Found this on the net -
https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator
EB2 has 80 CRI which is considered as low? According to this guide -
https://www.flexfireleds.com/color-rendering-index-cri-and-led-lighting-what-is-cri/,,,
"- Lights with a CRI that is measured greater than 80 are considered to be more than acceptable for most applications.
- Lights with a CRI that is measured greater than 90 is generally considered “High CRI” lights.".
So,,,, if i load 40000 lux and "low cri led 3500k" in the calculator in the first link i'll get
641.48 umol/s/m2.
But if i take 641,48*71 i get 45545?
CRI80 and 90 have different efficiency and when you measure lux and set both to the same wattage you would get more lux from CRI80 cause lux meters are made for human eyes and have a green filter integrated to favor green(brightest for the human eye).
CRI90 has a higher QER(~5} like CRI80(~4,8 ) which means a better, more efficient spectrum for CRI90. But CRI80 has higher LER which means its more efficient in converting energy into light.
In the end 40klx CRI90 are more useful for plants like 40klx CRI80, yes, but you need ~10% more energy to create 40klx in CRI90.
The waveform calculator is made to favor their own products. It's not really useful to compare CRI 80 and 90 just based on lux without mentioning the used wattage.
Visit
https://www.led-tech.de/de/system-light they have a nice spectrum calculator for Samsung LM301b boards and strips and additional Osram Oslon/Square strips you can add to the list. You can add more or less diodes, you can chose different drive currents and it calculates watts used, μMol/J, μMol/s PPF, CRI and lumen output.
You want CRI90 but more efficient like CRI80 and far better than CRI90 efficiency?
Take the brightest and most efficient 4k/CRI80 diodes for instance Samsung LM301H and add 15-20% of the best available deep-red diodes on a separate boost circuit. CRI shifts to CRI89-91 and because of the added deepreds the spectrum shifts to ~3500°k. Deep-red's are the most powerful diodes and they produce the most usable photons. Blue is more elect. efficient but blue photon carry twice as much energy therefor red diodes have twice as much photons per watt.
So with adding deep-red you can make your base light more efficient.
If the budget does not matter you could even achieve an efficiency of up to 3.0μmol/J, system efficiency still ~2,8! HPS has 1,3-1,4, CMH creates up to 1,9μMol/J. Sammys new horti strips create 2,74μMol/j, system efficiency probably still 2,55.
You can already get commercial fixtures reaching 2,7μMol/j. Amare's bar8 or fluence spider2i for instance. Not cheap but they demonstrate how efficient the strip design is when it comes to plant lighting. Shortest distance paired with unbeatable uniformity and penetration leads to less light loss and highest system efficiency.