How do we define a good lighting scheme? Central to the integrity of any Equation scheme are the following eight 'commandments' developed by the German Architect, Dr. R. Kramer:

• Lighting should show people in space & time.
  
• Lighting should be an integral part of any scheme.
  
• Lighting should be conceived as a whole, within such a scheme.
  
• Lighting should show mood and atmosphere appropriate to function.
  
• Lighting should convey a message beyond illumination.
  
• Lighting should be original and not mass-produced or a reproduction.
  
• Lighting should permit and provoke communication between people.
  
• Lighting should encourage us to celebrate our environment.