Yeah it’s there in both L7 and L8. BTW he has another video of a light with SFT40 and the pattern of white ring around a colored center is there also. The TS Pro has the most “saturated” color in center and that’s why the ring stands out so much.
My RAW picture software allows me to look at intensity and I could confirm that the ring has the same brightness/intensity as the center. It’s the difference in color (vs white) that makes the ring stand out.
I have one of these on the way for testing/review. Should be interesting to see how it does. Like others have said, a ringy beam isn’t ideal, but on a thrower it’s not a deal breaker. Donut holes aren’t unheard of either on throwers at really close ranges with LEDs that have bigger LES. The Thrunite Catapult Pro has one up to about 1 meter.
I’m afraid it might not be that simple. It’s not a dark donut hole at close range. The “hole” is actually intensely bright, just greenish. Also, it’s visible up to 30 yards away.
And yes it’s ringy at periphery, but that’s not what we are talking about either. Bright ring at periphery is annoying with close distance white walling, but disappears by 20-30 yards when the beam enlarges.
The problem is in the hotspot, right in the middle of view. The first pic below shows some throwers, all with the same pattern: a white rim around an intensely bright but colored center. In these lights it’s not that visible at distance. In the TS30S Pro it remains prominent up to about 30 yards away.
I waquely remember reading from Wildtrail WT90 thread, that slightly darker appearance on the center of the hotspot is because of the perfect focus. It was Texas_Ace’s explanation of the issue, but I can’t remember it word for word.
Probably due to the slightly larger reflector. Even a small differemce makes a difference. I did see it in the WT90 as was mentioned, but its not terrible or a deal breaker. Again, remember this is a sub $100 Sbt90.2 thrower so it won’t be perfect. The Sbt90.2 is known for having positive duv and a little green tint even at moderate power levels (some better or worse than others). The first gen of this light is better in some ways, but this one does what a thrower does and that’s throw at the cost of some irregularities in the beam.
The white outer ring with dimmer-looking center is usually caused by Mach banding. It’s not a flaw in the beam; it’s a quirk of the way humans see.
When brightness changes in a linear pattern, it makes a sharp “corner” at the beginning and end of the line. This corner then appears brighter or dimmer than everything around it, even though it’s not.
Here’s a diagram showing the actual vs perceptual brightness of Mach bands:
… and when the pattern shows up in a flashlight beam, it usually looks like this:
The hotspot should appear as if it has a white ring around the edge, with a darker inside. The center may even appear concave like a bowl. But it’s not. It’s perfectly flat.
If you have an image viewer with an eyedrop tool, feel free to check the image. The entire hotspot, including the “brighter” edge, is a single color – #e6e6e6. The white ring and concave center exist only in your brain.
That doesn’t mean the beam is perfect though, even if it could technically be described that way due to a completely flat hotspot. Focusing like this is a great engineering feat, but doesn’t look very good. Instead, an ideal beam should be tuned to match human perception.
To avoid the Mach band effect, the changes in brightness should generally follow sine curves instead of lines. This is one of those weird cases where a straight line looks curved, and a curved line looks straight.
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As for the color of different parts of the beam, that’s a completely different effect with a different mechanism. Mach banding doesn’t affect the color; only the brightness.
I can’t remember who it said, the Mach Band stuff is to enhance contrast and detect lines by nature of the human eye. It makes it easier to see a tiger in high grass.
(if you are too slow, you are food!)
Wow thanks @ToyKeeper for taking time to write the detailed explanation. How interesting!
My measurements with Opple AND photography software show same outputs between that white rim and the center. That seems consistent with your explanation.
At 6 meter away, the beam is large enough that I could also measure CCT and Duv to document the change in “color” between center and rim. I will do that test next.
Thanks for that info. I wonder how they would design a reflector to do that?
Interestingly, I had my TS32 out last night. Using the Spot (SFT40, I think), I noticed the same effect. Not as pronounced as the TS30S Pro, but it is there for sure. I just have to stop looking for it… easier said than done I am afraid.
Thank you ToyKeeper–now THAT’s a satisfying explanation!
So far it looks like this phenomenon is present in only some domeless emitters (SBT90.2, SFT40) but not others (XPL HI, Osrams, dedomed 519A, etc). The SBT and SFT also happen to be the only emitters to have a rough phosphor surface instead of a shiny one like Osram or a thin layer of transparent material like 519A. Wonder if there might be a connection…
Sorry all the brouhaha’s with Wurkkos TS30S Pro interrupted my mini-review of Mateminco PD90S 
. Two things stood out about this light:
I am not sure but this has got to be the most “powerful” LED (highest output) on the market right now? For that, I got it for $57 during Nealsgadgets’s Christmas sale. Now it seems to be available for even lower with coupon on MATEMINCO’s Aliexpress shop CLICK HERE. What an amazing deal for this powerful and beautiful light.
Measured output is not close to 9100 lm spec, but still fairly shocking at 7400 lm. Considering the 62 A max current spec, I would recommend only two batteries for this light:
The new most monstrous kid on the block seems to be the SFP55, which uses a 5x5 layout instead of the 4x4 of the SFH55. Neal is claiming 17K lumens with his Lishen battery.
It is in the Super Valkyrie at nealsgadgets: NIGHTWATCH NI03S Valkyrie SFP55.2L 17000lm 748m 21700 Thrower LED Flashlight – Nealsgadgets. I picked one up over the Easter sale. Seems like it should be here soon enough.
Also the Lumintop Rattlesnake. The 1Lumen review of the Rattlesnake shows the output dropping from claimed 16K lumens to 1K in a mere 15 seconds. It must be a glorious 15 seconds, though…
So hard to decide which I want to go with, because they’re about the same price.
I have to wonder what the PD90S performs like with a smooth reflector, it could probably be custom optioned. Also is the PD90S easy to update to Anduril 2? On a hotrod like it, having temp-unregulated momentary turbo is a requirement.
Isn’t 62 amps pushing it for any of the currently available cells? IIRC, the P45B is only (?) rated for 45A continuous. How fast does the PD90S step down? How hot does it get before stepping down? How hot at max sustainable output?
BTW, does it come with a 26650 to 21700 adapter?
I have the Super Valkyrie SPF55.2 in for testing. Sneak peak…
With Lishen 2170HP 55 amps on Turbo at start, 48 amps at 30 seconds
30T also 55 amps, but down to 43 amps at 30 seconds
No Lumen outputs verified yet, but looks to be about 13K-14K at start?
More info to come in the review!
Also have the NS14…
For the 26800, I have a special 26800 from the original Valkyrie that did 40 amps at start. The Queen Battery QB26800 did 38 amps. Pretty decent for 6000+ mAh cells!
Oohh I like this! Too bad I have so many lights I don’t need already. Lumintop Rattlesnake is hold to turn off, which I personally hate, and so expensive. But this nightwatch is only $70 something. Size is so small so output I’m afraid will die quickly but still… hmmm hmmm hmm 
62 amps is spec for LED, battery will supply whatever it could, and I think Neal’s Lishen comes closest.
There is a review with run-time on this light I’ll post. Steps down and bottoms out in 1 min, then recovers very quickly, rest of time around 1200 lm in my light with Tmax=60 C. 1200 lm sustained is about as high as I’ve seen in all my budget lights. Meaning it’s excellent.
AFAIK, this, and most Chinese LED lights, because of the large size of the LED will be flooder, NOT thrower like SBT90.2. That beautifully-throwy beam of Wurkkos TS30S won’t be seen here. OTOH PD90S is better for near field, and illuminates larger area.
Seems like the ND25F coupon still works on it, so only $60. 
You’re making this difficult . Could you confirm that UI is NOT hold-to-turn-off?
UI is hold for on and off. However i got used to it real quick since that light is bonkers. May be the brightest single led flashlight available.