In my tests I liked the cmh/hps combined plants and bud the best. Nice full spectrum but with the power to penetrate better than cmh alone and even more red spike for best flowering. But with better leaf health and slightly faster flowering with some strains. Also a bit more compact.
Hps adds weight through depth where as cob/led add weight through width. Cmh used in multiple fixtures is a middle ground between the two but with a very good spectrum.
These are the key points to understand about hps/cmh/led as they can not be applied to 1 single dimention and expect linear results.
Take a 4x4 area for example. You could use a 1000W hps to cover it. Or, you could use a 315cmh in the middle (500W equive) and 2x200W cob units one either side. Cobs turn more W to light as do CMH so you are generating equal or more light to a 1000W hps yet only using 715W. However the penitration is not as good. If you are limited to that area it may effect weight.. but it also may not since you are getting way better coverage to the sides and corners but also remember you are using 300 less W.
Now here is the thing. If that area is expanded to a 6x6 the 1000W will lose effectiveness fast but the spread out fixtures of cmh/cob will still be able to cover it. This I beleive is where a lot of the hps advocates are going wrong. They are treating/comparing leds like hps grows when it's less than ideal to do so.
Cmh alone is fantastic for veg. But tends to grow too leafy and compact plants for our best crop.
Alone in my room the Hortilux super hps 600 I tested did approx. 30% better on yield and denser lowers than a 315 Phillips cmh every time.
I don’t lab test anymore but the patients could not tell which was more potent. I thought there was a difference pointing to cmh at first but I think the higher wattage hps grew more potent plants and the frost was equal. Confirmation bias may have taken a part here.
You can't compare a single 600hps to a single 315. The 600 out does it in W and light output. Compare it to 2xcmh where you will use the same W but get the effect of a 1000W bulb due to spectrum/efficiancy. The two cmh will not penitrate as far as a 600/1000W but you have two light sources.. so the outer edges of top canopy will be denser, making up for it.
This really highlights what I wrote above, people comparing hps depth alone to bash cmh/led (not you personally).. while making no mention or comprehention to the consistent across canopy density smaller multiple fixtures bring, on top of less risk of light/heat stress increasing top bud quality.
The university of Michigan is testing individual colored diodes and their effect on specific crops.
Mixed led with custom spectrums is still the future.
Current “”white” led chips were designed for natural lighting in retail showrooms and parking lots.
Just like mh and hps were street/ warehouse lighting at first.
Yeah don't get me wrong,I don't think any tech so far has the full packege as a stand alone tech. However, in most situations a mix of led/cmh is more efficiant use of watts if you lay it out correct. It will not get the same yield as hps if you treat it like hps, garunteed.