The S21D 8A doesn’t step down in 35% mode, but the 12A does step down in 35% mode. The 8A has very impressive sustained brightness/size, but will run hot in some ambient conditions.
From Turbo start, percentage of max brightness where each flashlight settles after stepdowns, in general within 10 minutes after start. I checked these numbers because for the way I use my flashlight (as a walk light, duration ~50 min), where the light settles (the sustained brightness) is most important. Lights that settle at too low level are not good (for me) because then I would have to re-push button, then it would get dim again etc.
1. Convoy Headlamp H2 w/ Nichia 219b: 61%
2. Convoy S21D w/ Nichia 219b and 519a: 37-40%
3. Convoy M21E, F, and B w/ Getian GT-FC40: 35-37%
4. Nitecore MH12S w/ SST40: 33%
5. Fenix Headlamp HM65R-T w/ SST40: 32%
6. Emisar D4V2 with Nichia 219b: 22-26%
7. Wurkkos TS30S w/ SBT90.2: 16%
8. Wurkkos TS21 w/ 60° Max Temp: 16%
9. Coast XPH30R Headlamp: 15%
As some of us have observed, Convoy lights tend to settle at highest level, that’s partly why I love them. All Convoy lights stay bright but the Convoy H2 headlamp with Nichia 219b in particular is fantastic and extremely highly recommended as headlamp for evening walk/exploration (keep in mind it is heavy so you need to buy headstrap with a top strap like Convoy’s own upgrade strap available on Aliexpress, or like this one). The Nitecore MH12S, one of my favorite throw lights, is not bad.
The few Anduril lights that I have tend to settle at the lowest percentage, especially Wurkkos, even after thermal limit has been raised. But note that 16% of the monster SBT90.2 LED in the Wurkkos is still the brightest light in my collection 
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Sorry to interject--I am inclined to think that absolute output in lumens is a more reasonable measure of sustained output than percentage of turbo.
Consider, hypothetically, two lights A and B that are otherwise identical, except that light A can sustain 500 lumens and turbo 1000 lumens, while light B can sustain 1000 lumens and turbo 4000 lumens. You would probably want to choose light B for the purpose of sustained output, even though it has the lower percentage.
No problem - sorry I wasn’t clear. When you see percentage output listed it’s usually because the amateur tester doesn’t have one of those contraptions to measure actual output. Percentage of max output is obtained by ceiling bounce method and I’ve been close when I checked my result against reviews with “real” numbers.
Most of the relevant lights I have have 2000 lm output (2,3,4 and prob 6). There’s actually a 4000 lm in this group, the Wurkkos SBT90.2 monster, and I made a brief note about it.
Ahh I see, that makes a lot of sense. I should not have assumed that you own an integrating sphere ;) (I sure don't!). Percentages that you gave are still extremely useful, as if a user wishes, they could use output from review databases to convert them into lumens.
Yes my integrating sphere is the guest bathroom with a big mirror and no window. Lumen measurements are overrated (said the guy who couldn’t measure lumen :innocent: ); plenty numbers available.
Kidding aside I do use “pro”’s reviews to check my values, like the recent excellent TS30S review by Luxwad. (And conversely, use my measurements to check theirs to make sure no one drops the ball. )
For example Luxwad’s turbo start brightness is 4500, and stepping down to 600-700. My stepdown percentage for my TS30S was 16% using ceiling bounce.
The results with Anduril lights bring me to my next test, to determine whether that final brightness could be higher were I to increase the thermal limit to the max level that Anduril allows, 60 C. The answer is unfortunately, no. Still 16% for Wurkkos. Some other observations:
1. At 60° C, my Anduril lights are still at the bottom as far as sustained brightness. Brightness tends to drop very fast in the first few minutes, off a cliff vs my Convoy and Nitecore that have proprietary UI, at least based on my limited test.
2. Unequivocal evidence that the thermal limit makes a big difference in both prolonged initial brightness AND the final brightness. (Reading reviews of other Anduril flashlights this has not always been clear cut to me.) This is a good sign that Anduril auto regulation is working exactly as intended.
3. When I set Wurkkos and Emisar D4V2 to 60° C max, the external temp as measured by my IR gun is around 50-55° C at the head. What this may imply (meaning I’m speculating) is that the internal temp of Convoy MAY be even higher than the 60 that I’ve measured externally at the head.
4. When I reset my Wurkkos and Emisar to factory setting, the temp read 8 C° and 12 C° respectively, where it should be around 20° C. If I didn’t re-calibrate, then this would bring the max limit to something 10° C higher than set (I hope I’m not losing you here Smile ). Basically this is a way to cheat and increase T max of Anduril . Not recommending, just noting.
5. Next I’m going to Anduril max limit 70° C. Hope nothing will explode on me lol.
Turbo run-down to eventual brightness: ceiling bounce percentage of max brightness that each light settles to after a Turbo start:
1. Convoy Headlamp H2 w/ Nichia 219b 4500k: 61%
2. Convoy S21D w/ Nichia 219b 4500k and 519a: 37-40%
3. Convoy M21E, F, and B w/ Getian GT-FC40: 35-37%
4. Nitecore MH12S w/ SST40: 33%
5. Fenix Headlamp HM65R-T w/ SST40: 32%
6. Emisar D4V2 with Nichia 219b 4500k w/ 70° Tmax : 30% (int temp 64° C, ext temp 59° C, cannot hold w/ bare hand)
7. Emisar D4V2 with Nichia 219b 4500k w/ 60° Tmax : 23%
8. Wurkkos TS21 w/ 70° Tmax: 22%
9. Wurkkos TS21 w/ 60° Tmax: 16%
10. Wurkkos TS30S w/ SBT90.2: 16%
11. Coast XPH30R Headlamp: 15%
12. Emisar D4V2 with Nichia 219b w/ 45° Tmax: 14%
13. Wurkkos TS21 w/ 45° Tmax: 8% 
my poor Wurkkos, at least the LED is a gem
I added numbers for T max set at 70° C. I don’t really recommend this because both the Wurkkos and D4V2 became very hot at Tmax 70° C and no longer could be hand held. External temp at this setting was similar to that of my Convoy lights, 59° C. Internal temp was at least 64° C.
But… note the D4V2 did hit 30%, closer to Convoy’s numbers. Hopefully with a larger host and more efficient driver, external temp would be more acceptable and this percentage would be even higher. Would an Emisar D4K with boost driver be such a light? Finally a worthy (and very pretty) competitor to Convoy S21D, with multiple finishes and numerous Nichia LED choices? Hmmm I’m tempted.
You can get the D4V2 in a boost driver as well. I believe the only difference in the D4K is the battery tube. I'm pretty certain the head is the same size, so dissipation probably won't improve much, regardless of the larger tube.
Would love to see Hank make the head longer, and have more heatsink on it, kinda like the EDC18. With the boost driver, the D4K could be beast of efficiency using a larger head.
Shoot out at the OK corral - Nichia B35AM 4500k vs Getian GT-FC40. I wonder if the B35AM could de-throne GT-FC40 as THE thrower with rosy tint to buy. It’s not going to be easy because GT-FC40 is the great Nichia 219b imitator. Same host so the comparison with COD level beamshots would be interesting.
As usual I don’t need another light, and much prefer integral USB-C charging and side switch but the MAO M21B has an interesting finish and I can’t wait.
I actually attribute this purchase to Tactical Grizzly’s excellent Convoy Guide Grizzly’s Convoy Guide – Grizzly's Reviews . That guide is “trouble” when you have sudden increase in the Emergency Flashlight Fund.
Oh thanks - I didn’t know that about D4K.
The pic below shows how much bigger S21D is vs D4V2.
Yeah a larger D4K would improve thermal stepdown, OTOH I like the small size of Emisar D4 series (just wonderful to hold and feel good in hand), so I actually appreciate Hank keeping D4K size small. Wish if there could be on-board USB C charging though; wonder when he would add that feature to his lights.
New black M21E with GT-FC40 5500k to join its sibling Silver M21E @ 4500k.
I continue to have great interest on this Getian series, because IMvHO LED’s available nowadays more or less fall into one of 2 groups:
1. LED with great color rendition (Nichia), but they are not throwers.
2. LED with great throws (SFT40, SBT90.2, etc.), but CRI ranges from bad to horrible, and green tint ranges from hmm not sure I like that to OMG am throwing up.
The Getian GT-FC40 is AFAIK/IMHO the first, and so far only, LED that has excellent medium-range throw, great CRI, great tint, and beautiful color rendition. Basically they are the prototype all around walk light or every day light for the common man. The one light that I would have if I were to have only one light.
I think the 90CRI XHP70.3 might take the crown from the GT-FC40 based on early reports. There may be a newer generation of the GT-FC40/60 coming soon.
Sounds intriguing. Hasn’t the XHP70.3 commanded a good bit more money than the GT-FC40?
That’s fantastic that it’s released by Convoy (expecting the best bin), and in host with USB C charging. I have hope at the same time that I am very leery of Cree LED’s. The 2 worst green hell I’ve had were XHP35 HI and XHP70.2 Neutral White (70.2 does have amazing output).
There is one review of XHP70.3 I found https://thelitereview.com/flashlights/cyansky-p25-v2-0-review-xhp-70-3-led/
“There are tint shifts throughout the beam profile. The hotspot is cool white whilst the corona possess a yellowish-green tint; and the spill having a slight purple tint.”
Hopefully Convoy’s version will belong to a better bin. OTOH if it’s a super thrower in the class of SBT90.2 all will be forgiven :smiling_imp: as I tolerate green tint a lot more in throwers. Probably will wait for more reviews and release of LED in M21E host for now though (M21F is available but not E, the better thrower).
What about the width of the spill (vs. 21B as well)? Because tighter spill tends to be brighter as well while not being more practical at all.
I hope this picture makes more sense than my writing. The easiest way to see is comparing M21E, which has dim spill, to M21F, with a brighter spill. M21B has the brightest spill. This bright spill means the largest peripheral illumination area (most floody).
WRT to hotspot (representing throw), M21E hotspot is brighter (longer throw), with a clear border between hotspot and spill. I remember Simon refers to big reflector as having “tighter” hotspot.
My personal preference is that for close-up work such as for example touch-up paint of my car, the more floody M21B or M21F is “better.” M21E with the intense hotspot is blinding and illuminates too small of an area. For outdoor purposes, such as evening walk or exploring where I would like to see further away for safety reason, the M21E is “best” and M21B less desirable, with M21F in the middle. But this is just me.
Bright spill means higher light intensity, it doesn’t mean that it’s wider (larger angle). Wide spill can be bright (more intense) or less bright. They are two different things which you’re seem to be using interchangeably. The angle depends on reflector’s ‘width x depth’ ratio and bezel geometry (thick and deep bezel cuts some light).
Very good discussion. I think we are both right, but talking about two different things. If you keep in mind I am describing what I actually see, then hopefully my writing will make more sense.
A light could have a wide measured beam angle, but if that large area of spill is NOT illuminated well, we won’t see that as a wide angle illumination. An example is IF22a with very wide 110° beam angle, but no one will see it as having a large wide spill in actual use. Because in actual use, the wide angle area is poorly illuminated and not seen. Measured angle (fixed) vs actual observation (varied with brightness).
These 3 lights that we are discussing actually have identical beam angle around 80° or so. But as seen in the beamshot below and in actual use, what I wrote still holds true: At any given brightness level, M21F has brightest spill and largest peripheral illumination area (most floody). M21E has dimmest spill and smallest area of peripheral illumination, despite of having the same measured beam angle. Brightness of the spill does affect observed beam angle in actual use. Of course all IMvHO.
