Book excerpt: 'Lighting Engineering: Applied Calculations' describes the mathematical background to the calculation techniques used in lighting engineering and links them to the applications with which they are used. The fundamentals of flux and illuminance, colour, measurement and optical design are covered in detail. There are detailed discussions of specific applications, including interior lighting, road lighting, tunnel lighting, floodlighting and emergency lighting. The authors have used their years of experience to provide guidance for common mistakes and useful techniques including worked examples and case studies. The last decade has seen the universal application of personal computers to lighting engineering on a day-to-day basis. Many calculations that were previously impracticable are therefore now easily accessible to any engineer or designer who has access to an appropriate computer program. However, a grasp of the underlying calculation principles is still necessary in order to utilise these technologies to the full. Written by two of the leading authorities on this subject, 'Lighting Engineering' is essential reading for practising lighting engineers, designers and architects, and students in the field of lighting.