feedtheworld

I am new to this forum and was wondering if there are any veteran growers or hobbyists out there that can give me some technical advice on a low power lighting array I wish to build. I want to know what specific wavelengths of light are the most efficient in terms of watt -> effective photosynthesis. I have thumbed through several websites, and most have general lumen to square footage quotes. Which is fine for flourescents or common light sources, but if I can purchase LED bulbs on specific wavelengths I would like to know how much light (in those specific wavelengths) would be the most efficient per square foot of plant surface. I have seen a few PAR graphs, and it looks like somewhere between 650 nm - 700nm (for red) and 450 nm - 470 nm (blue). I also understand that blue is not needed as much as red and that the lower the nm the less power is needed to create equivalent brightness. But I am not sure as to what the blue to red ratio would be.