GT-FC40 datasheet? 3000K beamshots?

I’m set on purchasing a GT-FC40 light and initially chose 4000-4500K, but I’ve recently grown to love warmer CCTs after using my 219B SW30 a lot (and owning too many 4500K lights). I’ve seen third-party tests on the 4000-4500K - but none on the 3000K-3200K so far. Can’t even find a datasheet of the thing.

My real question would be - how good is the DUV throughout varying power levels? The 4000K version dips ever so slightly below the BBL at high power and has very low positive values at lower power settings - if the 3000K version does the same then it’ll be in the next M21B I order. Maybe even that new FC40 that Simon’s teasing in 1800-2000K.

TL;DR I hate green in my lights.

Been looking for the datasheet as well, but nothing. Closest I could find was GT-FC35 on Getian’s website, but that’s a totally different LED. Same on another Getian website

Have a 3000-3200K M21B incoming, should arrive this week. Maybe someone else already has one and sees this topic beforehand, but otherwise I can do some quick testing this weekend earliest. I don’t have testing equipment to give exact numbers though.

I’ve seen one post online that compares the beams of the FC40 in 3000K and 4000K beside a 219B from Reddit user IdonJuanTatalya: https://www.reddit.com/r/flashlight/comments/rdj7j7/mmmmm_toasty_gtfc40_3000k_219b_sw35_gtfc40_4000k/

But his 3000K already has different optics from the default M21B. No CRI/output/tailcap amp tests, but it certainly influenced me towards getting a 3000K GT-FC40 instead of a 4000K. I love how warm that beam looks, hopefully no sickly green in the hotspot with the M21B optics.

I’d love to see your beamshots Verodin, throw and CRI numbers are nice to have but I find beamshots and real-life use sells the flashlights more than pure numbers alone. For me, at least.

Same here. Initially I went by the numbers and quite quickly discovered that can end in disappointed. The only number I do look at is CRI. But the rest is very depended on personal preference and many other factors. When I see beamshots in reviews, it often shows how usable the throw/flood of a particular flashlight actually is. Sometimes also how clean the beam is (but here white wallshots take the cake, e.g. eggy beam or not). And it also depends a lot on what you’ll be using it for. I’ve found that high CRI neutral tints are great for close up accurate work (think puzzles), but they can feel dead when used outside or in a forest. No matter how good the numbers look on paper. Something less neutral can make it come to life more. And even then it’s still hard to get it right.

Really hope the M21B arrives today or tomorrow. It’s in the country, but the postal service has been slow lately due to staff shortages (probably corona taking its toll there).

It finally arrived… woohoo :slight_smile:

Waiting for it to get dark, but did a quick comparison with 2 other flashlights. Closest temperatures I have are a FC11 2700K and S2+ 3500K, both LH351D emitter. Camera WB set to daylight.

From left, up, right: FC11, M21B, S2+ and all at lowest brightness I could compare at to draw out any green. The 3500K LH351D is most definitely green in this comparison. 2nd photo at full brightness, the FC40 leaves the other 2 bite the dust. 3rd photo I had to set to S2+ higher to make it more fair in brightness.


1st impression is good. The GT-FC40 seems to keep tint pretty good across all brightness levels and I can’t detect any green in there. But like I said it’s a very quick test, so preliminary result.

I plan on going outside once it’s dark. Anything specific you want me to do?

An attempt at showing something that hopefully remotely resembles a CRI test without having a dedicated tool. Maybe a bit crappy, but I picked the spot because there’s red and blue in there (e.g. something that resembles R9 and R12). Very different temperatures, don’t know how much value to attach to these shots.

M21B FC40 (unspecified high CRI)

IF25A with SST20 (4000K CRI 95)

IF22 SFT40 (5700K? low CRI)

And some random shots around the place. Ignore the mess, winter is not over yet and the snow (that recently melted) and winds have taken their toll.




Great shots. Interesting to me, as I recently received a Pioneman K36 in XHP70.2 3000K. Here’s a “white wall” shot from about a meter for comparison. WB set at 5000K on my S10+.

Received a Hank package today, so thought it would be nice to add another comparison.

S2+ LH351D 3500K vs M21B FC40 3000-3200K vs KR4 E21 3500K

B35AM 2700K vs M21B FC40 3000-3200K vs KR4 E21 3500K

Really need to get some other 3000K emitters… Got too many 2700K, some 3500K, but basically nothing in between…

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Great beamshots! I’d like to recommend a 219B SW30, love this emitter but it’s all tint and CRI and lacks the output that newer LEDs now have. Convoy’s SW30 looks great across all power levels, unlike the SW35 and SW45 they carry. I’m liking the FC40 3000K, light looks clean. I’ve also considered getting E21s but the output is too low for my liking. I’m interested in the B35AM light - which host is it in? I have a B35AM in 4500K that I enjoy using and I’d love to find a light with a warmer B35AM. The Samsung isn’t that bad, but that high DUV is really obvious.

Thanks for the share Verodin! Looks like going for a 2700K FC40 is gonna be fun - but that warm B35AM has really caught my attention!

Glad to hear it’s useful :smiley: The B35AM is a Noctigon DM11 host. Just had it a few days, still building an opinion concerning the emitter in that host, it’s a different experience being a warm mid range thrower. Really starting to enjoy it though. Also have the 4500K in a Convoy S21B (floody). So very different visually compared to the warm ones. But they all look clean, which is satisfying.

The E21 is very nice as well, but like you pointed out, it’s low output. Great indoor, less useful outdoor.

I ordered those 3 versions of the 219B a while ago, really want to try them. Should arrive next week. Also already have a bare B35AM 3000K and 3500K waiting to be soldered. Still waiting for a hotplate though. Was too late with it, so CNY got in the way. For the 219Bs I’m thinking of trying with hot air or the iron from underneat the mcpcb. But the B35AM is too expensive to mess around with on a 1st attempt.

Btw, while digging through the massive Convoy thread I found this post by Simon

FC40 3000-3200K

Disappointingly low R9 and R12 for a supposedly high CRI LED. There the Nichias and E21s do much better. But the FC40 is way more powerful, so it’s an acceptable compromise imho. Maybe a fairer comparison would be FC40 vs Cree and the FC40 eats Cree eggs for breakfast :smiley:

PS, seem to vaguely remember a photo of Simon’s measuring device while measuring a 3300K FC40. Can’t find it at the moment.

PPS, in case you’re into the 1800-2000K FC40; Simon posted measurements

I believe it was one of these Hopoocolor models: https://www.aliexpress.com/store/group/Portable-spectrometer/5435348_1000000404726.html

Store home link if that one doesn’t work for you: https://www.aliexpress.com/store/5435348

Ooof, pricey.

But that’s not what I meant. English is not my native language, so forgive me. I didn’t mean the Hopoocolor. Simon sometimes posts photos of his measurements, where he takes a photo of the screen of the device while it’s lying on his desk or holding it in his hand. Like the one in my previous post

I wondered about that as I posted the links…no worries. :slight_smile: Actually, though, seeing his unit in a photo again was helpful because I was wondering exactly which model he chose. They have several and the price goes way up from the base 350C. He’s got the 350S which is the same thing but includes the pc software feature. Seems like their other portable ones aren’t any more benefit for flashlight use as all we need is included in the base model. I’ve been toying with the idea of buying one. The Opple is comparative junk, imho, but it’s sure getting exposure in comments and even “pro” reviews now, which I’m not sure is good for our hobby really.

Got a delivery today with some Convoy 219b emitters. So SW30 comparison time. Quick mod since I only had 20mm a mcpcb and S21A with smooth reflector available for test. I have no opinion yet, but you can see a clear tint difference.


Disclaimer; both not at full power. Went a bit careful with the 219b since it’s driven by a 6A driver that was originally for a SFT40… temporary hack

Sad to hear the low R9/12 values, but I still got one on the way heh! It’s still better spec-wise than other mixed throw/flood emitters that I know of, and I’ve grown allergic to non-high CRI lights.

SW30… the emitter that started my love for warm CCTs. I use one daily, probably the most used light in my stable. I’m looking for a suitable Anduril host with an easy PCB swap to a 219B SW30 since I don’t want to mess with reflowing, considered using an FC40 LED but it wouldn’t be the most efficient use of this large 7070 emitter! I’d love a small super warm light for candle mode :slight_smile:

Hopefully I’ll be able to share some beamshots when my FC40 3000K arrives to compare to my 219B SW30/SW35/SW45s. I’m itching to test out something warmer now that Simon has 1800K FC40 emitters available! Ra94.1 R9 68 R12 93 DUV 0.00388 - not bad! Now for those beamshots… :slight_smile:

The thing is, the FC40 just has so much more power than the Nichias that I find myself using it almost daily. It might not be perfect, but it’s by far the best alternative I have in 3000K. Just a quick scan of the forest edge around the house, 25 - 30m away. The Nichias just don’t cut through the trees the same way. If there are any deer or elk lurking around, they pop up. They love to chew on flowerbuds and fruittree bark this time of year and a quick scan with a flashlight is usually enough to send them on their way. Once I get the 3000K and 3500K B35AM emitters up and running, flashlight choice might change though. And maybe a 519a sw30 will become easily available at some point. That might be reduce the difference in output. The quest for the perfect 3000K emitter is far from over :wink:

By now I’ve also had the chance to try all 3 219Bs and do some basic comparisons. All 3 come from Simon. My observations so far: the sw45 is very magenta. It’s nice, but I won’t be putting it in too many light, simply because it’s not neutral at all. The sw35 is good, I like it. The sw30 is also good, but like the sw45 not neutral. But unlike the sw45, I quite like the rosiness of the sw30. I’ll definitely be performing some emitter swaps with this one (and the sw35).

One strange effect I’ve observed is that when using the FC40 and sw30 at the same time, neither looks good. It just doesn’t compute. It’s been snowing here and nothing, and I mean NOTHING looks white when both are on at the same time. Use only 1 of them and it and your eyes quickly adjust. Never noticed this effect so extreme with other emitters.

PS, if you know any decent 12V Anduril driver that can be used with the FC40, I’d love to know. Simon is working on some models with side switch control, but I prefer Anduril. Especially low brightness with the 2000K one!

I can’t say I know of one, but I’ve also been searching for high CRI warm CCT lights with Anduril and I’ve yet to find one that’s not custom. My M21B arrived over a week ago but I haven’t put it through its paces - until tonight. It’s nearly perfect as a warm CCT light, I agree. It just gets too hot if you like running your lights on high or turbo for long periods of time, but for my purposes of walking my dog on the beach at night or the occasional turtle conservation efforts - it fits my needs nearly perfectly. I wouldn’t mind getting all the neutral and warm FC40 CCTs Simon offers, but I do want some options with the host. Good thing he’s testing some M21x prototypes for the FC40! I can’t wait to get some more of these emitters, they really fill the gap in between dedicated throwers and flooders!

I really just wish we had more lights with these emitters with more advanced UI. With Anduril 2 there really is no excuse to not use them on everything.

Trying out my Opple on the M21B GT-FC40 3000-3200K:

The Opple isn't the best out there, but it does give you a good idea of what your light is putting out. With the CCTs so low I barely see any green, but there is a lot of yellow as this is a very warm light. I'd even call it golden, with a DUV close to the sun's so it always feels like sunset. I love it.

I’d like to think of a sunset when going outside when there’s snow and ice all over the place. No turtles here though :sunglasses:

Nice with the Opple. A bit surprised at the 3375K considering it’s supposed to be in the range 3000-3200K.

Hosts are indeed a problem at this point in time. But that will improve soon with the M21x models indeed. From what I’ve seen most are pretty throwy, but I’m very tempted by the M21D (or the tail button only M21C). The M21C apparently has a 60 degree beam and that might be perfect (assuming M21D will use the same reflector). Also the biggest size and weight of the upcoming models though. I have a L6 and it’s fantastic with the GT FC40 (4000-4500K). But very bulky and heavy. So I ended up with 3 M21Bs; the 3000-3200K FC40 seen above, a 1800-2000K FC40 arriving next week and B35AM is instant buy once Simon gets a suitable reflector with smaller hole in production. I’m really liking that model size and beam wise. Plus they’re pretty portable while having decent heat sinking for the size (wintertime). Downside is they’re only available in black. So I ordered a set of coloured tailcaps to tell them apart. Didn’t feel like putting stickers on them.

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