Comparing 20 LEDs (with and without high CRI) in 14 Convoy s2+: final personal observations

LED Flashlights – General Info
61

I tried some Luxeon V 4000K emitters and loved them, despite being only 70 CRI. When the HL2X released I bought several of them in 3000K & 4000K, and each in 70 & 80 CRI. The 3000K emitters were all so bad I didn’t even bother trying the 4000K ones!

62

Is there even any reliable source where we can get rosy V and V2 when L4P is closed?

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Short answer: no.
I’ve never had experience with the V or V2, actually. I personally never go low cri except for throwers. I did however try 80 and 90cri HL2X and they were terrible with regard to tint and even worse angular tint shift. Like xpg3 levels of tint shift at the periphery.

64

I’ve had the V2 in 3000, 4000, and 5000K in a S2+ triple and was not impressed. The angular tint shift is pretty bad, yellow/green center. After swapping in XPL HI’s in the same color temps, there is noticeable increase in output and complete elimination of angular tint shift. The CRI is noticeably better too.

65

I didn’t mix these leds but the V2 4000k I bought from the L4P are rosy. A huge difference compared to the V2 4000k from Mouser, which are a bit greenish.

66

Received my order of 14 Convoys yesterday.. But I also noticed that the 219C only has 4*7135's instead of the 8 that I got for the others. hmmm

anyway.

Will first test all these lights in terms of CCT and CRI, before replacing the LEDs with the ones I bought separately.

They all look pretty similar with some very tiny differences (by eye).

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Nice! Looking forward to it. The slugfest of LEDs…who will ‘win?’

68

Just sharing some of the first observations. I'm a little bit tired, so I have problems making normal sentences :D

1. It's really tough to get consistent readings when it comes to DUV. the DUV measurements seem to change a lot between measurements. Sometimes ranging between 0.0019 and 0.0039 isn't abnormal in my first few tests. I'm not so much into DUV, so maybe this isn't as big a difference as I think. Any comments on this?

2. CCT and Ra are usually relatively close, but it's not uncommon to see 94.2 and 95.5 between the 2 measurements (1 with the frosted glass on top of the Opple, and 1 measurement with the frosted glass about 7cm away from the Opple..

FYI: I added a frosted glass in front of the Opple, to get a more consistent reading.. I thought... I had the lights about 70cm from the light meter.

I'm first just testing the 13 SST20's to see which is the closest to the BBL... (and that's hard to measure, because the one I had originally tested with the closest number to 0, was different the second time I tested)

3. third observation: I took 2 lights (that were close together in terms of DUV and CCT), but with a slight difference in the spill when they were held side by side, but not so much of a difference in the hotspot!!!
1 was very slightly towards green, while the other was slightly towards red.... It's just slighly, but the DUV I measured didn't indicated any negative reading -0 .

I probably have to add DC Fix soon to get possible some more consistent readings?

So the problem is: you can't hold the light in front of the lux meter because it will be too bright. So maybe DC fix is the only solution?

The other problem is, if it would be possible to hold it close to the Lux measurement, the light will be a mix of hotspot and spill, and won't necessarily tell how you would perceive it in person!

This comparison is not going to be about 'measurements' persé, but testing a combination of what people are arguing here, and what I perceive as an enjoyable tint... and see if CRI is that important like some people make it to be.

So I'll keep going and see if I can make up my mind of what I prefer. This is not going to be to see which LED is closest to the BBL, becaue that's already busted with my few dozen measurements. Each time it will be different, and how important is the spill for the measurement if you won't notice that in person in the fild anyway, unless you try to enjoy the whole beam instead of the thing you are pointing at.

I'm just trying to make up my mind along the way, so these are just observations, and I hope to learn more and get a better grip of what I'm doing :D

69

I have no Opple so I can not comment on the workings, but you mention frosted glass, and you suggest dcfix. Mind that any type of diffusing will remove some blue out of the spectrum so at least the CCT will be changed by it (to warmer CCT).

70

Interesting results. Thanks for sharing the preliminary results.
Maybe this will help a bit, but here’s how I test with the Opple…

I turn off all the lights and test in a wide open space with nothing around to possibly reflect light. Set the Opple on the ground, sensor up. Hold the light directly above the sensor. I do 0.8 meters, it has to be consistent and the light must be in the same position each time and testing the same mode/current. A you should let the light run for 20 or so seconds so the output stabilizes. Try to keep it steady so the reading doesn’t fluctuate much and wait for it to stabilize before taking the reading. It should help at least minimize the light/sensor poaition as a variable. Ideally you want to measure at the point to where the hotspot is fully focused and saturated (fully converges) to help minimize possible angular tint shift. A LOP reflector would help I think.

71

Thanks for the comments and tips...

Yeah, those things are definitely possible. I will do some more testing, and maybe start with a low mode pointing directly at the sensor, and see what kind of variations I see then.

What do you all think about a 'combined' reading? spill and hotspot? I don't think that is very helpful in real life situation. People usually don't look at the spill, and the change is so small, that it might only be visible if you really concentrate on it. And that's not what flashlights are made for :D

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Some more observations with testing... just sharing.. to keep things in this thread.

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#2 1 with frosted glass on top of the Opple Highest 0.8m 7,811 3,951 93.9 0.3848 0.3851 0.0026
2 the edge of the hotspot no frosted glass Highest 0.8m 3,220 4,058 95.6 0.3778 0.3733 -0.0008
3 direct, center 15 seconds Highest 0.8m 7,830 3,863 94.6 0.3867 0.3793 -0.0006
4 direct, center start Highest 0.8m 8,252 3,958 94.4 0.3838 0.3824 0.0017
5 direct, center 30 seconds Highest 0.8m 7,873 3,885 94.5 0.3859 0.3795 -0.0003
6 direct, center, few seconds Highest 0.5m 22,295 3,925 94.2 0.3852 0.3829 0.0015
7 direct, center, few seconds mode 2? 0.3m 18,126 4,077 95.6 0.3802 0.3862 0.0044
lowest 3,863 93.9 -0.0008
highest 4,077 95.6 0.0044
Difference % 6% 1.80% Difference 0.0052

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#3 1 with frosted glass on top of the Opple Highest 0.8m 6,973 3,984 95.1 0.3838 0.3862 0.0034
2 the edge of the hotspot, directly, no glass Highest 0.8m 1,865 4,089 96.4 0.3781 0.3795 0.0020
3 without frosted glass, center 15 seconds Highest 0.8m 7,650 3,974 95.3 0.3741 0.3860 0.0032
5 without frosted glass, center 30 seconds Highest 0.8m 7,193 3,912 95.5 0.3858 0.3832 0.0015
6 direct, center, few seconds Highest 0.5m 24,688 3,986 95.7 0.3827 0.3822 0.0019
7 direct, center, few seconds mode 2? 0.3m 14,854 4,106 95.7 0.3793 0.3870 0.0052
lowest 3,912 95.1 0.0015
highest 4,106 96.4 0.0052
Difference % 5.0% 1.40% Difference 0.0037

Only 1 mode in sphere:

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#2 1 Sphere testing, reflect front Middle, 2 on the edge 2,521 4,147 94.9 0.3751 0.3756 0.0011
2 sphere testing, reflect left Middle, 2 on the edge 2,110 4,147 94.8 0.3753 0.3764 0.0014
3 sphere testing, reflect back Middle, 2 on the edge 2,052 4,131 94.8 0.3759 0.3766 0.0013
4 sphere testing, reflect right Middle, 2 on the edge 2,098 4,113 95.1 0.3765 0.3762 0.0009
lowest 4,113 94.8 0.0009
highest 4,147 95.1 0.0014
Difference % 0.80% 0.30% Difference 0.0005

#3 1 Sphere testing, reflect front Middle, 2 on the edge 2,412 4,197 95.8 0.3741 0.3794 0.0032
2 sphere testing, reflect left Middle, 2 on the edge 2,049 4,186 95.7 0.3747 0.3800 0.0032
3 sphere testing, reflect back Middle, 2 on the edge 1,990 4,186 95.8 0.3746 0.3798 0.0032
4 sphere testing, reflect right Middle, 2 on the edge 2,084 4,154 96.0 0.3758 0.3800 0.0029
lowest 4,154 95.7 0.0029
highest 4,197 96.0 0.0032
Difference % 1% 0.30% Difference 0.0003

and now compared 3 modes in sphere..

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#2 1 Sphere testing, reflect front Middle, 2 on the edge 2,521 4,147 94.9 0.3751 0.3756 0.0011
2 sphere testing, reflect left Middle, 2 on the edge 2,110 4,147 94.8 0.3753 0.3764 0.0014
3 sphere testing, reflect back Middle, 2 on the edge 2,052 4,131 94.8 0.3759 0.3766 0.0013
4 sphere testing, reflect right Middle, 2 on the edge 2,098 4,113 95.1 0.3765 0.3762 0.0009
5 Sphere testing, reflect front Low 1 on the edge 516 4,081 95.1 0.3783 0.3788 0.0016
6 Sphere testing, reflect left Low 1 on the edge 453 4,092 95.2 0.3778 0.3788 0.0017
7 Sphere testing, reflect front High 3 on the edge 11,724 4,043 94.7 0.3783 0.3732 -0.0010
8 Sphere testing, reflect left High 3 on the edge 10,187 4,025 94.6 0.3790 0.3734 -0.0012
lowest 4,043 94.6 -0.0012
highest 4,147 95.2 0.0017
Difference % 2.60% 0.60% 0.0029

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#3 1 Sphere testing, reflect front Middle, 2 on the edge 2,412 4,197 95.8 0.3741 0.3794 0.0032
2 sphere testing, reflect left Middle, 2 on the edge 2,049 4,186 95.7 0.3747 0.3800 0.0032
3 sphere testing, reflect back Middle, 2 on the edge 1,990 4,186 95.8 0.3746 0.3798 0.0032
4 sphere testing, reflect right Middle, 2 on the edge 2,084 4,154 96.0 0.3758 0.3800 0.0029
5 Sphere testing, reflect front Low 1 on the edge 380 4,122 96.6 0.3773 0.3813 0.0031
6 Sphere testing, reflect left Low 1 on the edge 328 4,118 96.5 0.3776 0.3819 0.0032
7 Sphere testing, reflect front High 3 on the edge 11,870 4,077 95.7 0.3777 0.3761 0.0005
8 Sphere testing, reflect left High 3 on the edge 10,301 4,073 95.6 0.3779 0.3764 0.0006
lowest 4,073 95.6 0.0005
highest 4,197 96.5 0.0032
Difference % 3.00% 0.90% 0.0028

Oh, and this is just from 1 type of LED..

It's possible that the differences grow bigger when I check other LEDs...

Maybe I shouldn't measure with the frosted glass anymore?!?

73

More observations:

From this testing, I think I can say that the DUV can be off up to 0.0050 depending on how you measure, what mode you use, etc

so one of my first conclusions: the DUV isn't a very trustable number across the board. Hard to compare with other reviewers that use different techniques.

But I don't know if 0.0050 is a big number in terms of DUV?

CCT and CRI

CCT and CRI are more consistent, and are likely more comparable between reviewers with the Opple Light Master

My initial testing has a max of 6% difference in CCT. I know that it can go a bit higher, but I doubt it will hit 10%

Ra (CRI) : It's interesting to note that the CRI has the lowest difference in all the measurements:

With frosted glass on top of the Opple, edge of hotspot, inside sphere, direct lighting...

And the mode also influences the measurement.

Time

It also seems to matter When to measure.. after a few seconds, or after 30 seconds.

Quick summary:

I trust CCT and CRI measurements with the Opple, by different users, more than I trust DUV measurements.

That's an early conclusion.. :D

So, when somebody says: my DUV is X..or your DUV is bad.... you really have to ask: how did you measure, what mode did you use, what's the distance etc, how many seconds after turn on. I think there are just a bit too many variables here.

For CCT: I can just think: hmmm that could be about 6%+ off

For CRI: I can just think: hmm that could be about 2% off.

More testing to come

74

0.0050 is a fairly big number, +0.0050 can be the difference between on top of the BBL and greenish, or –0.0050 the difference between on the BBL and visibly rosy.

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The biggest difference has to do with: used frosted glass, mode, and time of measurement.

3 variables

76

I’m guessing some of those duv differences have to do with R9 and higher…?

77

With the Opple being a bluetooth device, there’s no need for it to be at close proximity other than when measuring very low outputs.

More distance = bigger hotspot = less variance in results as it’s easier to keep the Opple centered in the hotspot

DC-Fix on the light might be ok, but I’d avoid softening the Opple end - it already has a white surface in front of its sensors. A separate frosted glass will make it harder to compare results with others.
For most real-life relevant results I’d also avoid averaging devices like the sphere. A sphere is sensible for measuring lumens, but less so when it comes to color. Separate measures for hotspot, corona and spill could be useful, depending on the beam profile.

To lessen the effect of random variance, several (3-6?) measurements and averaging the results might be best.

For my personal testing, I’ve had the Opple on a stand around 2.5m from the light. With Opple casting a shadow on the wall 1.5m behind it, it’s very easy to see when the Opple is in the absolute center of the hotspot. Though with throwers even 2.5m might be too close.

78

Next round.

Testing the influence from the original Anti Refective coated lens vs clear glass.

Just showing data for some proof...

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#2 1 Sphere testing, reflect front Middle, 2 on the edge 2,521 4,147 94.9 0.3751 0.3756 0.0011 original
2 sphere testing, reflect left Middle, 2 on the edge 2,110 4,147 94.8 0.3753 0.3764 0.0014 original
3 sphere testing, reflect back Middle, 2 on the edge 2,052 4,131 94.8 0.3759 0.3766 0.0013 original
4 sphere testing, reflect right Middle, 2 on the edge 2,098 4,113 95.1 0.3765 0.3762 0.0009 original
lowest 4113 94.8 lowest 0.0009
highest 4147 95.1 highest 0.0014
Difference 0.0005
Difference 0.80% 0.30% Average 4 measurements 0.0012

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#2 1 Sphere testing, reflect front Middle, 2 on the edge 2307 4118 94.9 0.3757 0.3739 0.0001 clear glass
2 sphere testing, reflect left Middle, 2 on the edge 2071 4112 94.9 0.376 0.3742 0.0001 clear glass
3 sphere testing, reflect back Middle, 2 on the edge 1933 4093 95.2 0.3766 0.3738 -0.0002 clear glass
4 sphere testing, reflect right Middle, 2 on the edge 1975 4098 95.0 0.3765 0.3741 -0.0001 clear glass
lowest 4093 94.9 -0.0002
highest 4118 95.2 0.0001
Difference 0.0003
Difference 0.60% 0.32% Average 4 measurements 0.000025

Difference between AR and clear glass:

Convoy # Original glass vs Clear glass lowest of 8 measurments 4,093 94.8 - - -0.0002
#2 highest of 8 measurement 4,147 95.2 - - 0.0014
Difference 0.0016
Difference 1.30% 0.40% Difference between Avg with and without 0.0012

The AR coated lens influenced DUV by an average of 0.0012 on this light

CCT could be influence by an average of 1.3%

and CRI could be influenced by average of 0.4%

Notice that DUV without the glass lens... that's about as perfect as it can get, correct?

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Light #3

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#3 1 Sphere testing, reflect front Middle, 2 on the edge 2,412 4,197 95.8 0.3741 0.3794 0.0032 original
2 sphere testing, reflect left Middle, 2 on the edge 2,049 4,186 95.7 0.3747 0.3800 0.0032 original
3 sphere testing, reflect back Middle, 2 on the edge 1,990 4,186 95.8 0.3746 0.3798 0.0032 original
4 sphere testing, reflect right Middle, 2 on the edge 2,084 4,154 96.0 0.3758 0.3800 0.0029 original
lowest 4154 95.7 0.0029
highest 4197 96.0 0.0032
Difference 0.0003
difference: 1.00% 0.30% Average 0.0031

Clear glass

Convoy # Measurement Mode Distance Lux CCT Ra X Y DUV
#3 1 Sphere testing, reflect front Middle, 2 on the edge 2249 4139 95.8 0.376 0.3785 0.0021 clear glass
2 sphere testing, reflect left Middle, 2 on the edge 2020 4140 95.8 0.376 0.3787 0.0022 clear glass
3 sphere testing, reflect back Middle, 2 on the edge 1882 4134 95.8 0.3763 0.3787 0.0022 clear glass
4 sphere testing, reflect right Middle, 2 on the edge 1942 4110 96.0 0.3771 0.3788 0.0020 clear glass
lowest 4110 95.8 0.0020
highest 4140 96.0 0.0022
Difference 0.0002
difference: 0.73% 0.20% Average 0.002125

And average difference between With and Without AR coated glass lens

Convoy # Original glass vs Clear glass lowest 8 measurements 4,110 95.6 0.0020
#3 highest of 8 measurements 4,197 96.0 0.0032
Difference 0.0012
Difference 2.12% 0.42% Difference Avg with and without 0.0010

CCT average difference of 2.12% between all the different ways of measuring

CRI only an average difference of 0.42%

DUV difference of average 0.0010

80

So AR coated has about 2% effect on the CCT and 0.5% on CRI, and about 0.0011 average on DUV

Edit:

Light #2

I just took the average of CCT with AR coated lens = 4135

And then took average CCT with CLEAR lens = 4105

Difference is 4135-4105= 30

That's really just a small difference.

Light #3

I just took the average of CCT with AR coated lens = 4181

And then took average CCT with CLEAR lens = 4130.75

Differce is 4181-4130.75 = 50.25

That's also just a very small difference.

So just from these 2 test, AR coated lenses don't change CCT much

CRI

Light #2

I just took the average of CRI with AR coated lens = 94.9

And then took average CRI with CLEAR lens = 95.0

Difference is 95.0-94.9 = 0.1

That's really just a small difference.

Light#3

I just took the average of CRI with AR coated lens = 95.8

And then took average CRI with CLEAR lens = 95.9

Difference is 95.9-95.8=0.1

That's really just a small difference.

So my conclusion: AR coated lenses don't influence CRI much