Photobiologically Active Radiation (PBAR) is a range of light energy beyond and including PAR. Defining the specific range for PBAR is difficult as there are discrepancies of which nanometers the range should include. Some use 300-800nm while others use 350-800nm or 280-800nm. It is important to pay attention to the range used for data presented until a specified range is widely adopted.


Photobiological Photon Flux (PBF) is the metric used to measure PBAR. It is a total count of light energy (in photons) inside the PBAR range. The PBF measurement is a better metric than PPF to describe the power of a light source for growing as it includes UV and far-red energy.