Explain different types of Lighting schemes or Illumination schemes.

Direct Lighting Scheme:

In direct lighting scheme, more than 90% of the light falls on the object to be illuminated. Only 10%
of the light goes in the upper hemisphere. Generally in this case the source of light is mounted on
the reflector. (Such as plastic) This type of lighting scheme is employed in residential lighting,
industries and commercial lighting. Continuously working under direct lighting scheme will cause
strain on the eyes.

 

Semi-direct Lighting Scheme:

 

In this lighting scheme, about 50% of the total light is allowed to fall directly on the object to be illuminated and about 30% is sent upward. It provides an uniform distribution of the light and avoids glare.

 

Indirect Lighting Scheme:

 In this scheme, light does not fall on the objects directly. Maximum light is thrown upwards (towards ceiling) and then it is diverted towards the object to be illuminated. This type of scheme is employed for drawing offices and workshops where shadows are to be illuminated. In this scheme there is additional requirement of light about 50 to 100%.

 

Semi-indirect Lighting Scheme:

 In this scheme about 60% to 90% of light is projected upwards and about 40 to 10% of light is allowed to fall directly on the object to be illuminated.This type of lighting scheme is employed for decorative purpose.

 

 General Lighting Scheme:

 In this scheme, lamps are made up of diffusing glass which gives equal illumination in all directions. This system in fact is ideal system.