LH351D 90CRI Spectrum Tests

Flashlight Modding and DIY Parts
84

I sliced two Sofirn sourced 2700K and it lowered the CCT quite a bit :

CCT = 2369K (Duv –0.0014) (Ra) = 95.9 [ R9 = 72.9 ]

This is in a Sofirn IF25 at lowish output (2 LEDs at 50~100lm or something).

This is great because this is exactly what I wanted, a very warm 3535 LED with high CRI, which apparently doesn’t exist.

In the same flashlight (it’s a tint ramping light) I got Convoy sourced 5000K, also sliced :

CCT = 3877K (Duv –0.0004) 93.5 [ R9 = 60.2 ]

I’m surprised of how much the CCT was reduced compared to yours, in your FC11 it reduced to 4500K. In this case 4500K kind of was what I was aiming at for the max CCT in this light, I should probably have gone with the 5700K instead.

85

The TIR in IF25 is quite a bit larger I think than the C01S and C01S is very low output so I suspect those 2 things can cause different results.

As far as the Convoy 5K goes did you measure it before the slice? I assume it’s under 5000K slightly since it’s R2 bin.

86

This was measured at a pretty low output, here is turbo (should be around 3~4A per LED) : CCT = 2437K (Duv –0.0021) (Ra) = 94.0 [ R9 = 65.5 ], and lowest : CCT = 2357K (Duv –0.0013) (Ra) = 96.0 [ R9 = 73.3 ]

I didn’t measure the 5000Ks before slicing them but I’ll put one in another light so I’ll do it now.

87

5000K from Convoy (bin F2R2S2) with beaded TIR :

100 mA CCT = 4693K (Duv 0.0019) (Ra) = 93.4 [ R9 = 62.4 ] IES TM-30-15 Rf = 90.42 Rg = 98.89

1A CCT = 4729K (Duv 0.0026) (Ra) = 92.0 [ R9 = 56.2 ] IES TM-30-15 Rf = 90.17 Rg = 98.87

sliced with beaded TIR:

100mA CCT = 3651K (Duv –0.0016) (Ra) = 93.8 [ R9 = 60.9 ] IES TM-30-15 Rf = 90.88 Rg = 100.11

1A CCT = 3777K (Duv –0.0012) (Ra) = 92.6 [ R9 = 55.9 ] IES TM-30-15 Rf = 90.28 Rg = 100.13

The duv increase at higher current is strange, same behavior in the IF25 I modded with the 5000K leds (the 2700Ks have the classic current up -> duv down), so there is a middle tint point where the duv doesn’t move at all with current changes. The 5000K LH351D in my Wurkkos FC 11 behaves normally ( current up -> duv down)

88

I suspect that “mid point” correlates to the non-linear shape of the BBL?

Edit; and the Convoy LED being closer to 4700K than 5000K makes total sense. It still only changed by ~1000K CCT it just started out much lower than you probably thought.

89

The tint mixes in a straight line :

(disregards the black dot, I don’t know how to display several measurements in Osram colorcalculator without doing the tint mix calculation :person_facepalming: )

“mid point” wasn’t really the right word, but at around 2800K the duv doesn’t change with current, under that it goes down with current (behavior of the 2700K lh351d from Sofirn), above it goes up with current (behavior of the 5000K lh351d from Convoy)

I was under the impression that 1000 CCT was still quite a lot ? Maybe it’s because I sliced it very low ?

90

Here is the point I was trying to make and it’s just a hunch I do not know enough to be sure this is even true:

Lets say as we increase current it always makes this same slant (yes I oversimplified it). At some point our slant starts to become parallel with BBL at higher CCT so we will no longer have the change in Duv since Duv is fixed to BBL while at lower temps it is almost perpendicular to BBL.

91

Ah ok I understand, here are the 2 leds in the IF25, at lowish, midish and turbo :


(forgot to add the output on it, but higher CCT means higher output, and again please ignore the black dots and lines)

So indeed the inclination between the two is similar, and for the higher CCT one it crosses the BBL, since the tint shift is not very angled in the first place for LH351Ds. (I’m not sure those are the right words, English isn’t my first language)

Aside from that, I was curious about the effect on tint depending how low the slicing is, this is with the LED from the wurkkos FC11, with the same beaded TIR as previously :

Original :

0.1A CCT = 4769K (Duv 0.0058) (Ra) = 91.2 [ R9 = 51.0 ]
0.5A CCT = 4826K (Duv 0.0061) (Ra) = 90.5 [ R9 = 48.2 ]
1A CCT = 4875K (Duv 0.0059) (Ra) = 90.2 [ R9 = 46.4 ]
2A CCT = 4917K (Duv 0.0055) (Ra) = 89.7 [ R9 = 43.9 ]

(so actually even with this bin the duv doesn’t decrease a lot, even goes up a bit at 0.5A

Washer thickness of 1.52mm :

0.1A CCT = 4544K (Duv 0.0050) (Ra) = 91.4 [ R9 = 51.6 ]
0.5A CCT = 4605K (Duv 0.0051) (Ra) = 90.8 [ R9 = 49.0 ]
1A CCT = 4680K (Duv 0.0046) (Ra) = 90.5 [ R9 = 47.6 ]
2A CCT = 4706K (Duv 0.0044) (Ra) = 90.0 [ R9 = 44.6 ]

1.20mm :

0.1A CCT = 4343K (Duv 0.0031) (Ra) = 92.0 [ R9 = 54.3 ]
0.5A CCT = 4405K (Duv 0.0034) (Ra) = 91.4 [ R9 = 51.6 ]
1A CCT = 4462K (Duv 0.0032) (Ra) = 91.0 [ R9 = 49.7 ]
2A CCT = 4525K (Duv 0.0027) (Ra) = 90.5 [ R9 = 47.2 ]

1.00mm :

0.1A CCT = 4083K (Duv 0.0019) Index (Ra) = 92.3 [ R9 = 54.9 ]
0.5A CCT = 4147K (Duv 0.0023) (Ra) = 91.7 [ R9 = 52.2 ]
1A CCT = 4202K (Duv 0.0022) (Ra) = 91.2 [ R9 = 50.1 ]
2A CCT = 4293K (Duv 0.0017) (Ra) = 90.7 [ R9 = 47.4 ]

0.85mm :

0.1A CCT = 3798K (Duv 0.0023) (Ra) = 92.2 [ R9 = 52.6 ]
0.5A CCT = 3859K (Duv 0.0026) (Ra) = 91.5 [ R9 = 50.1 ]
1A CCT = 3918K (Duv 0.0025) (Ra) = 91.0 [ R9 = 48.0 ]
2A CCT = 4017K (Duv 0.0020) (Ra) = 90.4 [ R9 = 45.2 ]

0.85mm is the thickness I used previously, on this one it shaved a tiny amount of phosphor on one side so the results might be skewed a bit, although looking at the led at very low output I don’t see any irregularities, it hasn’t happened before, maybe this led was soldered slightly higher.

So the 1000K reduction was because it was a close shave.

92

I did an relative output test depending on washer thickness yesterday, I’m not sure if it’s still on topic for this thread or if I should post another one ?

With LH351D bin F2R2S2 from Convoy, washer thickness of 1.26mm :

0.1A 89.2%
0.5A 89.5%
1A 89.6%
2A 89.5%
3A 89.3%

1.00mm :

0.1A 84.5%
0.5A 84.6%
1A 84.2%
2A 84.4%
3A 82.5%

0.85mm :

0.1A 80.8%
0.5A 81.1%
1A 80.9%
2A 80.5%
3A 79.6%

I feel that around 1mm is a pretty good spot since there are no duv gain going further down, while the output continue to decrease.

93

Kaidomain 5700K @ 1A w/ Frosted TIR:

94

According to the picture in the simon’s store, the last one should be V2Q1S2

95

Updated. His description does not match the picture

96

Please test Simon’s 4000k.

97

I received some more 5000K from Convoy and they are not as good as the ones I got previously, before they were around duv 0.0020~0.0030 at 100mA, now around duv 0.0035~0.0050, It makes me wonder if its the same reel as before or a new one with a different color bin, this is quite disappointing.

I got some 5700K too, but there have been a mistake because they test the same as the 5000K.

Here is another one 2700K from Sofirn to compare with contactcr one, same beaded TIR as before (same distance, so lux can be compared) :

0.1A Ambient = 1726.1 Lux, CCT = 2701K (Duv 0.0013)
Color Rendering Index (Ra) = 95.9 [ R9 = 74.5 ]
IES TM-30-15 Rf = 94.10 Rg = 99.50

0.5A Ambient = 6778.6 Lux, CCT = 2714K (Duv 0.0010)
Color Rendering Index (Ra) = 95.5 [ R9 = 73.0 ]
IES TM-30-15 Rf = 94.00 Rg = 99.99

1A Ambient = 12251.9 Lux, CCT = 2722K (Duv 0.0007)
Color Rendering Index (Ra) = 95.1 [ R9 = 71.5 ]
IES TM-30-15 Rf = 93.61 Rg = 100.34

2A Ambient = 21058.3 Lux, CCT = 2720K (Duv –0.0003)
Color Rendering Index (Ra) = 94.5 [ R9 = 68.4 ]
IES TM-30-15 Rf = 92.71 Rg = 100.80

Sliced 1mm :

0.1A Ambient = 2298.4 Lux, CCT = 2435K (Duv –0.0013)
Color Rendering Index (Ra) = 96.0 [ R9 = 74.0 ]
IES TM-30-15 Rf = 93.27 Rg = 101.86

0.5A Ambient = 9113.0 Lux, CCT = 2448K (Duv –0.0016)
Color Rendering Index (Ra) = 95.5 [ R9 = 72.0 ]
IES TM-30-15 Rf = 92.54 Rg = 102.25

1A Ambient = 16433.9 Lux, CCT = 2459K (Duv –0.0019)
Color Rendering Index (Ra) = 95.1 [ R9 = 70.2 ]
IES TM-30-15 Rf = 91.87 Rg = 102.53

2A Ambient = 28013.9 Lux, CCT = 2464K (Duv –0.0027)
Color Rendering Index (Ra) = 94.3 [ R9 = 66.6 ]
IES TM-30-15 Rf = 90.77 Rg = 102.79

98

So how green are new 5000k ones from Convoy?

99

To put his numbers into perspective 0.003 to 0.0035 DUV is about “average” for most LH351D’s we have seen but the higher end of his range gets into the “overly” green territory.

100

That’s unfortunate. At the beginning of August I ordered some too because the product page specifically stated SPHWHTL3DA0GF4RTS6 Bin F2R2S2, which I thought was the most desired. Unfortunately I have no way to test them other than to visually compare to my Sofirn SP36 5000K. I’ll have to do that eventually… I wonder if/when the old stock ran out and new bin started being sold.

I really appreciate when vendors specify the actual LED bin, but always have to question the age of the information…

101

I ordered the 1st ones early August, the seconds early September.

102

Since Sofirn sourced 2700K were nice I bough some more to put in some light bulbs, I also took one 5000K and 4000K to see how they test :

4000K :

0.1A Ambient = 1829.6 Lux, CCT = 3905K (Duv 0.0044)
Color Rendering Index (Ra) = 92.9 [ R9 = 72.9 ]
IES TM-30-15 Rf = 91.51 Rg = 99.27

0.5A Ambient = 7292.8 Lux, CCT = 3928K (Duv 0.0037)
Color Rendering Index (Ra) = 92.4 [ R9 = 71.5 ]
IES TM-30-15 Rf = 91.43 Rg = 99.85

1A Ambient = 13191.3 Lux, CCT = 3943K (Duv 0.0030)
Color Rendering Index (Ra) = 92.1 [ R9 = 70.7 ]
IES TM-30-15 Rf = 91.18 Rg = 100.29

2A Ambient = 22691.5 Lux, CCT = 3956K (Duv 0.0013)
Color Rendering Index (Ra) = 92.2 [ R9 = 70.1 ]
IES TM-30-15 Rf = 90.81 Rg = 100.58

5000K :

0.1 Ambient = 2210.7 Lux, CCT = 4730K (Duv 0.0030)
Color Rendering Index (Ra) = 92.7 [ R9 = 58.1 ]
IES TM-30-15 Rf = 89.52 Rg = 97.55

0.5 Ambient = 8847.3 Lux, CCT = 4817K (Duv 0.0038)
Color Rendering Index (Ra) = 91.8 [ R9 = 54.3 ]
IES TM-30-15 Rf = 89.75 Rg = 97.91

1 Ambient = 16101.2 Lux, CCT = 4870K (Duv 0.0039)
Color Rendering Index (Ra) = 91.3 [ R9 = 51.7 ]
IES TM-30-15 Rf = 89.70 Rg = 98.05

2 Ambient = 28038.4 Lux, CCT = 4949K (Duv 0.0037)
Color Rendering Index (Ra) = 90.7 [ R9 = 48.7 ]
IES TM-30-15 Rf = 89.47 Rg = 98.33

103

thefreeman, work your magic and see if Arrow will reveal what their 4 in stock 90 CRI bins are: arrow results

I’ve never seen anyone able to get this info so you must have the magic touch.