I have no idea wht yiu are g bring Lumens into the conversation oftther than my bringing up th a 7500The charts K halide bulb. I was off on that anyway as it is the Iwaki 6500K that provides the better lighting. While yed s it does waste some light by providing more than need proportionally in the 500 to 550 range, overall it provides lighting fitting the response cure better than the other halides or the HPS. The response curve chart reflects the needs rfor amonyts of lightneeded in the different wave lengths by plants. The response curve chart reference a plants positive response in those wavelengths. It references how plants responds to lights in specific ranges required for growth. The halide shown even shows the halide dips in the small area where the response curve dips. Saying light output is a waste in that rae is ludicrous as it is a small dip in that area is ludicrous as it is not a drop to zero. Most LED systems are almost totally lacking in out put in that area. ie deficient. I have no idea what you are even trying to say in your last sentence as HPS puts out very little light in the 450 nm range so saying it absorbs most is a bit off as it should absorb more and be begging for more. HPS is deficient between 400 and 550 nm period. I have no idea why your talking lumens or CRI. The charts clearly show that halide in general covers the needs of plants over the full response curve better than the HPS. HPS provides a bit more light in the 550 to 650 nm range than the ahlide but is deficient in comaparison to the halide from 400 to 550 nm.
While yes if LED's were developed that supplied enough intensity the would be good plant lights that is not yet the case. Unless they are used for short grows like fast SOG grows from clones they really do not have much value. Even then it takes very expensive high output LED's to even provide enough lighting for SOG's, yet alone something like 18" plants. Forget about 24" or more.
I'll stick with mixed halide and HPS or primarily halide with HPS supplementation.
