Oh that sounds nice! Simon sure seems to hit a mother load with his 5000k SFT25. Warm and beautiful tint. Unusual and fantastic for a thrower LED.
I sure hope the 5000k version of SFT-42R will be the same. Doesn’t come out in any light yet right? Would be nice if you’ll get one to review. I am tempted to order one as soon as it comes out.
For anyone interested, I would recommend to get Simon’s 5000k SFT-25R now; tint lottery is real.
Lumintop with Osram (830m) obliterates T8 with SFT-25R (565m) in throw distance. But this comes with a price.
The result of both 1 and 2 is that iConvoy’s hotspot is not just larger, but A LOT larger than Lumintop GT Micro’s and GTA’s. Lumintop’s throw is absolutely outrageous , but Convoy illuminates a much larger area. Fun vs function, pick your poison!
It’s interesting that hotspot of T8 with STF-25R is actually quite a bit larger than that of the super thrower Wurkkos TS30S Pro with SBT90.2 as well. Somewhat of a surprise to me because SBT90.2 @ 9mm2 is 4x the size of SFT-25R @ 2.25mm2.
Both Lumintop GT Micro and Wurkkos TS30S illustrate the price you pay for using large reflector to extend throw distance. At any rate, for me the larger hotspot makes Convoy T8, while only an upper-mid thrower, much more useful at closer distance, as a walk light for example (YMMV).
Wurkkos shows the grizzly, Convoy shows her AND her 3 cubs, and signals for you to run for your life 
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I have frequently mentioned “that white ring” around the hotspot. It is an optical illusion called Mach Band effect due to human eyes’ edge enhancement “function,” as explained by the ever “impressive” @ToyKeeper in the post below.
In the bottom picture, incredulous at ToyKeeper’s explanation , I cropped and enlarged a section of that white ring , and the white ring… lo and behold, disappeared into thin air.
Cropped and enlargement of white ring area above:
I was concerned with T8’s thermal management because 1400lm in such a tiny body is no joke, but… no problema. Tmax is highish, 49°C, but equilibrim is quickly reached at ~45°C.
It also looks like all my Convoys (newish models since 2022) will pass the test, the one and only exception remains the S21D. Most have Tmax less than 50°C. On some tests I turned on the fan to test the internal temp sensor’s response. I don’t have automatic recorder so pardon the ugly graph. Temp by IR gun has variations depending on distance to light, ie my eyeballing LOL.
Would it mean that the thermal step-down to some 35% recovered as the light cooled down? It was alleged that it never does.
p.s. I wonder if the T6 driver has a similar thermal response…
p.s.s. I’m fascinated by the plots above. Do you recall what the ambient temperature was more or less and at what time was the cooling fan turned on? ~25°C/10 min?
Good question. There are two parts to that curve:
1. From 0-10 minutes: Shows the light is able to lower output so that T-max and T-equilibrium are not “unusually hot.” Still ok to hold handle, similar to other brands, etc.
2. From 10 minutes on: I’m checking if the internal sensor is sensing lower temp correctly, and sends signal to increase output correctly. So yes to “recovery.”
The defect in S21D is singular: #1. It doesn’t lower output even though Tmax reaches very high. I don’t believe there is a problem with #2, although I did not test for it.
I don’t know about T6. But as mentioned none of my other Convoys has the problem of S21D. And yes T at start around 23-24.
These are the Convoy lights that have “passed”, with appropriate cooling and T-equilibrium in the 40’s (degree C):
M21 B+E+F+H
S21 E+F
T8
Headlamp H2
For the subject of this thread T8 w/ SFT-25R 6500k : Tmax @ 49C and T-equilibrium @ 46C, not surprisingly both higher than the larger Convoy lights. But still essentially “normal” (to hold with bare hand, etc.).
For comparison I tested my fantastic Emisar D4K w/ 519a 5700k DD and Lume X1 boost driver. It runs warm and very steady, tightly controlled, both Tmax and T-equilibrium = 50 C. Interestingly enough, higher than any of the Convoys tested.
Having fun with T8 in my spare time and creating a free ad for Simon :).
Boost driver for AA battery, buck driver for 14500, fantastic beam color for the 5000k version (Duv=0.0002). This light has everything going for it.
I’m really impressed with the capabilities of current lights, I wish they would have been around when I was a bike commuter.
During my “write-up” of the fantastic, near perfect buck-boost Convoy T8 with SFT-25R 5000k, I couldn’t help wondering if I will be buying the same light again when SFT-42R 5000k comes out. Would SFT-42R be better in every aspect, larger hotspot, brightness, throw, and same beautiful tint? Essentially making SFT-25R 5000k obsolete?
As it turns out, it appears the answer is yes to all, EXCEPT for one crucial number: luminance. It appears SFT-25R will out-throw SFT-42R if both in same T8 host with same driver. For me, this means green light for SFT-25R and I will no longer wait for SFT-42R 5000k, but YMMV.
… Unless you drive the SFT42R at 10A - It so happens that a Convoy 17mm 10A buck driver exists.
Excellent point, but 20% more power and heat. In an “all else being equal” comparison, not larger reflector, not more power, etc., it seems SFT-25R is hard to beat as a thrower LED.