Still going through my backlog. Next up:
The Acebeam L19 v2.0 a very long-throwing hunting flashlight, featuring a TIR lens for maximum throw with minimal spill. Powered by a single included 21700 battery, the light features dual electronic and tactical switches. Very distinctive build, as you will see in the review. And the performance?
An outstanding thrower, especially with the Osram emitters.
Check out my full review for more details!
Excellent review as usual. Love Acebeam.
Why do the L19 have a slow taper downward on the runtimes versus the P17? I thought the draw to the Acebeam was their flat output drivers but this doesn’t seem to be the case. High and Medium sea to have a flatter output and a quicker drop off so is it heat related?
Those 50.3 and 70.3 lights use boost drivers, which can offer a better stabilized output. Coupled with the fact that 70.3 is a lot more efficient than SFT40 (or PM1), they have a longer, flat output than the SFT40 thrower.
Buck driver can provide stable output, as long as Vbatt is higher than Vf + driver voltage drop (which is usually substantial, like 0.2 - 0.3v). Below that there is no regulation. The higher Vf an emitter has, the worse it will perform with a buck driver. At 8A output, PM1 needs Vf of 3.6v and SFT-40 needs Vf of 3.45v. As a result the SFT-40 version of this light should have longer stabilized output.
Hmm…
That’s something that I suspected.
What would be nice is a bright & throwy emitter that is about as efficient as an XHP70.3 HI.
I guess CREE would have to make it. 
To be efficient, you need a lot of silicon running at lower current. 70.3 is a big ass emitter with 4 dies and there is no way around physics.
BTW you can actually make 70.3 as throwy as SFT-40. All you need is a reflector with diameter of 120mm or bigger. LOL.
Well said! 
