Popularly referred to as energy-saving lamps, compact fluorescent lamps have a poor image because of perceived deficiencies in colour, power and speed to full output. But massive improvements have been made in all these areas thanks to substantial investment by the big lamp manufacturers.
The UGR method (Unified Glare Rating) is an international index presented by CIE, the international lighting research body, in its publication 117 and is used to evaluate and limit the psychological direct glare from luminaires. Contrary to previous methods where the glare was rated using the luminance values of a single luminaire, this method calculates the glare of the entire lighting installation at a defined observer position.
Ceramic metal halide (CMH) lamps combine high output with great colour rendering and good efficiency. They produce light by passing an electric arc through a mixture of gases. In a metal halide lamp, the compact arc tube contains a high-pressure mixture of argon, mercury, and a variety of metal halides.