Lighting Spectral Data

[Northern_Loki]

Overgrow Independently Measured Lamp Spectra

Methods and descriptions

Measurement device:

Stellarnet CXR-SR-100 w/ CR2 Cosine Adapter.
The measurements in this thread are single point, 18 inches from the center of the light source. This is for consistency and is the most relevant metric for verifying/comparing against manufacturer specifications. It is a direct measurement. This thread is namely to capture the spectrum distribution for various lamps which will be consistent over the illuminated area. The total power will vary depending on the distance to the source, the spread of the lamp / optics, the size/nature/reflectivity of the room, and the cosine angle to lamp while the spectrum will remain consistent.
With that noted, an important metric when designing your room for lighting is PPFD. This is the intensity measured and averaged at various intervals over a defined area. The spread of the light output over an area defines the useful working photons. Where inclined, PPFD and/or PAR maps are measured using an Apogee PAR sensor noting the caveat that the room itself will have an impact on the actual PAR maps due to reflection (e.g. measurements are partially indirect).
As an example, in some cases the measured power (W) appears much greater than expected. This is because the measurements using the spectrometer is based on the illumination of a square meter. These measurements are spot measurements at the center of the lamp. We calculate the power assuming the square meter is evenly illuminated. In reality, the square meter is not evenly illuminated, the power would decrease as we move away from the center, and the total power across that square meter would significantly less. A focused spot like lamp would indicate greater power output as compared to a diffuse / spread-out lamp even if the two lamps produced the same PPF. So, keep this in mind when reading through this information. PPFD, the type of room, etc is equally important.

Definitions:

PAR - range of photosynthetically active radiation. Unless noted otherwise, typically 400-700nm. This is the most common range utilized when describing horticultural lighting although there are wavelengths outside of this range that are also sometimes considered. If so, the wavelength should be defined. It is common to see PAR used interchangeable with PPF as a metric of power over 400-700nm.
PPF - Integral power across the PAR range of wavelengths.
SPD - Spectral power distribution. Absolute photon flux as measured across the spectra. A spectrometer will measure photon flux in discrete “bins” of frequencies. From these “bins”, one can calculate the total power across the spectrum or power within a narrow band of frequencies. (e.g. power in the blue spectrum). The spectral graphs generated from a calibrated spectrometer details SPD. An uncalibrated spectrometer generates spectrum distribution but would not contain accurate power information (just relative power).
YPF - yield photon flux. Weighted photosynthetic yield measurement across 360 to 760nm.
YPF/PPF - the ratio between the PAR and YPF calculations. This metric exposes how closely the overall light output in the PAR region targets the traditional quantum efficiency curves. The closer this is to one, the closer of a match. This metric is bit of an oddball. Matching an efficiency curve with the intensity output makes some sense in that your targeting more efficient conversion but such matching doesn’t necessarily address what ratios the plant actually needs under various circumstances. However, it appears that this metric is utilized by some OEMs to design their spectra and they have been relatively successful. Adding more green, for instance, will show a decrease in this ratio.
PPE or PSS - estimated phytochrome photoequilibrium. Also termed PSS. Ratio of Pfr to Pr. Pfr : ( Pfr + Pr ) where Pr is the photon flux integral across 600-700 nm waveband. Pfr is the integral across the 700-800 nm waveband. This acronym is also used when describing lamp efficiency. Try not confuse that in this context.
PPE - Photosynthetic photon efficacy. This is another definition of PPE. It is a relative ratio of the input power that is converted to usable photons. The higher the number, the higher the efficiency of the lamp.
DLI index : the integrated amount of PAR light your crop would see over the period of a 12 hour day under the test conditions.

Notes:

PAR (PFD) can be misleading if you are not paying attention. The standard for PAR is between 400 and 700nm. For non-traditonal “McCree” spectra, the PAR measurement may not capture the majority of the power. For example, UV and far-red will fall outside of the PAR spectrum though there are good reasons to consider implementing a lighting strategy that includes these spectra. YPF has a broader range but is weighted (by committee) depending on the photosynthetic action spectra. While this might be valid, it can be confusing if you are looking for raw irradiance values that are not weighted. The integral radiance numbers are the raw radiant power measured and can be converted to umols by using an estimated conversion factor such as 4.2 or by converting each wavelength bin to equivalent photons (mols) and then integrating over your desired range.

P.S. the coloring of the following graphs is artificial. The actual colors may not perfectly line up with what would be perceived but is instead simply meant as a guide to the general color red/blue/green/etc.

P.P.S sometimes I forget to relabel the graph titles, so please ignore it if it doesn’t match what you’d expect.

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Heliospectra

Heliospectra 601G

(All spectrum set at 100%, open air, single point, 18" distance from center of lamp):

Integral radiant (400-700nm): 197.9 W/m^2
Integral radiant (350-840nm): 201.9 W/m^2 
PAR (400-700nm): 993.6 umol / m^2 s
YPF (360-760nm) : 887.6 umol / m^2 s
YPF/PFD: 0.89
PSS: 0.87
DLI index [12 hours] : 42.9

400-500nm Blue : 15.50%
500-600nm Green : 11.57%
600-700nm Red : 72.93%

287-320nm UVB : 0.01%
320-399nm UVA : 0.10%
400-475nm Violet-Blue : 14.08%
476-550nm Cyan-Green : 6.12%
551-700nm Green-Yellow-Red : 77.47%
701-850nm Far Red-NearIR : 2.23%

Power consumption: 512.82W

---

Heliospectra 601C

(All spectrum set at 100%, open air, single point, 18" distance from center of lamp):

Integral radiant (400-700nm): 154.9 W/m^2 
Integral radiant (350-840nm): 177.6 W/m^2 
PAR (400-700nm): 759.7 umol / m^2 s 
YPF (360-760nm) : 693.5 umol / m^2 s
YPF/PFD: 0.91
PSS: 0.82
DLI index [12 hours] : 32.8

400-500nm Blue : 19.90%
500-600nm Green : 13.52%
600-700nm Red : 66.58%

287-320nm UVB : 0.01%
320-399nm UVA : 0.12%
400-475nm Violet-Blue : 15.61%
476-550nm Cyan-Green : 6.27%
551-700nm Green-Yellow-Red : 62.74%
701-850nm Far Red-NearIR : 15.25%

Power consumption: 473.28W

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Fluence Bioengineering

Fluence RAY44 PfrSpec

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 1.2 W/m^2
Integral radiant (700-800nm): 22.3 W/m^2 
PAR (400-700nm): 7.06 umol / m^2 s
YPF (360-760nm) : 24.32 umol / m^2 s
YPF/PFD: 3.44
PSS: 0.14
DLI index [12 hours] : 0.3

400-500nm Blue : 0.45%
500-600nm Green : 0.64%
600-700nm Red : 98.91%

287-320nm UVB : 0.01%
320-399nm UVA : 0.01%
400-475nm Violet-Blue : 0.02%
476-550nm Cyan-Green : 0.02%
551-700nm Green-Yellow-Red : 5.52%
701-850nm Far Red-NearIR : 94.42%

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Fluence RAY44 UVSpec

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 28.5 W/m^2
Integral radiant (350-840nm): 34.1 W/m^2 
PAR (400-700nm): 97.53 umol / m^2 s
YPF (360-760nm) : 81.82 umol / m^2 s
YPF/PFD: 0.84
PSS: 0.55
DLI index [12 hours] : 4.2

400-500nm Blue : 99.99%
500-600nm Green : 0.01%
600-700nm Red : 0.00%

287-320nm UVB : 0.02%
320-399nm UVA : 19.07%
400-475nm Violet-Blue : 80.89%
476-550nm Cyan-Green : 0.01%
551-700nm Green-Yellow-Red : 0.00%
701-850nm Far Red-NearIR : 0.00%

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Vyprx Plus Greenhouse Spectrum

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 215.5 W/m^2
Integral radiant (350-840nm): 221.9 W/m^2 
PAR (400-700nm): 997.1 umol / m^2 s
YPF (360-760nm) : 867.6 umol / m^2 s
YPF/PFD: 0.87
PSS: 0.85
DLI index [12 hours] : 43.1

400-500nm Blue : 23.71%
500-600nm Green : 40.52%
600-700nm Red : 35.76%

287-320nm UVB : 0.01%
320-399nm UVA : 0.16%
400-475nm Violet-Blue : 17.77%
476-550nm Cyan-Green : 21.82%
551-700nm Green-Yellow-Red : 56.66
701-850nm Far Red-NearIR : 3.58%

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Spydr 2P PhysioSpec Indoor

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 186.4 W/m^2 
Integral radiant (350-840nm): 192.3 W/m^2 
Lumens (m^2) : 54821
Spectrometer PFD (400-700nm): 889.56 umol / m^2 / s 
Spectrometer PFD (350-840nm): 925.5 umol / m^2 / s 
Quantum Sensor PFD (400-700nm): 850.4 umol / m^2 / s
YPF (360-760nm) : 791.86 umol / m^2 / s
YPF/PFD: 0.89
PSS: 0.86
DLI index [12 hours] : 38.4

Blue(400 - 500nm): 16.24%
Green(500 - 600nm): 38.14%
Red(600 - 700nm): 45.62%

UVB(287-320nm): 0.01%
UVA(320-400nm): 0.12%
Violet_Blue(400-475nm): 11.91%
Cyan_Green(475-550nm): 18.58%
Green_Yellow_Red(550-700nm): 65.56%
FarRed_NearIR(700-850nm): 3.82%

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Mars Hydro

MH-SP-250

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 100.6 W/m^2
Integral radiant (350-840nm): 104.5 W/m^2 
Lumens (m^2) : 32794.83
Spectrometer PAR (400-700nm): 475.58 umol / m^2 s 
Quantum Sensor PAR : 451.6 umol / m^2 s
YPF (360-760nm) : 424.57 umol / m^2 s
YPF/PFD: 0.89
PSS: 0.85
DLI index [12 hours] : 20.5

400-500nm Blue : 15.98%
500-600nm Green : 43.90%
600-700nm Red : 40.11%

287-320nm UVB : 0.01%
320-399nm UVA : 0.17%
400-475nm Violet-Blue : 13.42%
476-550nm Cyan-Green : 17.65%
551-700nm Green-Yellow-Red : 64.04%
701-850nm Far Red-NearIR : 4.71%

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Vivosun

VS4300

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 179.9 W/m^2
Integral radiant (350-840nm): 183.0 W/m^2 
Lumens (m^2) : 54821 
Spectrometer PFD (400-700nm): 837.75 umol / m^2 / s 
Spectrometer PFD (350-840nm): 856.39  umol / m^2 / s 
Quantum Sensor PFD  (400-700nm): 844.7 umol / m^2 / s
YPF (360-760nm) : 728.5 umol / m^2 / s
YPF/PFD: 0.87
PSS: 0.85 
DLI index [12 hours] PAR : 36.2 

400-500nm Blue : 21.31%
500-600nm Green : 42.32%
600-700nm Red : 36.37%

287-320nm UVB : 0.01%
320-399nm UVA : 0.13%
400-475nm Violet-Blue : 15.21%
476-550nm Cyan-Green : 22.69%
551-700nm Green-Yellow-Red : 59.78%
701-850nm Far Red-NearIR : 2.19%

---

Unbranded

E27 10W Ultra Bright UV Ultraviolet Color Purple Light 160LED Lamp Bulb 110v

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 6.85 W/m^2
Integral radiant (350-1100nm): 10.70 W/m^2 
PAR (400-700nm): 
YPF (360-760nm) : 
YPF/PFD: 
PSS: 
DLI index [12 hours] : 

400-500nm Blue : 97.73%
500-600nm Green : 1.07%
600-700nm Red : 1.20%

287-320nm UVB : 0.03%
320-399nm UVA : 34.28%
400-475nm Violet-Blue : 60.47%
476-550nm Cyan-Green : 0.63%
551-700nm Green-Yellow-Red : 1.10%
701-850nm Far Red-NearIR : 3.49%

---

5W E27 UV Ultraviolet Purple LED Spotlight Bulb Home Lamp Light AC 85-265V

(open air, single point, 18" distance from center of lamp)

Integral radiant (400-700nm): 18.29 W/m^2
Integral radiant (350-1100nm): 25.99 W/m^2 
PAR (400-700nm): 
YPF (360-760nm) : 
YPF/PFD: 
PSS: 
DLI index [12 hours] : 

400-500nm Blue : 99.50%
500-600nm Green : 0.38%
600-700nm Red : 0.12%

287-320nm UVB : 0.01%
320-399nm UVA : 31.99%
400-475nm Violet-Blue : 67.44%
476-550nm Cyan-Green : 0.23%
551-700nm Green-Yellow-Red : 0.21%
701-850nm Far Red-NearIR : 0.12%

Note: As discussed earlier, while the measured power (W) appears much greater than the specified power, notice that the measurement is based on the illumination of a square meter. The measurements for spectrum are spot measurements at the center of the lamp and we calculate the power assuming the square meter is evenly illuminated. In reality, the square meter is not evenly illuminated and the total power across that area would be much less. A focused spot like lamp will indicate greater power output as compared to a diffuse / spread-out lamp.

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Comparative Spectras

Inside of a greenhouse natural light filtered by glass glazing + supplemental:

Integral radiant (400-700nm): 252 W/m^2
Integral radiant (350-840nm): 297 W/m^2 
PAR (400-700nm): 1042 / m^2 s
YPF (360-760nm) : 919 / m^2 s
PSS: 0.76
DLI index [12 hours] : 

400-500nm Blue : %
500-600nm Green : %
600-700nm Red : %

287-320nm UVB : %
320-399nm UVA : %
400-475nm Violet-Blue : %
476-550nm Cyan-Green : %
551-700nm Green-Yellow-Red : %
701-850nm Far Red-NearIR : %

---

Sunlight, 11AM EST Northeast US. Current conditions partially cloudy.

Integral radiant (400-700nm): 341.7 W/m^2 
Integral radiant (350-840nm): 483.8 W/m^2 
PAR (400-700nm): 1580 umol / m^2 s
YPF (360-760nm) : 1412 umol / m^2 s
YPF/PFD: 0.89
PSS: 0.72
DLI index [12 hours] : 68.3

400-500nm Blue : 25.49%
500-600nm Green : 35.45%
600-700nm Red : 39.05%

287-320nm UVB : 0.06%
320-399nm UVA : 3.06%
400-475nm Violet-Blue : 11.54%
476-550nm Cyan-Green : 16.07%
551-700nm Green-Yellow-Red : 37.17%
701-850nm Far Red-NearIR : 32.09%

Power consumption: Free!

---

Sunlight Tree Shaded, 11AM EST Northeast US. Current conditions partially cloudy.

Integral radiant (400-700nm): 39.7 W/m^2 
Integral radiant (350-840nm): 60 W/m^2 
PAR (400-700nm): 173.9 umol / m^2 s
YPF (360-760nm) : 154.2 umol / m^2 s
YPF/PFD: 0.89
PSS: 0.67
DLI index [12 hours] : 7.5

400-500nm Blue : 38.67%
500-600nm Green : 35.22%
600-700nm Red : 26.12%

287-320nm UVB : 0.20%
320-399nm UVA : 7.39%
400-475nm Violet-Blue : 17.19%
476-550nm Cyan-Green : 16.93%
551-700nm Green-Yellow-Red : 25.35%
701-850nm Far Red-NearIR : 32.95%

Power consumption: Free!

[Hoodini]

For those of us (maybe just me) but what the hell does that mean? It’s just 2 cool looking rainbow wave pictures with numbers and letters to me hahahaha does it mean that the light is good?

[Northern_Loki]

LOL.

For reference/point of comparison, for those looking at the spectral balance and irradiance (amount of light illuminating a plane). And/or are interested in comparing actual measurements to the OEM’s (sometimes limited) specifications.

For instance, the 601C has far red if you are looking at playing with Pfr - Pr conversion which allows you to extend the amount of time the lamps are on while in flower. From the graphs, you can get an idea of the ratios between blue/red/far red/ and white.

As a side note, these Heliospectra units have dynamically adjustable spectra such that you can tune the spectra.

I have a some other units to measure including several Fluence fixtures that will be posted here.

[Hoodini]

Wow your definitely going to be my light guru if I ever go indoors lol. . .awesome response I thank you kindy.

[Northern_Loki]

Haha, no. I’m still trying to figure this damn equipment out. Not easy/somewhat confusing to get the measurement apparatus calibrated. But, I figure someone will find this stuff useful.

I’ll be using this data as part of some software for calculating DLI, etc.

[McMuffin]

What’s the difference between these different charts?

[Northern_Loki]

Not certain what you are asking. Are you asking about the Fluence chart?

For one thing, the Fluence chart is relative photometric. Note, normalized and presented in percent. So, from a total PPF specification, you could probably guesstimate the power at any particular wavelength.

If you asking about the Heliospectra charts, those are measured as absolute irradiance. Other than the spectra differences between the two models, the charts detail the irradiance power across the spectra. Absolute irradiance provides a bit more information.

[Northern_Loki]

Added a couple of Fluence “specialty” units to the OP above.

Anyone want to see the measurements from a VyprX plus. Reason I’m asking is because I’d have to measure that one in-situ since it’s currently being used.

[McMuffin]

Can you try to “dumb down” the explaination of what the graphics represent? I think I’m understanding, but not sure…

[Northern_Loki]

That could be something of a rabbit hole but, sure, give me a few moment and I’ll see if I can come up with some background explanation.

[Northern_Loki]

Ok, so what the heck is this stuff?

Equipment
First, the equipment set-up:

What we have here are the following pieces of equipment:

1. Cosine Receptor
2. Spectrometer
3. Low loss broadband fiber optic cable
4. Computer
5. Power Supply

A cosine receptor is an optical device (e.g. lens) that is designed to capture light over 180 degrees. That is, it will collect any light striking the sensor from any angle up to 180 degrees. When you view an object, the light illuminating it is coming from multiple angles. If we want to measure the total light on the object, we want to be able to measure all of the light from all of the incident angles.

A spectrometer is a device that measures radiation (in this case light) by breaking it up into a spectrum. E.g. a rainbow. A linear photodetector in the spectrometer measures the intensity of the spectrum for each of the spectra across our rainbow.
Here’s an image of the internals of a spectrometer. Notice “white light entering” and being broken up into spectral compnents:
[1]

Spectometer:
The photodetector in the spectrometer is read by a computer or some other electronics periodically. The photodector reports the number of photons striking the individual sensor “pixels” as counts.
For example, if we look at the data from the spectrometer, we’d see something like:

Then, on the PC, we can calculate the radiant power based on the “count” for each spectra reported by the spectrometer.
For example, the following is the calculated power based on this data across the spectrum.

Note: To be able to calculate the power, there are several steps involved including the use of calibration coefficients and a bunch of math. I won’t go into that detail here but this is the area where the majority of the errors come from. And, an important thing to note is that the energy of a photon at each spectra differs. Blue has more energy than red.

Now, If we were to integrate the power (add all of the individual spectral power values), we end up with a total power value.

If we wanted to calculate PAR (PFD), we just integrate the values between 400-700nm and throw away anything outside of that range.
If we wanted to calculate YPF, we’d multiply the individual spectra with a YPF weight factor and then integrate (add) between 360-760nm.

At this point, we’ve essentially replicated what amounts to a PAR meter. But, a much more accurate PAR meter with much more information. From this we can extract information for any portion of the spectra and generate any metric.

So, why is this useful?

1. We have the true/exact radiant power striking a surface.

This is not looking at the power consumption of the lamp. Not the efficiency of the LED conversion process. Not some made up metric that some manufacturers provide. Instead, we have the information on the power that is actually going to do work for us. The light energy that is actually striking the surface of a leaf, for instance.

2. We have the power information for all/any portion of the spectrum.

With information from a spectrometer, one could calculate a variety of values such as PAR, YPF, PPE or other metrics that are useful for evaluating whether a light is good for growing plants. We can also evaluate situations where the spectra does not fit nicely into those metrics such as UVA, UVB, far red, infrared, etc. Notice, for example, the sunlight spectra I had captured (see below) is broadband. It has significant energy components outside of PAR, etc. Some of this energy will affect plant morphology and is not included in the standard metrics. The ratios of the energies at the different spectra also affect plant growth (phytochromes,etc). There is a ton of research in this area and they are discovering new things about plant response to different spectra regularly. But, I don’t want to go into detail about that here.

3. Truth in advertising

Not really the point of this OP since the dataset is small but we can determine if the lamp output actually what we were expecting. Again, the OP is not meant to judge that. There could be errors both on my end and the OEM end. Errors or contradiction shouldn’t necessarily be punished but instead should be indicators for following-up and verifying. On the other-hand, gross misrepresentation and out-right dishonesty should be called out.

4. Comparison

For spectrum comparison. See 2. See the sunlight spectrum below and compare this to the lamp spectrum. Compare the individual lamp spectrum to each other. Does the lamp provide the spectrum useful for your situation? Does it provide the amount of radiant power that you’ll need to meet your DLI needs? Is the ratio of the spectra useful for your growth conditions (e.g. in a greenhouse, in a tent, veg vs. flower, etc)? Does something not match up with what the OEMs are telling you? And so forth.

Here are a couple of plots of outdoor sunlight with the detector pointed straight up into the sky.

Sunlight, 11AM EST Northeast US. Current conditions partially cloudy.

Integral radiant (400-700nm): 344.6 W/m^2
Integral radiant (350-840nm): 423.69 W/m^2
PAR (400-700nm): 1171 umol m^2/s
YPF (360-760nm) : 1404 umol m^2/s
PPE: 0.72
Power consumption: Free!

Sunlight Tree Shaded, 11AM EST Northeast US. Current conditions partially cloudy.
Integral radiant (400-700nm): 40.4 W/m^2
Integral radiant (350-840nm): 50.2 W/m^2
PAR (400-700nm): not calculated
YPF (360-760nm) : not calculated
PPE: not calculated
Power consumption: Free!

Hopefully, this helps to explain this a bit more. It’s hard to interpret, I agree, but it also difficult to interpret questions since there is such a great deal of underlying information surrounding this stuff. Answers could go anywhere and in multiple directions… E.g. the rabbit hole.

[McMuffin]

I got really confused for a little bit about the results for the Fluence RAY lights. But then I noticed the spectra used were the UVSpec and PFRSpec. I was like “Where’s the rest of the spectrum??” Derp.

Do you have anything on the SPYDRX or SPYDRX+ with PhysioSpec Indoor?

[anon32470837]

@Northern_Loki

I’ll be using this data as part of some software for calculating DLI, etc.

Very cool toys!!!

But you lost me on this one - DLI ? Daily Licorice Intake, or?

[Northern_Loki]

Haha. Thanks. I’ll relabel the op to make this more clear. If anything, it’ll make people look closer So, good catch.

At this point, I don’t have any other Fluence lamps here except for a Vypr Plus (it’s in use so it’s a bit more painful to measure that one, will get to it).

[Northern_Loki]

DLI: daily light integral or daily licorice intake . Which ever you prefer.

e.g. Daily light integral

Measuring Daily Light Integral in a Greenhouse

Alternatively,

Daily Licorice Intake

[McMuffin]

@Northern_Loki

At this point, I don’t have any other Fluence lamps here except for a Vypr Plus

As long as it has the PhysioSpec Indoor spectrum

[Northern_Loki]

Actually, the one I have is the greenhouse spectra. Bummer.

If anyone is nearby and want’s to loan one out, I could try measuring it for them. For science

[McMuffin]

Let’s see what the greenhouse spectrum looks like and compare it to what Fluence says

[Northern_Loki]

Added a capture of the Vyprx Plus Greenhouse Spectrum (more blues). The sampling was a bit tedious since the light is mounted up near the ceiling in a green house. Required ladders, some duct tape, and a rickety gaffing job. Same deal, 18 inches from the base of the lamp. There was probably a bit of ambient light leaking in but the lamp is so bright it’ll be in the noise. In fact my eyeballs didn’t like it so much even with shades. Posted in the OP.

[McMuffin]

Looks pretty damn close to me! How’s that for truth in advertising?