What is a goniophotometer, and why is it important for LED streetlights?
The optical power of a light source would be an important factor to consider. In most cases, an EEI tester is used for this criteria, and lumens or watts are used to express the data (watt). However, this method ignores the spatial distribution of brightness. Because of this, a goniophotometer might be used as an alternative measurement method. Although goniophotometers are more labour-intensive than integrating spheres, they provide far more accurate readings. It is also the technique of choice for measuring bulbs with varying luminous intensity distributions. Compared to an integrating sphere, a goniophotometer stands out due to its ability to quantify partial luminous flux and the angle of half intensity. Near-Field Vs Far-Field It is possible to consider the source as a point when LEDs are assembled in certain situations. There are further contexts when the source has to be understood as an expanded source. This would imply that the source's light output varies spatially