Re: Lux levels and run times of some throwers
I guess I'm still a noob so forgive the question if it's obvious . . .
but aren't most, if not all of those lights regulated? How come only the MRV and the Tiablo are the only ones holding full power till death? Is it that the regulation on the others only "bucks" and doesn't "boost" (I hope I have that terminology right!) ?
I'm surprised to see what almost looks like a (GASP!) alkaline graph on some high end performers up there!
The Tiablo A8 has always been on my list but just today I suggested to someone (along with several others) that the DBS would be a better choice for throw. Seeing this first, I would not have said that.
Or am I reading too much into that slippery. downhill lux slope?
:huh:
First, make sure you realize that the plot has a logarithmic scale, and the bottom of the plot is 5000 candelas, before drawing any conclusions based on the shapes or slopes of the curves.
The MRV has a buck regulator, so it does fine with two RCR or CR-123 cells because the voltage of the two cells is always considerably higher than the LED voltage. A single Li-ion cell is a particularly tough case because the cell voltage is just a little higher than the LED voltage for part of the discharge time, and just a little lower for the rest. So it's much more unusual to find a light that gives you flat output with a single Li-ion cell, which requires a buck-boost regulator, than for just about any other kind of battery.
The Tiablo is obviously the only one among these lights that has a buck-boost regulator, which is necessary for good regulation with a single Li-ion cell. But it's hard to get really good efficiency from a buck-boost regulator. You can see that the run time of the Tiablo is quite a bit shorter than the others, so that's the price you pay for the flat output. (All the lights have comparable initial total light outputs.) The DBS and the MRV-18650 plots have just about exactly the same shape as 18650 lights I've put a simple current regulator into, where the regulator actually acts more like a current limiter and provides only very poor regulation over most of the discharge time.
The DBS is really just a receptacle for a number of pills, each with its own very different characteristics. So you shouldn't consider this to be representative of all, or even most, DBS flashlights. It shows only the performance of the 1S pill, which is one of the earlier ones. I've seen plots of some of the others on CPF, and you should take a look at those to get a better idea of the capability of the DBS and what pill you might want to order if you ever get a DBS. I'm sure some are flatter and/or brighter.
I personally prefer the MRV over the Tiablo for a couple of reasons. One is that I use a thrower when I want throw, so I find the mandatory switching through the low level to get to high with the Tiablo to be a nuisance. I could of course short circuit the low level resistor, but then I'd always have to click a second time to get the light to turn off. The other reason I like the MRV better is that its hot spot is noticeably larger than the Tiablo, which is too small for my taste. The energy difference seems to be going into a slightly brighter spill in the Tiablo, which I don't find particularly advantageous for a thrower. (I virtually never carry a thrower by itself, but with a more general purpose light.) The MRV has an additional level -- which I never use -- but you don't have to switch through it to turn the light on at max or to turn it off.
I love the D-Mini for is combination of extreme brightness and small size. It's my see-far light when I go backpacking or otherwise want to keep my load small and light. It's really in a class by itself.
I just got the DBS (used) so haven't had a chance yet to get to know it. I do like the 1S pill's single level, and it has a good combination of throw and long run time with an 18650. It's likely I'll be getting one or two additional pills to try out.
c_c
