Thanks for this great information!
Have you considered adding the M21D to your testing?
It comes with the same GT-FC40, usb-C charging, etc… just with a larger head/reflector.
I would love to see how the beam profile of the M21D compares to your already impressive stable of thoroughbreds.
@Caleb thanks for the nice comment. M21D curiously looks nearly identical to my Wurkkos TS30S, but oddly quite a bit heavier (286 gm vs 230 gm). I was looking for the perfect everyday all around walk light so this is a great light with better throw but would be too heavier too big for my use.
This next picture might be one of my all time favorite flashlight pics :-). For anyone new to flashlights, I’ve mentioned the ability to reproduce RED (R9) as being extremely important for color fidelity, I hope this picture shows why some of us talk incessantly 
about CRI and R9. And how LED colors could vary so wildly.
In real life the color of the bougainvillea is bright red. See how SST40 turns it violet, GT-FC40 5300k improves the red, and GT-FC40 4500k reproduces it beautifully.
Yes but the tree above the flowers has quite a lot of yellow tint on it. Was ie exaggerated by the camera?
@phantom, great question. It’s partially the light green-yellowish younger branches that the other 2 LEDS turn green, partially visual effect of a crop comparison of a lower CCT vs higher CCT LED. If you look at the big (non crop) picture of FC40 4500 by itself, the yellow color is not as prominent.
Followed is another pic the GT-FC40 without cropping vs similar CCT LED’s. The 2 shots with question marks 
: one is GT-FC40 4500k, the other is Nichia 219b 4500k.
Now I could tell the 2 LED’s apart because of certain clues, but when I first had the FC40, it was not easy. That’s why I call GT-FC40 4500k the Nichia imitator. In some aspect I actually prefer FC40 color rendering to that of the magenta Nichia.
And both Nichia and Getian make the other 2 LED’s look so green or yellow. All pics taken with Canon DSLR in RAW format with WB fixed at 5000k.
Cannga,
To compare the M21D to the TS30S seems odd to me. They have vastly different use cases.
(I read your post/review about the TS30S and was quite impressed with the amazing throw. I’m not sure that I would ever need to see anything that far away. I would probably need binoculars. Haha.)
I don’t think these two lights as comparable… except perhaps a similarity in overall dimensions.
As you have pointed out many times, the strong suit of a GT-FC40 light is it’s excellent color rendering… not super throw.
I do see how the M21D’s weight could be a deterrent to adding it to your collection though.
Cheers!
Sorry Caleb if my post was confusing. Yes I was referring strictly to the physical dimension: S21D is same size as the TS30S, and for me that means it’s too big & too heavy to use as my walk light. And sure GT-FC40 and SBT90.2 are two completely different-purpose LED’s. I put up with TS30S size and weight only because the SBT90.2 is a heat monster and I don’t want any host smaller than that Wurkkos.
The TS30S — cannot recommend it high enough. It’s eye opening (pun intended) and ridiculously inexpensive for what it does. I know you were kidding but allow me to add a small point: Throw of 1000m as you mentioned doesn’t mean now I could see at 1000m. Most importantly it means that at every distance closer than 1000m it’s x times brighter than say a light with 500 m throw. I use my TS30S mainly to play around, nothing useful lol, and look at things typically 100 m away, and even less, wherein the TS30S shines like a lighthouse.
For my older eyes I’ve found the true usefulness of a throw number is uh maybe around 1/3 to 1/2 of its value. For example, for my eyes 150m throw (those quad Nichia w/ TIR optics, S21D and D4V2 HERE) means that light is truly useful up to around 50m.
I totally agree with Caleb.
Seriously, @Cannga… Pardon me. I do find your posts confusing and misleading all along.
You have been editing and editing and editing and editing all your posts from Day 1 you join BLF. Pardon me again. Why don’t you get your facts and data right before posting?
Anyway, to each his own, But to me, I will only post something that is 1+1=2 that no one can dispute about….
I’m sad about this thread : BLF dying?
that where are all the experts? Why is it NO ONE correcting Cannga for his misleading post.
Lastly, I do appreciate Cannga sharing, sharing that is facts and true. But once again, too many confusing and misleading posts that I totally object.
I’m surprised at the strong emotion, over something so trivial. Very much agreed that sometimes my writing is not clear and will try to slow down and not write at the same skipping steps as my brain. But misleading? Subjective opinions always noted with “IMHO” that people disagree with yes, but misleading never. Please give specific examples that I am “misleading” - over $30 flashlights? Are you serious?
Thank you for appreciating the objective data I shared, but flashlight opinions (!) shouldn’t cause you to be angry/upset. I edit posts all the time to make them clearer, even now sorry, and if even that upsets you then maybe it’s time to stop reading this thread.
First post: @Caleb thanks for the nice comment. M21D curiously looks nearly identical to my Wurkkos TS30S, but oddly quite a bit heavier (286 gm vs 230 gm). I was looking for the perfect everyday all around walk light so this is a great light with better throw but would be too heavier too big for my use.
Second post: Yes I was referring strictly to the physical dimension: S21D is same size as the TS30S, and for me that means it’s too big & too heavy to use as my walk light. And sure GT-FC40 and SBT90.2 are two completely different-purpose LED’s. I put up with TS30S size and weight only because the SBT90.2 is a heat monster and I don’t want any host smaller than that Wurkkos.
Re. GT-FC40 5500k
I just edited post to add numbers from Simon of the 5500k version of this LED.
I thought that the 4500k version has better CRI, but it turns out they both have very similar Ra and R9 numbers, both are excellent R9070 LED. If anything the 5500k has lower Duv (partially explaining the magenta corona I am seeing in beamshots?).
The B35AM light left China so should be here shortly. :+1: Can’t wait to see how it compares, if it is indeed “four Nichia E21a”.
Beamshots of the 3 lights. I love all 3 lights and LEDs despite that they look differently from each other. ie They are good for different reasons, and preference is subjective so no right or wrong. Like have different wines that you enjoy. 
All IMvHO - all pics with camera WB fixed at 5000k:
SST40 6000k has a slight bluish spill with some green in corona. High CCT LED gives a certain subjective crispness to the scene, and that’s why I like it.
GT-FC40 5500k the new light that I just bought: a surprising magenta tint. Despite of the magenta tint in the beamshot, in real life use to my eyes it doesn’t look magenta like 219b 4500k, more like a “neutral tint day-light look.” I also like this light a lot simply because it is different from the warm 4500k color: 5500k verision is (obviously) “cooler” looking, with more subjective crispness. I like variety and wouldn’t want to be without it. Simon’s measurements show this to be a R9070 LED, which is outstanding.
GT-FC40 4500k beam color to my eyes is best described as dark peach (? - but really doesn’t matter) with a hint of magenta in the corona. This is my personal favorite because I prefer a warmer CCT. In actual use it looks like 219b 4500k (will post pic later).
I will repost the scenic pictures so you could correlate beam shot to scenic shots.
What sort of camera settings do you use? What white balance setting for example. Thanks.
You may be surprised how throwy it is as it’s much smaller than GT-FC40.
Thanks for the heads up. Good to know in case I mess up the measurement.
The light is here in US, “at customs.” Should be a lot of fun in a few days.
Hello Chicken Drumstick (there must be a story? :+1: ), followed is what I use, hope it helps. Camera always on tripod, flashlight usually resting on second tripod for the outdoor shot.
WB is most important: I always fix this at 5000k. To best of my knowledge this is similar to what most reviewers use, the range 5000 to 5500k. I personally use 5000k because IMHO this looks closest to the actual view I’m seeing with my eyes. The fixed WB also helps because it means pics I took 6 mos ago could be compared to the ones I take now for color eval.
Outdoor scenic pics: I’d test a few settings then settle when I got the exposure that looks most like real life (ie subjective). Nearly always start flashlight at 100% brightness. In this case:
For M21E, F, and Nitecore: ISO 160, speed 0.8 sec, f/3.5 (same setting for the 3 lights so I could judge their brightness)
For S21D: ISO 160, speed 1.3 sec, f/3.5 (dimmer “hotspot” so slower speed to get good exposure).
Focal length 24 mm of a 24-70 Canon zoom.
Indoor white wall beamshot: Always in complete darkness.
Exposure depends on whether I like to expo for the corona and spill or for the hotspot. Often I like to see corona and spill so hotspot sometimes is over-exposed in the middle. So WB also 5000k, then I would take oh up to around 10 shots in a row at increasing speed w/ same aperture, and choose from those the one that I like (ie subjective). In this case:
ISO 160, speed 1/1000, f/6.3, 38 mm focal length.
Wait… what happened?
What did I miss?
It’s a little OT but here is comparison of Getian FC40 4500k in Convoy M21E with two great LEDs with great CRI numbers , Nichia 519a 4500k and 219b 4500k in Convoy S21D. Note unlike previous comparison, the red bougainvillea is reproduced accurately in all 3 LEDs.
In comparison of lights with different throws and hence central brightness, I adjust exposure to make the central area looks as close to each other as possible (completely subjective). In this case the Nichia 519a has lowest throw so get expo increased more than 219b, which gets expo increased more than FC4500k.
FC40 4500 resembles 219b, but not quite the same. Peach color (FC40 4500k) versus magenta (219b 4500k) in the beamshot. This is just for fun: peach is mixture of magenta and yellow, why the FC40 4500k looks more yellow?
219b is the best for color accuracy.
imho.
I would like to add that for whatever reason my Nichia 519a 4500k measures much lower CCT than spec. The latest round of measurement showed CCT of just around 3900k with the Opple (which correlates with specs very well when used to measure other LED’s).
Meaning if true the above comparison is not exactly of 519a at 4500k. It’s a 3900k LED which would look warmer.
Not sure at all but I vaguely recall reading somewhere that some other owners have seen this much-lower-than-spec CCT with 519a?? Anyone please correct me as needed.
I haven’t Opple, but my 519A 4500k measures a little bit over 4500k.
My 4500k and 5700k are much lower than spec. 2700k was pretty close. This was using hotspot measurements.