Convoy S21D w/ legendary Nichia 219b :) - Review & comparison w/ Nichia 519a, E21a & other lights with Nichia LEDs incl. Emisar D4V2, Convoy S21F. (Summary & measurements on P. 1)

Sorry for OT, but every time i see a MAO flashlight i think about them!

Specs from Simon - even among these top Nichia LED’s, the B35AM’s CRI numbers look exceptional. It has among the very highest Ra and R9 numbers that I have seen. Duv on negative side, hopefully beam color will be different from what I’ve already had, to bring variety to (flashlight) life.

Throw of B35AM in M21B host is 263 m, instantly making it the most throwy-throwish small Nichia light I have (S21D and Emisar D4V2 with 219b 4500k are next best at ~170m see here). This is equal to GT-FC40 4500k’s throw in same host. However there is more to this story, as output of B35AM is roughly half of FC40 by my amateur ceiling bounce method, so something has got to give (area of central brightness and spill).

Now that I actually see the MAO finish, I think it is very beautiful. It’s a fantastic subdued off white, almost chalk white. So different from every other flashlight I have. @Argo see pics of the stormtrooper’s head and leg :slight_smile: . Anyway, my preliminary thought: from what I see so far, IMHO get your money ready (grin) if you’re into collecting Nichia.

Nichia 219b 4500k
CCT 4526k
Ra 96
R9 97
R12 79
Duv –0.00995

Nichia 519a 4500k
CCT 4500k
Ra 93.6
R9 82
R12 80
Duv 0.00091

Nichia B35AM 4500k
CCT 4454k
Ra 98
R9 99
R12 77
Duv –0.00503

I like it too… I hope it proves suitably durable for you

Storm Trooper Edition… lol

Can anyone confirm that s21d fits wurkkos 20350 tube? I know s21d shares threads with s21b, and that the s21b fits the wurkkos 20350 tube and works, but if possible anyone has the combo and post wether or not it works? I’d like to see how it looks like too.

There must be something wrong with yours then because B35AM should produce about 1400-1500lm at 2,4A. There were issues with burning LEDs at 3A that’s why Simon dialed it down. Maybe yours was affected as well?

Although I take a lot of white wall beamshots, I refrain from commenting until I have seen it in actual “real life” use. So last night I had Skilhunt on my forehead, and 3 lights (D4V2, S21D, M21B) in my pockets. It’s a good thing my wife is used to this craziness. :person_facepalming: :slight_smile:

Beam color: Used at high and medium mode during my evening walk, B35AM 4500k appears to be in between 219b and 519a 4500k, but is closer to 219b’s magenta/rosy tint than 519a’s neutral tint. For those who find 219b at times just too rosy, B35AM would provide a relief.

Beam character: A bright and relatively smaller hotspot (small, not tiny), and spill that is of low-medium brightness, but still bright enough to make it useful as a walk light. The throw (~263 m vs ~170 m) is subjectively significantly better than my S21D and D4V2. For me this is the first Nichia light in my small collection that qualifies as a walk light.

Beam Color Comparison: Comparison of LEDs in different hosts is inherently difficult; as a result the exposure setting of pics below are not the same. I adjust so they best approximate what I see in real life; meaning very subjective.

At this level all 4 LEDS are excellent in reproducing colors. They do have different tints (rosy vs neutral) and which one you like comes down to personal preference, if you like the famous rosy/magenta tint, then only 219b 4500k would do. If you prefer a neutral tint, then it is 519a 4500k with what I see as a “golden” tint. In between those 2 bookends, there are the B35AM and GT-FC40. Some comments based on “real life” view:

Nichia 219b 4500k: That famous rosy/magenta tint. In actual use in nature scenes, both GT-FC40 4500k and (even more so) Nichia B35AM resemble this LED.

Nichia 519a 4500k: Neutral tint, “golden” color (more yellow) to my eyes.

Nichia B35AM 4500k: My nick name for B35AM: “219b with throw” IMHO. If the magenta tint of 219b 4500k is too much for you, then this should provide some relief, if only a little. B35AM still leans much more towards 219b’s magenta than the neutral tint of 519a though. There are two LEDs in my collection that look like 219b: first is E21a, and second is this one, B35AM.

Getian GT-FC40 4500k: Still looks like 219b overall, but now surely leans more towards the golden tint of 519a.

B35AM may produce 1400lm but that would be 70cri 5000k on super good mcpcb and without losses on optics etc.
Convoy’s b35am 4500 r9080 will never give you 1400lm, they will fry much earlier.

I talk about real lumens in real flashlight s21a/b with 3A driver. And it give you just 1000lm on 3A. Datasheet tells the same - 1400ma and 700lm for convoy’s bin. You may find actual tests or measure it yourself.

It will give over 1400lm:

R9080 (high CRI), E800 (which is exactly what Convoy uses) produces around 1250lm at 2A, 1400lm at 2,25A, a touch over 1500lm at 2,5A, it should produce ~1750lm at 3A unless it fries itself. Simon reduced the drive current from 3A to 2,4A in order to avoid the latter.

We’re talking about around ~1450 emitter lumens. GT-FC40 driven at 2,5A (12V so essentially double the power) - 2600 emitter lumens. 519A at 6A (3V) - ~1250lm. Those drive currents are what Convoy uses in M21B:

I know this graph. In convoy it’ll be a ‘little’ different result. But once again - if you take real convoy flashlight and measure it - no way you will get 1400lm with its b35am. You operare with theory not practice.
Measure it yourself or open testing results of s21a/b b35am.

You may not trust me and belive that u get 1500lm.

As I said those are emitter lumens, before optical losses but they’re like 15-20, not 40. Most reviews of Convoys with B35AM are pretty old when the LED was overheating. Also newer ones have different drivers where S21A pushes just 2,2A into the emitter which is less than in M21B.

But still it should produce almost 200lm more than 519A and at 2,4A it shouldn’t fry itself.

Thanks guys for the interesting discussion. The graph that @phantom23 was referring to (the red curve):

Yes, those are emitter lumens before optical losses.

Observation from “real life” (not white wall hunting) use:

The M21B w/ B35AM is the coolest running Convoy flashlight I have, by a wide margin, clocking in at 42° C after 30 minutes continuous on from a Turbo start at home. In actual use (Turbo start then leave light alone during my walk), the S21D w/ Nichia 219b becomes almost/kinda too hot to hold in current LA weather, M21F is second, a little cooler but still quite hot, but M21B is acting as if it’s just loafing around.

Even more surprising, it is THE coolest running flashlight I have including other brands. At 42° C it acts as if it’s running at half throttle. I almost wish for a higher voltage (edit: current, thanks phantom23) than 2.4 A but I understand bad things did happen at higher current so unfortunately that won’t happen.

Allow me to post another picture of this very pretty light, together with my other latest Convoy light, M21E with Getian GT-FC40 at higher CCT 5500k. It is EXACTLY the light I have been looking for, a Nichia with throw and I recommend extremely highly (I love it).

B35AM may appear to run cool but partially that’s because of poor thermap transfer (that’s why Simon had to reduce current from 3A to 2,4A - emitters were frying).

Of course you meant higher current.

Yes of course thanks, current. :+1:

Questions please: Why would it have poorer thermal transfer than say GT-FC40 in same M21B host (ie same design)? My GT-FC40 in M21B stays at 60° C.

Also this is a 30 minute run so the thermal transfer can’t be that poor, can it? Wouldn’t it fry the electronics if all that heat does not escape after 30 min?

Poor heat transfer between the emitter and PCB. There are no dedicated PCBs for B35AM, flashlight manufacturers need to improvise but thtere’s no good solution as of yet. So yeah, the emitter itself is hot it just transfers less heat to the body. That’s one thing. At 2,4A it uses 50% less energy than GT-FC40 so it has to run cooler.

If you determine the Actual Sustained Lumen output of each light, and its weight, you can calculate lumens per gram.

the coolest running light probably has the lowest Lumens per Gram.

@cannga: what is the ambient room temperature when you did the tests? The equilibrium temperature of a running flashlight depends heavily on both amount of power dissipated by the light AND the ambient temperature--leaving out the latter makes it impossible for us to deduce how much an identical light would heat up in our usage, as our ambient temp might differ much from yours.

It’s good you’re taking an interest in this. Nothing unusual 70-75 F. But let me rerun the test with all 4 lights (M21B with B35AM and FC40, M21E and M21F with FC40) in same condition tonight just to make sure I haven’t screwed up somewhere.

Are you thinking convection heat transfer also as a method to check what the temp inside is? Would shooting at the lens provide a clue also for internal temp? I will also take the lens off and check the LED, but it might too hot (upper limit of my IR gun is 60 C).