for same power why different suppliers with different brightness

Time：2015-01-12　Hits：2250　Compile：SUNPER

Question: For same power,why different suppliers with different brightness?

Answer: 

Please make clear the LEDs brightness ≠ lamp fixture total brightness.

Some suppliers use Bridgelux, and some suppliers use Cree for LED high bay light, LEDs efficiency is diffierent between Bridgelux and Cree. Cree has a higher brightness than Bridgelux.

For example,100W LED high bay light,Cree chips during 120-130lm/w,the LEDs brightness will be 12000-13000lm. But the hole led high bay light luminous will be only around 10000lm.