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Give a man a salad...

Agreed.

You are referring to a vast majority of the grow industry. Most people outside of this forum have never heard the term COB before and think of disco lights as led grow lights. COB's are: Superior technology.. Absolutely In mainstream press... Not so much. When COB fixtures are advertised in...

I think everybody needs to give this a good read through... https://en.wikipedia.org/wiki/Reflection_(physics)

I find PAR readings to be especially useful when we already know the spectral distribution of the light being emitted. If we know what the SPD looks like, we can make comparisons using relative intensity. IME, if two light sources have the same output/intensity, the light with the fuller...

Different watt consumption yes.. But if you calculate PAR/Watts, the SK has an average of 27.82 PAR/Watt @ 24" (based on my measurements) compared to the LEC which has an average of 22.29 PAR/Watt @ 24". I think they just wanted everybody to believe that they were somehow lightyears ahead of...

BTW, I don't really support Spectrum King as a company or agree with how they practice business. But the product ain't bad... :EDIT: I will also say SK recommends their product hang 18"-24" above the canopy. I have the 18" data as well.. If anybody was interested in seeing that then let me...

Yes, actually I myself have tested these two lights head to head with a PAR meter. I work at a grow store and we have both the SK400+ 90 deg. and a Sun Systems LEC 315 hanging on display. The light performs just as the company claims. It's a great product compared to most other big name...

Albeit more expensive upfront, the SK400+ outperforms LEC/CMH/CDM per PAR Watt, and overall has quite a bit more output than the Philip's 315 bulbs. The Spectrum is also much fuller and tailored for flowering plants.

Thanks a lot! :joint:

You mean cone shaped plastic does not emit light all on its own?? Man, I thought I was just getting the hang of this stuff...

Or add reflectors/lenses and gain 20-30% higher ppfd over desired area...

This is how I determined COB spacing, and whether reflectors would be necessary. This data is courtesy of @robincnn . Sorry I didn't ask permission first.

@wietefras I understand just fine, thanks. I agree, that depending on the size of the grow space, not using reflectors or lenses would actually only make sense. Small spaces/ cabinets would more than likely not need any optics and would often times have reflective walls because of the nature...

@wietefras Wow, never mind.

Specifically for testing I did not use reflective walls. Once spacing was achieved (one COB every ft2), I measured at distance with reflectors and without. The difference in output was close to 30% greater w/reflectors but sadly I didn't record any of this testing. Just the finished product...

I'm not sure we can deduce those conclusions based on several week old immature plants. I think some trials with mature fruiting plants are in order before we can ascertain those findings.

^^^ yup.

I have tested this. Reflectors and/or lenses create much more usable light at depth (penetration) than a bare COB without any optics (proper spacing). The difference is pretty significant. COB's throw light damn near 180 deg. in all direction and even reflective walls don't redirect enough of...

Are you talking watt for watt, or matched PPF output? Running at 60% or higher efficiency is expensive up front, but depending on the scale of the grow, the ROI could be made back much quicker than you seem to think just from power consumption. Even at 56ish% ([email protected]) the difference in actual...