Great point/question (I did sense you were heading this way :) :+1: ). So if I understand you correctly… if max output of the 2 lights, S21D with four 219b’s and M21B with one GT-FC40 are similar, both around 2000 lumens (here and here), then how is it I kept saying the S21D does not come remotely close to M21B when it comes to brightness perception and throw? It would be great if S21D with narrow angled TIR equals M21B that way we could just buy the S21D (Nichia 219b with throw!) and forget M21B.
I am absolutely no expert and don’t know the definitive answer but do think it has to do with the design difference, 4 LED’s with TIR (S21D) vs 1 LED with reflector (M21B), the LED itself (one is dome, the other flat), and how lab measurement translates into brightness perception of hotspot and spill. That’s the limit of my amateur-level knowledge and any expert here pls chime in as needed if you feel like it.
More importantly though, I can prove my observation: with beam shots of the two lights of an actual scene so you could see for yourself the significant brightness difference. (Pics coming.)
Here we go: M21B w/ single GT-FC40 versus S21D w/ four Nichia 219b’s.
Shot w/ Canon DSLR, identical settings for both lights: ISO 320, f/2.8, 1/3 sec, WB 5000k.
Batteries used were Samsung 40T at full charge for both flashlights.
This is a hill in front of my house and that tree in the middle of the picture is about 30 yards from my camera. Yes unfortunately it does look like that in real life; there is simply no comparison at all wrt brightness and throw. I will post pic of Nichia 519a later but from eyeballing, it’s going to be a “kill” also. The idea is great, why shouldn’t we buy Quad Nichia 219b with throwy optic and skip GT-FC40, but unfortunately the design and LED are not conducive, at least not in a small light.
As much as I love S21D, it’s more useful inside house or close field, and brightness is on low end of flashlights. M21B otoh is useful both inside (because it is quite floody also) and outside (because it has a much, much better throw and brightness). The trio M21B, E, and F have what I call a balanced beam with good hotspot (throw) AND good spill (flood), making them the perfect all-around all-star or gift light. Were I to start a collection again, they would be the first light I’d buy (well together with Nichia 219b 4500k lol).
In my M21B with that XHP70.3 Hi cri is ~95 with Opple and DUV is –0.0020 to –0.0040 depending of output level. CCT averages 5400K. And efficiency is about double to GT-FC40.
Congrats on finding a light you love, but that CCT would be a negative for me. I find beam color above 4500k sterile and “flat.” Even at 5000K my Wurkkos 219c, as neutral as it is, is not a favorite light and barely used. The only time I happily tolerate high CCT is for super throwers like the Wurkkos SBT90.2. Strictly personal preference so no right or wrong.
BTW after my experience with Cree XHP35 HI and XHP70.2 NW (both green hell), I now tend to stay away from Cree LED’s unless/until trustworthy reviewers discuss the beam color and quality, and even then would only buy it from a vendor that allows easy return like Amazon.
Re. Opple, as much as I love it, as noted above, IMvHO its numbers are no replacement for actual real life observation or photography comparison. So far (ie subject to change with further use) I have found my Opple to read Duv’s that tend to be more negative than what Simon measured.
the 4 LEDs spread their light over a larger area, more dimly. the single LED focuses its light into a smaller area, that is illuminated more brightly
it is a Lumens vs Lux issue:
note both beams are the same total lumens, but spread over different size areas
those beam spread differences also impact battery life. A multi LED light will eat batteries faster, because it is illuminating a wider area, but more dimly, so the operator turns up the Lumens, in hopes of getting more LUX on target. It does not work very well outdoors. More lumens just floods the near field of vision with more light, still failing to project a more intense beam on a more distant target
I also found 5000K LH351D too “washed out”. Same for 5000K 219C.
I discovered R9 CRI differences account for it
the 5000K 519a is quite a bit nicer than 5000K 219c and 5000K LH351D, due to higher R9 CRI.
I had that Cree LED, but second version XHP 70.2 ,and in “Neutral White” CCT. That particular LED was the worst green hell in my light collection. It was going back to Amazon even if the efficiency were quadrupled . Kidding aside, IMHO low efficiency is part and parcel of high CRI with great tint LED (that article you quoted even mentioned it). I am not surprised that any other LED have higher efficiency than GT-FC40 or Nichia; in other words, good to know, but personally, low on the “priority” list.
It seems they have fixed the tint shift for Cree 70.3? For fun, please post pics of beam shots of this 70.3 next to your GT-FC40 and Nichia 219b. I don’t care too much for CCT 5400 (too flat and “sterile”) but would be interesting nevertheless.
BTW with 519a and GT-FC40, preliminary trials with my Opple appear to show Duv MORE negative and Ra ~ 4 points higher than what Simon measured (219b results are closer). Whether this is due to LED variation, measurement difference, or systemic error of the device, I don’t know. But personally at this point, other than CCT, I still take other Opple results with a small grain of salt. I trust photography comparison more, for example.
Yeah,Opple is Opple. It isn’t lab tool for sure. I’ve bought about 10 different bins of these 70.3 Hi’s for testing. This 2D 90cri is the best one by far. These are domeless, so no tint shift.
Hardest part is to find a bin, that has them all. Tint, cri and effiency. I would have preferred this to be little warmer but this tint is so clean white, that I don’t care.
With GT-FC40’s it’s also lottery if you get a good one. I have bought 5 4500K versions at three separate occasions and first 2 of them were good really good, rest were green. I also have 2 3000K versions. Both green. And sustained output and throw of these wasn’t enough for my use case.
I will soon receive few more of these. Hopefully they still are the same bin, because they sold out fast last time and I only bought one for testing purposes.
I took beam shots of the 2 lights to show the different beam angles. S21D almost 180 degree spread. Still I am a little surprised the difference in throw and overall brightness perception.
The S21D in this picture has the more throwy Sofirn IF25a lens btw.
1. I do find its reading of CCT, brightness, and Ra very helpful (if possibly a little optimistic with the Ra sometimes). It’s the Duv that I am a little cautious about and I still think back to back “real life” comparison or photography are more “reliable” ways to compare LED colors (not Opple Duv reading).
2. Wow - did you buy LED, or are these actually 5 separate Convoy lights :+1: ? If you buy LED’s, it’s understandable that the bins might be different, as with Cree or any other brand. That said my 4 Convoy GT-FC40 lights have beams that are instantly recognizable as belonging to same family. Even the Duv readings (posted above), if possibly not accurate, are at least consistently negative.
I always knew from real-life use that the GT-FC40 has a purple/magenta tint, but have not been able to capture this color on its beam shots (they always look more brownish - see picture above). This has been a puzzle to me, that photography doesn’t support what I see.
But I’ve finally cracked the code, by way way UNDER-EXPOSING the central area of the beam, which usually is very bright.
Below are beam shots of my two M21F’s, one with the very negative (Nichia 219b-range) Duv of –0.015, and the other a more moderate Duv of 0.0050. The magenta/purple tint is clearly captured. Now there is no doubt; finally I’ve exposed the Nichia imitator lol. Equally great that the M21F light with the more negative Duv is actually more magenta ie photography correlates with Opple’s measurements.
Still burns me how CCT can vary so much with a given emitter, by production batch. Manufacturers really need to aim for greater consistency… but, I guess it all comes down to tolerance & demand. There aren’t nearly enough people OCD on tint.
I did not record the x,y coordinates the first time (prob too excited with the then new arrival Opple Light Master Pro/Series III) so re-ran the test a few weeks later. Yes you read correcly somehow I did end up with four GT-FC40 lights :person_facepalming: lol.
Continued to be impressed with the Opple’s consistency. An absolute must have for enthusiasts IMHO - who don’t want to spend more than 40 bucks that is. Make sure to click on the picture that says Pro (3) Page Not Found - Aliexpress.com
I have the one GT-FC40 outlier that has very negative Duv of –0.0148, in the range of Nichia 219b 4500K (you could even see it in the beamshot above Click HERE ). Overall I would expect the Duv to be less negative, in the range of –0.0060 as seen in the other 3 GT-FC40’s that I have. CCT of all 4 is in the ideal range for an all-around EDC with soothing yet clear beam color - 4500K.
Second Run:
M21B
CCT 4579 Ra 98.7
x 0.3560 y 0.3466 –0.0068
M21F
CCT 4370 Ra 97.9
x 0.3595 y 0.3339 Duv –0.0148 (!!)
M21F (second light)
CCT 4481 Ra 98.4
x 0.3591 y 0.3491 Duv –0.0066
M21E
CCT 4395 Ra 98.2
x 0.3623 y 0.3520 Duv –0.0063
If you own any of these Convoy lights and the lens does NOT reflect green (apparently earlier ones had purple reflection), check out this comparison between the Convoy AR lens w/ green reflection and a UCL lens with purple reflection +*HERE and white-wall beamshot HERE .
Summer is gone so it’s time we take the flashlights out for our evening walk. I know I sound like a Convoy salesman at times (or always lol), and sorry but I can’t help it! . Many times it feels like Simon knows what I want and make a light for me.
At any rate the M21E with GT-FC40 has everything that I could ask for: beautiful color rendition, warm beam color, perfect throw range. It is bright but not too blinding to people in opposite direction (they hate my Nitecore with SST40 6000k). If you are new to flashlights this should be the first light to buy IMHO. A true perfect all around EDC. If you don’t believe me please just google “GT-FC40 review” and read the raves.
Most people would probably prefer M21F (less cumbersome, prettier) but because my older eyes like everything bright, I have a slight preference for E. Also IMHO warmer CCT LED like this 4500k needs to be a little brighter than 6000k LED for better scene “clarity”.
Here is the light next to a 60 year old watch I inherited from my father. Due to life circumstance (war & immigration) it sat un-used for 30-40 years. I sent it to Omega service to restore and they asked me what happened, did owner wear this watch lol. They did a wonderful job, down to original Omega leather band. Amazing that this old watch is still off by only a few seconds per day.
or gift light. Were I to start a collection again, they would be the first light I’d buy (well together with Nichia 219b 4500k lol).
. Many times it feels like Simon knows what I want and make a light for me.