It’s just anodizing like on pretty much every aluminum light. However, there are different ways of doing anodizing, and the anodizing finish chosen on these lights results in a grainy unpolished finish, rather than the much more common smooth finish.
I have a few lights with a grainy finish like this:
White Emisar D4 (quite grainy)
Blue Emisar D4 (grainy, but not so much as the white)
Sunwayman T26C with tan finish (quite grainy)
Yellow Fireflies E07 (quite grainy).
Olight S10 Ti bead blasted. It’s not grainy anodizing like the others but has that same grainy chalky feel as the other lights.
Overall, I’m not a fan of the grainy finishes. Feels like I’m holding a stick of chalk. The texture just doesn’t feel good in the hands even though it does noticeably increase grip. I’d much rather have smooth anodizing with knurling for increased grip.
I didn’t realize that other brands were using that finish. It does make sense that it would be annodized, especially seeing that the inside of the battery tube is smooth anodize. I’m kind of with you, it looks nice but it’s not nice to feel with dry hands. If my hands are greasy/oily like with lotion or actual grease/oil it feels a lot better, but dry hands it feels chalky. If it is anno over media blast then it seems both together make it chalky.
This would be cool, but isn’t the FET more efficient on turbo then any buck/boost driver because in those all that current would have to pass through the inductor unless there was a bypass. I don’t know why the FET isn’t run in the transistion zone as a voltage controlled resistor which is essentially what the 7135 chip is. Obviously the FET would be using power so it needs to be cooled, and you probably would need a current sense resistor to keep the light regulated. This isn’t the most efficient but it could be more efficient in the 300-2000 lumen range then current PWM. I don’t find myself burning through 18650s like I was burning through single rcr123a and AA lights so maximum efficiency isn’t that important to me as the overall size of the light.
I would think that FET is most efficient if compared to a different driver pushing current at an equivalent value. Problem with FET is that the LED is running at a very inneficient point on it’s watt to lumen ratio. The other problem with FET is that it’s not regulated so output will steadily drop as battery voltage diminishes.
For those interested in sustained regulated outputs at various levels, buck or boost drivers are able to deliver the constant current and also drive the LED at a much more efficient level. It will also benefit from the low VF LED unlike a linear driver.
If peak output at turn on is your thing, FET makes total sense.
If you want to run the light at a constant 1000 lumen level (heat dissipation and PID aside) buck and boost drivers are fantastic. I love being able to turn on my dqg tiny 7 x 219c at medium or high and know I can rely on a consistent output over a very long duration of time without worrying if my battery is full enough.
I think FET lights are successful in the emisar lights because of the peak lumens and genius pwm programming of the driver.
I think if Hank releases another line not focused on winning the lumen war but on efficiency more similar to Zebralight, he will have another wave of success… Fingers crossed.
A FET can be run as a regulator instead of PWM, that’s basically what is inside a 7135. You could drive the LED at a constant current and therefore the LED would be high eff but theoretical downside is you are burning voltage with the FET. Basically a FET run this way would be the same as infinityx7135 lights.
The aim of the D4 (and Meteor) was to cram as much power in a comparably tiny package. Buck or Boost with drivers (with similar power) which require an inductor would inevitably increase the total size of the light or require significantly more complex machining (like creating a recess in the Emitter shelf to accommodate the taller components of the driver.
The FET solution is slim, cheap and gets the job done. Yes, there are drawbacks, but each other technology would have drawbacks as well, just different ones.
I completely agree with you. There will be compromise on both ends.
So now that the more affordable, compact, peak lumen D4 and D4S are available, it would be a great complement if Hank released a slightly longer, more expensive, regulated efficient version with the same emitter options. The driver on a buck boost is indeed larger and more complex, but Hank was able to make the smallest pop can light in the M43 that is still relevant today, so I have no doubt that he can reproduce his magic on a single cell version.
I think thats one of the things that makes Emisar’s so successful, its the fact that you have so many great emitter choices. As far as I am aware, there are no options like that for an efficient regulated light via buck/boost with the exception of the Noctigon Meteor M43 and quite possibly the Zebralights (not quite as customizable as the Emisar in emitter options).
If people are owning multiple Emisars of the same model in different colors and emitter options, I think these same people will also buy a regulated buck/boost version.
The opportunity for Hank is there and I think the demand is as well
While HWang is taking djozz’s suggestion regarding regulated D4 permutations into consideration, Nichia E21a/Optisolis versions, perhaps even mules could be offered.
A current regulated aspheric D4 with 4+ emitters of the category, and 18350 tube would be tempting.
I’m hoping that a single emitter D4 (D1/4th?) will be created. I love my D4 with Nichias but it doesn’t get as much pocket time as I thought it would because of the extreme power and the possibility of accidentally turning on. I keep it in a Convoy holster but that keeps it from being an EDC light.
Less power, but still small and having a great UI would be a welcome addition. Maybe with an XHP35 HD or HI?
I also hope that they try to revive their 7 emitter design, but not with a trio of 18650s like they had planned, but with the capability of using a high drain 21700 like the 30T.
Linear FET drivers like that exist. For example, led4power makes some. They’re typically more efficient than a PWM FET driver, and slightly more efficient than a FET+N+1 driver… but less efficient than a boost or buck at most levels. Because instead of burning off extra voltage as heat, a buck driver converts the extra voltage into usable power.
