Lighting Schemes: Different lighting schemes may be classified as, (i) Direct lighting scheme (ii) Indirect lighting scheme (iii) Semi-direct lighting scheme (iv) Semi-indirect lighting scheme (v) General diffusing scheme (i) Direct Lighting Scheme: It is the most commonly used type of lighting scheme. In this scheme, more than 90% of the total light flux is made to fall directly on the working plane with the help of a suitable deep reflector. It is most efficient but causes hard shadow and glare. The utilization factor of indirect lighting systems is about 40% to 60%. It is mainly used for industrial and general outdoor lighting. (ii) Indirect Lighting Scheme: When light is produced by fittings that throw all the light on the ceiling, from where it is reflected to the area to be lighted. In this system, more than 90% of the total light flux is thrown upward to the ceiling for diffuse reflection by using inverted or bowl reflectors. In such a system ceiling act as a light source, and the glare is reduced to a minimum. The resulting illumination in that system is softer and more diffuser, and less shadow prominent. The utilization factor in an indirect lighting system is about 10% to 35%. It is used for decoration purposes in cinemas, theaters, and hotels, and in workshops where large machines and other obstructions would cause troubleshoot shadow if direct lighting is applied. (iii) Semi-Direct Lighting Scheme: In this lighting scheme, 60 to 90% of total light flux is made to fall downwards directly with the help of semi-direct reflectors and the remaining light used to illuminate the ceiling and walls. This system is widely used for a room with having a high ceiling where a high level of uniformly distributed illumination is required. (iv) Semi-Indirect Lighting Scheme: In this lighting scheme, 60 to 90% of total light flux is thrown upward to the ceiling for diffuse reflection and the rest reach the working plane directly except for some absorption by the bowl. It mainly used for indoor lighting decoration purposes. (v) General Diffusing Scheme: In this system, luminaries are employed which have almost equal light distribution downwards and upwards. General Classification of Luminaries: [ alt="F1 Harish Batula 13.5.21 Pallavi D6" src="//storage.googleapis.com/tb-img/production/21/05/F1_Harish%20Batula_13.5.21_Pallavi_D6.png" style="width: 569px; height: 288px;">