the ‘built environment’ follows a more familiar pattern but the quality of light was closely specified, leaving the architects to select fittings to co-ordinate with their schemes.

We will describe some of the specific issues and parameters to be considered when designing lighting for a ‘night-zoo’ situation, but first we would like to expand on the differences between an engineering approach and a creative one.  We exaggerate a little to make the point:

A lighting engineer designs lighting according to codes and recommendations, with some input from his personal experience and preferences.  He or she deals with illumination levels and uniformity, using formulae to calculate lighting results to given specifications, from given photometric and environmental data.  Their extraordinary achievement, which this lighting designer cannot begin to imitate, is to predict the results of a lighting installation by calculation.  Their plan can be installed and commissioned with little further design input, and the lighting will be more or less as anticipated.

By contrast, a theatrical lighting designer works towards a result by intuition and experience alone.  The objective is to create an environment with special atmosphere, in which people may be affected, and moved to suspend their disbelief.  Decisions are based on gut instinct and empirical tests.  I am frequently asked about lighting levels at Night Safari, and to this day I tend to fudge my answers because I don't know exactly.  (The range is generally between 10 and 100 Lux.)  More importantly: I don't really care, because for me the test of good lighting is “if it looks OK, then it is OK.”

None of this is to question the primary importance of visitor safety of course.  But we are all familiar with situations where codes are adhered to regardless, when an alternative approach might offer equal or better public safety.  In fact Night Safari has some very dark pathways which would cause safety officers concern in North America or Europe, but in the context, allowing for path surfacing and the illumination of surrounding vegetation and habitats, experience shows us that the paths are adequately illuminated and very safe.  There have been few complaints and no accidents attributed to dingy pathway illumination.

So, having appointed a lighting designer, the process begins. And as with all creative projects, every one is new, and demands a unique solution.  The following are a few of the points to consider when planning lighting, with particular reference to the Night Safari project as an example.

The question of style is of first and overriding importance. In a night-time facility everything the visitor sees will be determined by lighting.  The atmosphere and overall quality of the experience will be greatly affected by the lighting, as well as specific issues such as animal visibility.  An enduring difficulty when working as a lighting designer is how to describe the stuff.  It's not possible to draw it; lighting plans are just a bunch of symbols.  So we tend to resort to adjectives and examples from other media.  Film lighting is often a useful metaphor, and painting has a host of types to imitate.  “Like ‘The Third Man’” or, “a bit more ‘Whistler’” are common refrains at light meetings.

From a general approach to style we move on to the development of a lighting ‘concept’.  At this stage we begin to consider more carefully what sort of light we want and where is it coming from.  For Night Safari we decided to have a moonlight theme for the habitats and a firelight theme for the built areas, including small structures such as rain shelters.  This may seem an obvious choice, but at the time it caused some controversy as people took on board the idea that one could create a theatrical, or cinematic, moonlight which would provide viewing conditions superior to the real thing.

The moonlight theme demands a ‘cool’ feeling to the light, determined by our expectations rather than fact.  Actual moonlight is more or less the same colour as daylight, because the moon is a neutral reflector, but we expect it to be cool for cultural reasons: at the opera the moon is usually blue.  However, with artificial light our assumed ‘white’ is 3200K, the colour of an unfiltered tungsten halogen source.  So, conveniently, we can combine both of these facts to use incandescent light ‘corrected’ with a blue filter to 5000K, providing a theatrical ‘cool’ which happens to be similar to the colour of real moonlight.

Another colour issue is monochromaticity, a result of very low light levels, when only the rods in the retina operate.  This raises an interesting debate about colour rendering. Zoo people are keen to describe and witness the colours of animals; but on a ‘real’ moonlit night one would not be able to distinguish colours at all.  Only shapes and textures would be visible.  This effect cannot be reproduced at higher light intensities, but it can be some justification for dubious colour rendition.  Night Safari uses about 50% mercury discharge lighting for a variety of reasons, including energy saving, low maintenance, and reliability.  A particular lamp was selected after extensive field testing which gives a pleasing result on jungle foliage and tolerable results on animals and people.  This lamp has rather poor colour rendition by modern standards, but it does have a certain ‘feel’ which makes it suitable in this application.

Colour temperature described in degrees Kelvin is a theoretical idea based on the absolute temperature of an ideal ‘black body radiator’. Strictly, only incandescent sources can be described in these terms, all of which, by definition, offer perfect (although different) colour impressions.  The essential difference between an oil-lamp lit interior and a moonlit exterior is one of colour temperature: the interior seems warm and orange, while the exterior appears cool and blue, but by comparison only.

The presence of different colours in an environment, and their colour contrast, reinforce the impressions of colour and quality outlined above.  In the Night Safari, buildings were fitted with dimmed incandescent lighting: dimming significantly lowers the colour temperature, increasing the ‘warmth’ of the light and adding to the impression of coolness experienced outside in the habitats. Dimming also greatly extends the life of incandescent lamps.

Another essential feature of moonlight is that it emanates from above, where the moon is.  This requires either pole or tree fixings.  The dappled patterns of branch and leaf on the ground and the fall of animal and landscape shadows all add to the moonlight impression.  Virtually all the lamps at Night Safari are fixed on poles; tests demonstrated that trees were just too much bother to use on a large scale, despite apparent cost savings.  Trees keep falling over in tropical storms, the cable routing is ugly, and access is very awkward.

Poles on the other hand are very convenient and, especially in a night-only installation, not too imposing.  Again field-testing was used to determine the optimum heights and distribution of poles.  Tests were carried out at up to 25m: an exciting evening dangling in a crane bucket. This offered very interesting results, in that the light for a whole enclosure might come from effectively one point.  But the disbenefits were several: the distant view of such a high cluster of lights led one observer to compare the scene to a football stadium.  The flexibility to fill shadows and create sophisticated pictures is severely restricted, and the cost savings are not great given the exponential rise in pole costs over about 15m.  Most poles at Night Safari are 8m or 10m, with some at 4m, 6m, and 12m.  Smaller enclosures tend to have lower poles.

Access to the lights on poles is essential for focusing.  Tip-over poles, favoured by maintenance engineers, are just not practical; the lights must be focused from their operating position.  ‘Cherry pickers’ were considered for Night Safari, but unless road or path access is very good, this is also impractical. Climbing rungs offered the best solution, and are installed on all poles.  The climbing crews have to be quite sturdy: repeatedly climbing 10 or so metres in the tropical night is hard slog.

This section has digressed into practical considerations, which is easy to do.  The Night Safari lighting cost several million dollars, most of which is buried, or black-painted steel.  Much of the practical working-out was done by the electrical engineer to the project, CY Tan, of Development Resources, a Singaporean firm of engineers.  His contribution was essential; a theatrical designer cannot possibly specify substations and electrical reticulation.  Good chemistry between engineer and designer will be of great benefit to any project of this sort.  Both disagreed on a lot in this project, and both learned a lot.

The development of an effective lighting design is an essentially creative process.  Many practical considerations have to be taken on board, and gaps in knowledge and experience have to be filled with field trials and experiments, but the quality of the lighting, and consequently the whole ‘night out’, will be determined by creative lighting design.