Yes, basically more metal to heat up, and radiate heat. A good flashlight needs to be able to transfer heat from the LED and driver to the outside shell/host with good thermal pathways, otherwise the thermal mass won’t help much.
Olight M2R Pro Warrior was a popular thrower with great reviews, its beam perfectly designed/shaped with TIR optics for use in my evening walk: large, bright central hotspot to provide excellent illumination far field, dim spill but very floody (wide angle) to illuminate near field just enough.
The limited edition of these M2R’s uses Cree XHP35 HI (flat) LED, which has a lower, warmer CCT of around 4900k compared to the regular version. It is therefore one of the very few EDC throwers with a warm beam. The lower CCT enhances depth and color, as opposed to my Nitecore MH12S with its very cold, very blue 6500k CCT.
Olight M2R was my most favorite walk light, then the Convoy GT-FC40 triplets came and showed just how green the beam color is 
. This is unfortunately something that I can’t un-see.
Just took my first evening walk with my new M21F GT-FC40 4500k. I immediately applied some DC Fix (as I always tend to do) and it proved to be a very nice experience. Not as bright as my TC20 V2, but I wasn’t expecting it to be.
Since I applied the DC Fix almost immediately I can’t say much about the performance without, but with it applied it is a fantastic blend of throw and flood. Tint and color rendering are superb, brightness is more than adequate on 35%, and heat is well managed at that level.
The light handles very well, although the complaints about the recessed button being hard to locate and easily confused with the charging cover are well founded. The light is deceptively long, longer even than my Thrunite Catapult V6, but it’s relatively thin handle and good balance make it very comfortable to use for an extended period. The UI still has its rough spots, but overall I’m very happy with it.
Of course the value here is incredible. $37 for this light plus the included 21700 is fantastic. If you can live with the UI quirks, I highly recommend it.
Good points. This latest (?) Convoy UI for the M21F and M21E, for me anyway, is still not a match for Anduril. But it at least is moving in the right direction versus the 12 Groups of M21B. Battery level is now directly accessed with 5 clicks. BUT… the 5 clicks have to be fast, too fast for me so I missed it a lot of times - do you have same problem? I don’t know whether the problem is with the feel of this particular button (it’s not as light or as easy as with my all time favorite - Sofirn IF25a’s) or with the firmware, but it’s really hard so far for me. I found Anduril’s 3 click to battery so much easier to access.
I found the clip to be a must for these lights to not confuse power button with the USB charging port and also to quickly “blind-locate” the button. I took picture below to show decision-process for clip-on versus screw-on clip for potential buyers. Hope it makes sense 
. (The screw-on clip is MUCH better to use and in appearance.)
It would be a pretty simple matter to drill your tail cap on the E…just position them accurately. Plenty of meat to do so without worrying about pullout from tension/use.
Thanks for the suggestion. Have to stay with clip-on because I am on the clumsy side as a handyman and me taking a drill to this beautiful light would honestly be like watching Death Wish 3 :person_facepalming: 
.
Same Olight M2R pictured above versus M21B, now illuminating a real scene, my front garden. Shots of throwy lights are difficult, as sometimes (as in this case) part of the scene is in the hotspot, and part in the very faint spill. I tried my best to adjust expo so it doesn’t favor one light or another. As usual, pictures taken in RAW format with Canon DSLR, white balance 5000k.
At any rate, GT-FC40 has remarkable ability to render colors as seen in real life: from lavender plant left front, to the brown bark of the tree in the back. In fact when it comes to a light brown surface area such as frequently seen in gardens and nature trails, I actually prefer GT-FC40 over Nichia 219b. The very strong magenta tint of 219b could be a bit too much at times.
My beloved M2R is not as beloved anymore lol. Actually in real life the green tint is not that bad, as long as you don’t do back to back comparison. But here you could see how overwhelming and “destructive” that green tint is. When even garden rocks look green you know your LED is in trouble.
Comparison with a Cree LED is easy - some are infamous for a horrible green tint and unfortunately my XHP35 HI 4900k is a victim. Another one that I’ve experienced is XHP70 Neutral White in Thrunite T2, which was a true green hell .
It is the gold standard Nichia that for me makes the most interesting & tough comparison for the GT-FC40, and next up is the very well known 519a, here in 4500k guise. I was so excited when I placed the order - what not to like about a new Convoy with Nichia. At any rate, 519a has spectacular Ra and R9 (in the LED used by Convoy Ra 93.6, R9 82, R12 80, Duv 0.00091 ), but does have a yellow/golden tint, reflected by its positive Duv.
I still love my Convoy with 519a a lot (the same way people like a variety of chocolate ), but the yellow tint while not nearly as bad as XHP35 HI does seem to show up in A:B comparison, more subtle but there nevertheless. To my eyes, rock and bark of tree take on a yellow tint, more yellowish than live view. All pastel/light color subjects such as the leaves of the lavender plant take on a slight yellow tint. Probably as a consequence, subjects don’t stand out from each other (color “pop” in photography), as seen with either Nichia 219b or Getian GT-FC40.
I was about to ask this. Need to be same type of AR lens for apple to apple comparison…
Thanks for sharing cannga, all your pictures are great. But, I had hard time following those many “edit” across all yours posts…
Yes that’s the case with the 5 Convoys I have: two S21D’s and one each M21 B, E, and F, all purchased within the last couple months. All 5 behave exactly the same way: purple is seen reflected and green tint is added :+1: . Note an AR lens does not subtract green, it actually adds a small amount of green tint. This article explains why this is so http://rick_oleson.tripod.com/index-166.html .
BTW for me (& pardon me if you already know) the easiest way to check is turn on a table lamp and use the flashlight lens as a mirror to look at the light bulb, meaning looking at the lens from the side and searches for the mirror image of the light bulb. The bulb should look purplish. If it doesn’t, then AFAIK it’s not a properly designed AR lens (see article above). Or at least, it’s not the same as what I have in my latest generation Convoy’s.
You could also use the above test to see if the Optician have added AR properly to your eyeglasses. I found one of my eyeglasses only has AR on one lens :person_facepalming: .
So do you mean those New type of AR Lens from Convoy will add green too? My understanding is they suppose to remove some green “in a/some way”. It’s a “New Type” for that purpose.
Correct me if I’m wrong.
I made a youtube video on how to check AR coating with the light bulb method. You could use this to test your eyeglasses too. 
Look for reflection of lightbulb using the flashlight lens as a mirror. Note how the reflection is purple when you view at a flat angle (flahslight at eye level), then slowly becomes green as you lower the flashlight such that now you are looking down at the flashlight, through the lens. This is what a properly designed single coat anti reflective lens should look like. In between the 2 extremes you could see mixture of purple and green; I believe this is why some people see purple and some see green or mixed purple-green on some lenses.
To view directly on youtube - YouTube. Hope it helps.
Also, the article quoted below explains why it is absolutely normal to see this green tint and why it is likely not visible with naked eyes. The discussion is on camera lenses, but very much applicable to our use.
http://rick_oleson.tripod.com/index-166.html
So, if coated lenses are purple, won’t my photos have a purple tint?
No…. actually, they’ll have a slight yellow-green tint – the extra light that didn’t get reflected passes on through to the film, and there’s a little more of the 550nm yellow-green than there is of the other colors. But* it’s not very much* – glass only reflects about 4% of light from each surface to begin with, and the coating has some effect at all wavelengths – so there’s maybe a couple of percent of extra green light getting to the film. For most normal photography, this isn’t enough to be noticeable in the pictures.
I could only tell you that all 5 of my 2022 Convoy lights behave the same way: purple reflection when viewed from side (flat angle), green tint when viewed from more acute angle, and more or less NO green tint when viewed directly on, without any tilting. My humble opinions - hope it helps:
1. The green tint is “good” in the sense that it is normal for a properly designed single coat AR lens to have a green tint.
2. Whether this green tint is more or less than older Convoy lenses, I don’t know. Could speak only for the lights I have - it’s extremely faint on direct view, to the point of being essentially undetectable during A:B comparison versus a non-AR lens from Emisar. Meaning, to me they are perfectly acceptable AR lenses, and I tend to be quite OCD about hobby things lol.
3. Yes all these Convoy 219b and GT-FC40 pictures that showed spectacular color rendering were through these AR lenses. The green tint is invisible when I did photographic A:B comparison of lens vs no lens; these pictures were posted on page 2 of this thread.
So IMHO no need to worry about AR lens if anyone is interested in buying these new Convoy 27000 lights. Just message Simon on AliX that you want the same lens as the ones he sold to “cannga” buyer in Feb/March 2022. Just kidding.
In that case, buy some New type of AR Lens from Simon. Or when ordering your next light, tell Simon you want New type of AR Lens. Probably by then when you receive New Lens, you will understand my question or what I mean.
I messaged Simon to ask which lenses are on my lights. If there is a new type I will order all 5 and do some comparison. :+1:
I’ve compared GT-FC40 against some excellent and well known LED’s in the 20 or so lights I have: Nichia 519a, Cree XHP35 HI, Samsung LH351D, Luminus SST20 (all of them I like). Here is the most “challenging” comparison for GT-FC40, against the hallowed 219b .
Objectively for me no LED is going to take the crown from 219b any time soon. Its Ra value is a gazillion, its R9 a half gazillion. It’s still the king for accurate rendition and making colors pop.
Subjectively IMHO the GT-FC40 comes closer than any other LED’s in matching the 219b’s fantastic color quality. Maybe even surpassing it. Especially for those like me who feel the magenta tint of 219b is a tad too much to look at for a 45 minute walk for example, the answer is GT-FC40.
In the crop below, I could see this magenta tint on the bark of the tree in the 219b crop. In fact whenever there is a flat light-shade surface, I could see this magenta dominance and it gets to be too much. But this is of course a matter of opinion and personal preference.
Does Convoy GT-FC40 have any advantage over 219b in my Emisar D4V2 and Convoy M21B? Yes, when it comes to actual function related to throw and brightness for a walk light for example, GT-FC40 wins by a wide margin (it’s not even close). Although the throw of Convoy GT-FC40 at ~280 meters is to me still medium class (ie not super like 600-700m), at this point this LED might just be the very best choice for a throwy EDC light with top class CRI and tint. At $30 bucks a pop, the Convoy is a tremendous value and no-brainer must-buy . All IMHO
The GT-FC40 is also a good choice for high CRI sustained brightness in single emitter lights.
A summary from my experience with the 3 lights.
M21B
Beam: Has brightest and most useful spill of the 3 lights, but less throwy. Probably as a result of the smaller thermal mass and less effective cooling, from a Turbo start I’ve found this light steps down sooner than M21F and E. Throw measured to be 280 m by Axios. Hotspot initially slightly dimmer than M21F, but once thermal regulation step-downs have set in, brightness is very similar to M21F. Overall this light is close to the M21F.
Construction & cosmetic:
No onboard USB-C charging. If you want a Convoy GT-FC with rear switch, at this point this and the smaller S11 (thanks @undefined for the correction) are the two choices.
It’s a very good looking light. Smallest of the 3 lights and pocketable. Knurling is not as deep as Emisar for example, but at $30, I am NOT complaining about anything.
I would highly recommend to change rear switch to metal switch from Convoy as it makes the light very pretty and more importantly, makes the click (full press) and tap (half press) much easier, for me anyway.
UI: The well known Convoy 12 Groups. I prefer Anduril but whether 12 Groups is a plus or minus is of course personal preference.
No Anduril means you cannot play with settings such as thermal regulation’s max T (factory setting is 55 C per Simon). Judging by the result (similar step-downs to other lights I have), maybe there is no need.
M21F
Beam: As these GT-FC Convoys get larger, spill becomes dimmer and hotspot becomes brighter. The M21F has a slightly brighter hotspot than M21B. Overall this is a similar light to M21B.
Construction & cosmetic:
Among first Convoy lights with onboard USB-C charging. A very good looking light. Top end is not anodized and not smooth to turn the first few times but now is better.
The side-switch: it “clicks” very nicely, but is hard to press, so not my favorite. My firsts 21F’s switch has a dead zone and needs to be clicked at dead center, which is not always possible. Simon immediately sent a second light without charge and its switch is good.
The side switch is also in same position as the charging port, so I would definitely recommend screw-on or clip-on Convoy clip for example at minus 90 degrees from the switch to locate it quickly.
UI: Still no Anduril, just Convoy UI for Side-Switch lights. Personally I like this UI and prefer it to the 12 Groups.
M21E
Beam: Brightest hotspot, best throw, and dimmest spill of the 3 light, but the spill is still bright and functional. Meaning the beam is balanced and like the other 2 Convoy’s makes for great all around multi-function, multi-use EDC light. Larger light has more thermal mass and better cooling, and this means for example step-downs in this light occur a couple minutes later than M21B and F.
Construction & cosmetic: I am not too thrilled with those diagonal grooves at the head of the light but otherwise it looks good. This size fits more easily in jacket pocket, unless you have loose pants with side pocket (not jeans’ front pocket). I do carry it in side pocket of my pants.
The side switch is same as M21F: Beautiful but short travel and hard to press. This means single click is easy, but multiple clicks are not. OTOH the good thing about this is it protects against accidental activation of the light, which is not a good thing in this high-power light.
UI: Same as M21F, UI for Convoy Side-Switch lights.
IMHO the combination of smallish size and USB-C charging makes the M21F sort of the sweet spot of the 3. OTOH because it is so rare to find a bright throwy light with world class CRI and no green tint, I like the M21E best. Its disadvantage is that it is also biggest and heaviest, and that large top is unwieldy. Lastly, if you like floody light and tail switch, and don’t mind the lack of on-board USB-C charging, then M21B is the one. One of these GT-FC40 4500k plus a Convoy S21D with 219b 4500k would make an incredibly inexpensive and fantastic start/back bone for any light collection with accurate color rendition in mind. You can’t buy anything better even if you want to spend more money IMHO.
You should try out the S11 w/ FC40. It’s an upsized S21B (same exact design, only bigger). Puts out a nice beam with the FC40, long runtime, and feels very good in the hand.
Very interesting Duv measurements in the excellent review by @tactical_grizzly of the big brother, Convoy M21D w/ GT-FC40, Grizzly's Convoy M21D GT-FC40 Review – So Close To Perfect
Note Duv goes down and actually turns negative (becomes more Nichia like with a magenta tint) as output decreases.
