Ray, I appreciate your assertion that "light is light." But if that is so, then why all the rigamarole about micromoles and PAR meters and 'oh no, you can't trust your eye for the light your orchids are receiving from LEDs.' (I have yet to read a comment on the fact that PAR and human sensitivity to light are roughly equivalent). Diversionary tactics? For practical purposes, different sources of light behave differently. Isn't that all we're interested in? Those of us who are scrambling for a light source to replace the sunlight that we don't have? How a given source of light behaves? HID opposed to fluorescent, as opposed to LED? Isn't this what everyone is trying to figure out? And there are real, practical differences. Depending on the fashion, everyone touts the drawbacks of one and the strong points of the other. But who is saying, impassionately, what each ones does, and doesn't do? Why, at this point, isn't there a "Bible" for growing under artificial light? Maybe there is and I've just missed it.

So, what I've noticed, given my reasonably competent on-the-fly setup, is the spike on my Phal. schilleriana. There is a huge amount of difference between the buds on the lower part of the spike and the upper part of the spike, and it's a short spike - the first to bloom on this plant. It all fits under my light set-up. The spike will not elongate at the terminus because the nature of schilleriana is that buds develop and bloom simultaneously. I could be wrong, but I don't think this would have happened with HID light, whatever one might say about wasted energy in heat. I appreciate the learning that can compute light fall-off, but the thing about HID light is that there is more flexibility as to placement and natural blooming. With LEDs, this doesn't seem to be the case. Why is that? Oh, I think I just answered my own question. You'll forgive the process I have to go through. And maybe you will even confirm it. With HID, there is more energy that evens out light "scattering." So, the range of useful light is widened and more generalized (and would yield a more natural blooming on tall spikes, for example). With LEDs, the angle of useful light is more focused and the energy is reduced to produce that more narrow angle of useful light, but in which the intensity escalates or de-escalates rapidly. So it would be difficult if not impossible to replicate the generalized coverage of HID light with LED light because the focus of LED light is comparatively narrow. I don't know. Am I on the right track? If so, some "wasted" heat energy would seem worthwhile for more natural blooming. Assuming it is affordable for a given grower.