Lighting an indoor is relatively challenging as there is a lack of information and standardisation on the level of lighting required for indoor riding. Everyone is fairly much agreed that hard shadows are to be avoided, the lighting should be even and that show jumping requires more lighting than flat work.

A UK company called Jumping Jack Flash (http://www.jumpingjackflash.co.uk/) had some suggestions on its web site which can be summarised as:

For indoor arenas
  • Show Jumping - 400 lux
  • Dressage - Training - 300 lux
  • Dressage - Competition - 500 lux
For outdoor arenas
  • Show Jumping -Training - 150 lux
  • Show Jumping - Competition - 300 lux
  • Dressage - Training - 100 lux
  • Dressage - Competition - 200 lux
all with uniformity ratio of 0.5 and measured horizontal to the ground (See http://www.jumpingjackflash.co.uk/levels.html for the original document).

We eventually bought a light meter and visited a few indoors we deemed to have good lighting and measured the maximum and minimum light levels at 1m above floor level as we crossed the arena. After combining our measurements with the information we collected we contacted the importer of the lights we wanted to use and they designed the positioning of the lights in terms of number and placement to achieve the required light levels.

The designer needed to know:
  • the required light level at 1m above the ground
  • the lighting technology eg Metal Halide or Fluorescent
  • the ceiling height and attachment mechanism
  • the materials and locations of walls next to the lit area

Our illumination level varies between 235 and 431 Lux the specification read “300 lux with a uniformity ratio of 0.5”

We ended up using 400W Metal Halide lamps with reflectors attached via chain to metal strapping going around the ceiling beams. The chain mount has the advantage of allowing you to set the height above ground precisely across the arena to give a more even light, however, they will sway if the main door of the arena is open and there is a strong breeze. Only 15 lights where required for the installation which reduces maintenance effort. To achieve a similar illumination with fluorescent lights would have taken over 100 tubes. Metal Halide lamps have a very high starting current that then reduces to its normal operating current. Your electrician will need to make sure that both the wiring and the supply is sufficient for the starting current.

We believe the uniformity ratio is calculated as follows:

the minimum light level / average light level