Light quantity refers to the intensity or concentration of light.

Light Quality
Light quality refers to the color or wavelength of light.
Remember the acronym ROY G. BIV (from grade school) relating to the colors of the rainbow?
This acronym refers to how a prism breaks light into their respective colors of Red, Orange, Yellow, Green, Blue, Indigo, and Violet.


Light Duration
Light duration (or photoperiod) refers to the amount of time that a plant is exposed to sunlight.
The ability for plants to bud or flower is controlled by the photoperiod.
In reality, it is not the length of the light period (photoperiod) but the length of uninterrupted dark period that is the critical key element to budding and floral development.

Spectral Properties of Light & Plants
There are certain basic principles of the interaction of light and matter when light measurements are being discussed.
The physical properties of the light and its biological effects depend strongly on wavelength.
The energy balance of a leaf is strongly influenced by its spectral absorbance.
Pigment absorption is largely confined to the 300-700 nm regions

Photometric
Light measurement expressed in terms of perceived brightness to the human eye
(expressed in lumens)

Radiometric
Light measurement expressed in terms of absolute power
(expressed in micromoles)

Traditional grow lighting is generally measured by the amount of Photometric Energy produced (expressed in lumens)

Chameleon™ Solar Genesis™ Grow Lighting is measured by the amount of Radiometric Energy produced (expressed in micromoles)