Plainsman,
Tazawa implies that quality light matches the photosynthetic action spectrum (PAS). To get “perfect” light then we’d need to match luminant flux at every wavelength. Due to the ability of mixing phosphors, fluorescents are better than any other discharge lamps at matching PAS, if you pack them so they touch you can get about 50klux. But 1sq meter would require ~30 bulbs. So forget flo’s.
I was unable to find the saturation point of MJ so I’m guessing it’s 50klux. Since I couldn’t find enough valid data to make integrating spectra worth while, I printed and measured the emission spectra of several HID sources at 10nm intervals; HPS, MH, cool-MH, warm-MH, warm-HPS. I fit a 6th order curve to the PAS and multiplied it by the normalized spectra then summed the results. This gave me a measure of “quality”; perfection has a value of 1.00. Tazawa also indicated that plant stretching was induced by high (red/blue) ratios, and low (red/far red) ratios. The PAS has a r/b of 1.9 and r/fr of 6.6.
Quality; r/b; r/fr
HPS = 0.70; 3.1; 4.8
MH = 0.64; 1.5; 9.1
cMH = 0.61; 0.7; 6.6
wMH = 0.69; 2.0; 15.3
wHPS = 0.72; 5.6; 5.1
I suppose you could solve the equations for three parameters simultaneously using all five lamps but, yikes, I don’t want to use a combination of all five lamps, so I solved @r/b=1.9 using only two types at a time. This gave me all the r/b=1.9, combinations. All resulting qualities were between 0.65 and 0.67, not much difference, so I chose the combo that gave the r/fr closest to 6.6. This was 2.0 lum MH per l.0 lum HPS yielding r/fr=7. (NOTE: 2.6 was a calculation error).
Oh, you said brief, sorry.
1sq-ft per plant, I was thinking 3sf/plant! Oh yea, good luck with the Tazawa reports!