That makes perfect sense. Like an AC sucking up heat, taking it outside and converting it into light or rather anti dark matter.
Understood but what I'm saying is, that hasn't been my experience. I'm specifically running lamps with equal power input. Obviously a couple test runs aren't good proof but results are consistent so far. High CRI is performing beyond expectations.
specifically what "high CRI" lights are you comparing ? e.g. 3000K 80 cri vs 3000K 90 cri ?
Depending on the difference in photon output that could also be the case. In general high CRI would score higher on McCree RQE since it has more red and less blue. Which could offset or overcome a small difference in photons.
This would be true for most manufacturers. High CRI LEDs usually have too much far red to score any better.
Just got through doing 3000K 70 CRI vs 3500K 80CRI. In the past 90 CRI has beaten both 70 and 80 CRI. I'm currently finishing up a 3000K 90CRI grow. It's not a side by side and It's Vero 18g7 so it might not be the best GPW I've every had but it's looking like it will be the best GPPW I've ever had.
The photon difference between 3000K 70CRI and 3000K 90CRI is significant. Adjustment does favor the high CRI to a small degree but not nearly enough to offset the PAR reading.
McCree RQE curve is much wider though. I though something like 320nm to 780nm. YPF is calculated over 360-760. Wouldn't it skew the conversion factors if you're using only 400-700 and then especially for high CRI SPD's?
A small amount, but again not enough to alter the predictions. I would factor it in but the PAR meter drops off to almost zero at 700.
Measurements were taken with an Apogee SQ-520 and spectral response was corrected from 400-700.
It's a useful metric when it comes to efficacy of spectrums by energy output.
Using PAR watt is not about efficacy but about efficiency though.
Well Rahz had one done and the 90 CRI stretched out of the top of their box and then took twice the area to grow.
No disagreement there, but my own work has shown a pattern. If it's in error time should point it out.
I primarily use GPPW to determine the overall efficacy over various grows/mediums/lamps along with my skill in tending the plants. I don't know for sure but I suspect I'm bumping up against the plants limitations in this most recent grow. GPPW was higher at 60 g/sqft than at 73 g/sqft. That seems reasonable.
I just don't get why you use two metrics based on watts. Why not use the usual g/W and something that relates g to umol? The latter already corrects a lot for spectral differences where PAR W doesn't.
the rest of what's being "left-over" is converted to heat inside the leaf
