Without exhaustive analysis it's been impossible to tease apart the two most important constituents of lighting - lumens and spectrum. It's been a given in cannabis circles that more lumens deliver higher yields, and that watt-for-watt HPS delivers more lumens than any other lamp type. But until now no one has been able to say with confidence how much yield is a result of lumens and how much is a result of the spectrum. Furthermore, because little or no formal research is available for cannabis yields, many debates over spectrum often include references to plant species other than cannabis, thus not paying due respect to a crop (cannabis) that spends most of its time during flowering, the phase where its yield is produced and which is greatly influenced by spectrum. As you review Moon Doggie's final analysis you'll see how it was not only possible to separate these two important constituents of light, but to quantify each of them as well, using data collected from more than 150 indoor cannabis gardens.