This next observation is only for the hard-core pixel peepers among us , in case you missed it the first time around. In real use, I’ve noticed Nichia 519a always seems to be brighter than 219b. From the 2 pictures below, it appears it’s not the central area of 519a that’s brighter, but it’s the periphery, the “spill” area (in parenthesis because these S21D’s are very floody and don’t really have hotspot and spill per se).
I don’t understand why this is so since the optics are the same. Both are domed LED of the same size no? Anyone would like to explain?
The die sizes (area of light-emitting surface) are different. The 219B die is a bit over 2mm^2, while the 519A die is around 4mm^2. With a larger die, you can expect a greater percentage of the output to become "spill" rather than "throw".
Thank you for explanation - now it makes sense. The two LED’s are so similar visually (1.5 mm vs 2 mm each side) I did not take into account once you square that seemingly similar size, the area is actually almost twice as big.
For me a must-have for the 12-Groups Convoy UI as it makes both “click” (full press) and “tap” (half press) so much easier to engage. Especially the half press since there is a now a “built-in” FIRM stop at half press, the fixed outer metal ring.
They could tail stand but it’s not stable, especially for the bigger M21B. For example on a heavy dresser is OK but table probably not. A side hit on the table will make them fall.
White wall shot showing difference in illumination between 519a and 219b in Convoy S21D. This was taken about 2 minute into a run-down from Turbo. No ventilation was provided. Taken with Canon DSLR in RAW format, 5000k white balance.
In addition, the difference in beam tint between 519a and 219b is pretty obvious. Both being Nichia, maybe I did not expect such significant change but “vive la difference” .
BTW specs from Convoy - Flux: max 2000LM (219B) / 2600LM (519A)
I have new toys for the S21D twins: clear optic from IF25a that could be used in place of Convoy’s stock frosted optic. Brighter hotspot, less spill: It should make the light more useful for my evening walk, especially for the floody and bright 519a.
The IF25a optic’s diameter is very slightly smaller than stock, but still fit without any problem as the posts are in the same spot and height identical. The LEDS are still in center of each optic (9 mm center to center). Where to buy - 69 cents each : Quad Optic Lens for IF25A
I measured 2055lm for the 519A in the S21D on 100% (stepped down to 790lm between 105secs and 10mins), and 860lm on 35%, which is pretty good for the lights size and 95CRI. Convoy tend to quote theoretical lumens.
I sure will. Prelim result is excellent; as expected dimmer spill, but brighter central area. The stock S21D is nicely floody, but a bit too much for my use. The clear optic makes it a little more balanced with some spill + some throw. The Convoy now behaves more like Emisar D4V2.
The frosted optic makes for a nicer smoother white wall shot (probably one reason why it’s used, for the sake of perfect users’ reviews ), but in actual use the clear optic is “better” for me because it increases max brightness (albeit in central area only). Any increase in max brightness is always a plus for Nichia lights for me.
At 69 cents IMHO this is a no brainer rec. for owners to try and decide for yourself.
@cannga - I tested my S21D (w/ 219b emitters) with the IF25A optic. For me, this is a major improvement. It gives a truly defined hotspot and makes it much better for general purpose use. I appreciate you doing the research on this and sharing your findings, as I’m very pleased with the results.
Strangely enough, I think I prefer my IF25A with the optic that came with the S21D, so it’s a win/win. Are you aware of any other optics that fit these two lights?
On a different note, have you noticed any strangeness on your S21D in terms of brightness? I’ve tested two groups (#1 and #5), and the 100% on both is NOT max brightness. If I cycle through the levels, every now and then it will jump to what I would refer to as “turbo”. The easy way to tell, aside from the increased brightness, is that at 100% the light head does not heat up to uncomfortable temperatures even after 10 minutes of running. At the “hidden” turbo setting it gets rather hot after <1 minute. The light does not remember this setting after turning it off - it reverts to whichever setting it was on before you slipped into “turbo” and you have to fiddle with it to get it back there.
I would describe the perceived brightness difference between “100%” and “turbo” as roughly 2x. It’s very noticeable. It seems to be easiest to get into this mode by holding the button in just before the amount of pressure normally required to cycle modes, then releasing once it switches to “turbo”. I have run it at this setting to the point of it getting as hot as my single LED Convoys get (not too hot to touch, but getting uncomfortable) and it has not released the magic smoke.
@undefined - I can’t say that I’ve seen any abnormality with the brightness. Not sure what is going on with yours but just a couple suggestions:
1. Turn memory off to remove that from the equation. Does the flashlight still have problem?
2. I use group 6 with memory off. Maybe gives this a try? It should turn on at max 100% every time and there should not be any brighter level. I will try your maneuver later to see if I could reproduce the “100 PLUS” brightness. Hope this helps.
Btw credit for the IF25a clear optic goes to poster “Verodin,” and yeah I am not going back to frosted optic.
I tested the hidden turbo out with my other S21D. I put it in group 12 (100% only). Turn it on, then hold button and it jumps to much higher brightness and stays there. Turn it off and back on and it returns to “normal” 100%.
Two different S21D, same odd behavior. One is 519a, the other is 219b.
1. Set light to group 12 (the one that has only one power level, 100%).
2. Turn light off and then back on. Verify that half press does not engage other illumination levels.
3. Hold button in, not as far as a normal half press. This may take a few tries, but you’ll know when you’ve got it as the light will get noticeably brighter. When you release the button, the higher brightness level will remain.
4. When you turn it off and back on again, it will return to normal brightness level.
The 519a does this with almost 100% reliability. The 219b I have in mode 6, it takes a lot of tries in that mode to make this happen. I may try to change it to mode 12 later and see if it behaves the same as the 519a, I just hate changing mode groups on the Convoy driver… 20 clicks is too many, Simon!
If you’d like, I can try to record video of this.
Also, finally have both versions (219 and 519) of the S21D…. definitely like the 219b better.
Please note my two S21D’s have the metal switch, not the stock rubber switch. I tried the above maneuver with 519a in Group 12 setting and cannot reproduce the “100% Plus” mode. Tried the 219b in Group 6 setting and cannot reproduce it either.
, in case you missed it the first time around. In real use, I’ve noticed Nichia 519a always seems to be brighter than 219b. From the 2 pictures below, it appears it’s not the central area of 519a that’s brighter, but it’s the periphery, the “spill” area (in parenthesis because these S21D’s are very floody and don’t really have hotspot and spill per se).
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