I’m debating a M21B or M21F for my first FC40 light, I like side switches but afraid the larger M21F model isn’t as pocket friendly…
Thoughts?
OT I am not liking the new forum at all. I posted a lot of measured specs on the first post of thread and now on a long thread there is no easy way to jump back to a certain page. Is there?
IMHO the main differences between the 2 lights that affect which one I would pick: 12 groups UI of M21B vs side switch UI of M21F, rear button vs side, USB C charging vs none. I generally would recommend M21F over M21B because the USB-C charging makes it so much more convenient especially if you are going to use light a lot, side button to me is important, and lastly battery check is not a long scary adventure like 12 Groups, but YMMV.
Otherwise these 2 lights are very similar. M21F has slightly (meaning really, not much) better sustained brightness and thermal capacity per my amateur non-rigorous 
testing . The beam profiles are very similar. M21B hotspot a little larger with more blurry border, M21F hotspot more focused IMHO. Not easily noticeable in actual use.
It’s really odd that outside the various Nichia’s, Getian GT-FC40 4500k is the only other brand and only other LED that has great color rendering like a Nichia (closest to 519a 4500k). A very special LED.
Thanks for the great advice!
Do you think the M21F is that much bigger that it would be annoying to put in the pocket compared to the slightly smaller M21B?
I don’t think so. But then I don’t wear those goodness-so-ultra-tight jeans like young people. For “normal” fitting Levi’s and especially Khaki with side pocket, not much of a difference.
Both are bigger than S21D. The head is where the difference is between M21B and M21F. M21F’s diameter is about 4mm larger as seen in picture above. Lengths are same.
The main determinant as to which one to buy for me is side vs rear button, and USB-C charging vs none. Either UI really doesn’t bother me.
Cool, swapped the M21B for the F
In case you’re interested, the Convoy metal clip is functional, beautiful, and dirt cheap 
. It is my most favorite clip and made for S21D and M21B, but does fit M21E and F.
The screws are a little short for M21E & F, but I am mechanical-skill challenged and I could install it.
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Nice collection!
Hi cannga, I need your help)
i read the topic all evening, looked at the photo and could not understand how gt-fс shines, the fact is that I really like how 219b shines, someone wrote that 519a 5700 will be as close as possible to 219b after removing the dome, I ordered Convoy s21d and made him a grandfather, and was disappointed, this is not the right shade at all, I don’t like this clayey or peach shade. There is no such purity as 219b in the world. Right now I’m choosing, will the M21E on GTFC 4000-4500 or 5000-5500 suit me? In your photos of nature, it seems to turn yellow, I don’t want a peach shade, only crystal clear like 219b or very similar, the main thing without yellowness
Or buy s21d again already at 219b, I just would like to be more powerful and with a side button and charging, so I’m looking at GTFC, but I’m afraid that I won’t like the light again. If you have time, you can take comparative photos in nature, and gtfs for 4k and 5k and 219b. What do you think would suit me? )) I’m already tired)
Hello Prophetic219b & welcome to BLF. After all the time wasted with this hobby 
, I have 3 observations:
- Nothing looks like 219b 4500k or makes colors pop like it. But… GT-FC40 comes very close, and IME the only good-output/good-throw LED on market at this point that does so (and actually better than any other Nichia).
- White wall A/B comparison against 219b is the kiss of death. 219b makes all my other LED’s a little yellow or a little green. Don’t do this if you want to be happy LOL.
- Nature shots are more “reliable” than white wall beamshots for testing whether I’m going to like a LED.
IMHO Getian GT-FC40’s tint is in between 519a 4500k (“sunset yellow”) and 219b 4500k (rosy/magenta), but closer to 519a 4500k than to 219b.
GT-FC40 vs 219b: The 2 shots with question marks on left side of picture below, could you tell which one is GT-FC40 4500k and which one is 219b 4500k? (I had trouble at first.) Not too bad of a Nichia imitator I think, and we don’t have any other choice anyway.
thanks for the answer, buddy, of course, the top left one is unsurpassed 219b)) I have been choosing and thinking all day today, I decided to take 219b, now I’m thinking in which building. I like the blue Pineman K27, but 1100 lumens is not enough of course, and the s21d has 4 diodes, but the view is boring and there is no charging port with a button, now I have a crazy idea how to decorate it, maybe paint some details in the color I need from a spray can: D honestly I was looking for how to diversify the lantern, I came across a reddit on a person who paints them, https://www.reddit.com/user/JNader56/submitted/ but it is not known how long it will last, I want to repeat and check)) while I think above the lantern. It’s good that I already decided on the diode, thank you.
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Correct answer as expected and seems like you got the 219b addiction alright 
. But yes AFAIK if you want Nichia with throw and 2000 lm from a single LED, GT-FC40 4500k (NOT 5500k version) is the only choice. There is this new Nichia 719a that Simon is testing but I don’t know what it will look like.
I enjoy more colors also and have used spray paint (left over from touch up painting of brake of my car, hence yellow) but so far only on the clip. Problem is if you use the flashlight a lot, the paint starts to come off, at least with the simple amateur way I am spraying it. And for me paint just cannot match the beauty of colored anodizing. The MAO M21B with yellow stripes on clip is my favorite combination at this point.
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If you legit want a nice 4500k 519a, your best bet is to dedome a 5700k.
I like M21E with GT-FC40 so much (Nichia-like tint with better throw and output - IMHO best overall gift light, everyday light, etc.) that I bought a second M21E from Convoy last month. Unfortunately, this second light has greenish beam color that is noticeably and significantly different from my other 3 Convoy lights with the same GT-FC40 4500k LED that were bought in 2022. A forum member had mentioned this tint lottery problem with this LED to me in the past, and now I could confirm it with first hand experience.
Repeat measurements using same Opple Light Master:
First batch M21E GT-FC40 4000-4500k: Ra ~ 98, Duv -0.0040
Second batch M21E GT-FC40 4000-4500k: Ra ~ 92, Duv +0.0020
First batch was bought when light just came out in March 2022. Second batch bought September 2024.
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Beam shot of my 5 Convoys with GT-FC40. I like M21E with GT-FC40 so much that I bought a second one this year. This newest one looks visibly green 
. I know the beam looks yellow but in real life it is green.
All pictures shot in RAW w/ Canon SLR and WB at 5000k.
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Proof of the dictum “things could always be worse”? I added a light with low CRI XHP 70.2 to show a LED that shows true green.
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I took the black-sheep GT-FC40 light for my walk last night, and would now correct myself that in real life and in comparison it is more of a yellow, not green, tinted GT-FC40, made obvious next to the Sofirn’s green XHP.
Of course we don’t have a large number of samples to know how common this tint lottery problem is, whether it is one in a latter batch or all of the latter batch. It really is too bad because a good GT-FC40 4500k is IMHO/IME a fantastic and very unique LED: a Nichia 219b 4500k imitator , with better throw and vastly more output (2000 lm GT-FC40, 600 lm 219b in Convoy H2). If you have one of these good samples, hold on to it like dear life.
Mine definitely seemed yellow but looked green against the rosy ones.
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The tint lottery w/ Convoy GT-FC40 4500k is quite disappointing; just don’t know whether it’s just my M21E, or the whole batch. The good news is the two Fireflies I ordered (X1L Elite on sale 30% off ), are here in LA. Both supposedly have beautiful and unusual LEDs, and both supposedly “thrower with good CRI and great tint”. I am so impressed with my E07X-FFL351A’s rosy tint and overall excellent quality that I decided to take a chance with other FFL LEDs and lights. We’ll see soon enough.
X1L Elite - Fossil Grey MAO / FFL707A 5000K NW CRI95 3200LM 65kcd
E04 Surge - Navy Blue / FFL505A 3500K CRI95 3200lm 480m (Rosy)
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Could it be wrong emitter installed with a different temperature? Yes on the picture it looks very yellow
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Good point (more importantly, not just picture, IRL it looks completely green-yellow). Needless to say, the green light has been dissected and measured multiple times. CCT 4000k (claimed spec 4000-4500k) Duv about +0.0020. The box’s label says it is the “correct” LED. I have 5 other lights with same LED, measured with same Opple (I have two Opple 3), Duv all negative about -0.0030 to -0.0050. CCT’s however are ALL a little higher 4400k-4500k. It’s as if they came from a different batch.
About a year ago, someone who is also a tint snob (best sense of the word to save explanation) with multiple lights emailed me with the same problem. Yellow green beam with same LED. We were both so puzzled and finally decided to check with Simon to confirm AND for him to get Opple LM3 (great for him because LM3 is no longer available). The positive Duv also confirmed. Correct LED also confirmed.
Actually at that same time frame, IIRC someone was complained of the same tint problem on Simon thread. Nevertheless, the reports are still anecdotal (vs. tint lottery is nothing new). Unless I ordered say 100 lights from Simon, nothing is conclusive. I am hoping to hear more from owners who recently ordered the same LED (btw, don’t bother with 5000k version, ok but whitish/sterile & not impressive to my eyes).
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