Candela (cd) is the unit of luminous intensity.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Candela is the amount of light a light source emits in a particular direction. The amount of candela is subject to the opening angle of a light source. The distance from the light source has no influence on the amount of candela. On a distance of 1 meter, the amount of candela of a light source is equal to the candela on a distance of 2 meters. The surface area does become bigger because of the expanding angle.

 

The distance from the light source has no influence on the amount of Candela.

 

The opening angle (wide/small light beam) does have an impact on the amount of candela. Let's say you have a light source of 300 lumen. If this light source of 300 lm is being bundled into an opening angle of 10°, the amount of candela will be bigger than when the light source radiates in an angle of 50°. In the latter case the light has to be spread over a larger opening angle. Candela is the amount of light (lumen) per steradian. 

 

The opening angle of the light source does have an influence on the amount of Candela.