Manufacturer provided specifications for brightness can be misleading because they are not all measured in the same way. Stock reflectors are designed to maximize brightness and make lights seem more powerful than they may be in real-world use.
The data in this table was measured without any reflectors or modifiers, which is the best way to accurately compare lights.
Lux: A common measurement of light brightness equal to one lumen per square meter (measured at a standard 1m distance)
F-Stop: The f-stop required to achieve proper exposure at 18% gray (measured at a standard 1m distance at ISO 100 and 1/50 second shutter speed, the most common settings for video)