Not answering your question directly but a thing to take into account:
Do you need wide or bright side illumination? Or both?
I ask because reflector depth has a big impact on the side illumination (which we call spill).
A deep one will produce narrow spill that won’t hit many things around you. Therefore it will disturb your vision less.
A shallow will produce wide spill that is very useful f.e. while walking.
Note that spill brightness is not affected by reflector but purely by LED output. The brighter the better.
I was thinking the XHP35 would be best, but its a 12V (isn’t it?) so I was worried being a different voltage it might require less efficient drivers and thus would produce more heat? Perhaps my logic is off, but that’s why I figured I’d defer to y’alls superior knowledge
As for the width to brightness of the spill, ideally I’d want both, but I think it would be best to shoot for wide for peripheral vision and situational awareness; I don’t need to see the critter in detail, just know he’s there and off to the side. Does that make sense? lol
An xhp35 is a 12v led, so off a 1 cell light it needs a boost driver to work (step up 4.2v to 12v). Simon sells a really good boost driver on Aliexpress Xhp35 Driver US $9.65 | XHP35 HI driver, run on single lithium battery 3.0-4.2V, output current max 2.3A, 4 modes 淘宝网 - 淘！我喜欢 but it’s 22mm diameter so take that into account as it may or may not fit the KR1. I think you’d be good with an sst40 or maybe ab xhp50.2 3v led. The 50.2 gives good spill and decent throw. The sst40 throws more and also gives good spill. They both run off a single lithium ion.
I’m not sure, I don’t have K1 but looking at the picture I think it has a somewhat narrow spill. It may not be the best host after all…
This reminds me of an old thread but I’m not sure if it’s still relevant.
Increasing voltage is always at least fairly efficient and sometimes very efficient. Decreasing can vary from very efficient to inefficient.
In the case of K1 the XHP35 driver will be more efficient.
But driver efficiency is not as important as LED efficiency.
I’m not sure but I believe that at the same spill brightness (or lumens - these are directly proportional to spill brightness) SBT90.2 will be more efficient, consuming less electricity.
At the same spot brightness, XHP35 HI will consume less electricity. But I’m not sure if it will be more or less efficient (because efficiency is basically light-output divided by power consumption. SBT90.2 will consume more power but it will also output more light).
If someone wants both flood and throw, one easy option is to put some DC-Fix over the lens of a thrower. Perhaps even just part of the lens. That will reduce throw and convert it to a very wide flood area… and you can adjust the balance between the two by changing how much of the lens is covered. One good compromise is to put a circle of the stuff right in the middle of the lens, because that will provide good short-range flood without affecting the throw distance very much. The throw part of the beam mostly shines through the outer edges.
It is pretty simple, leaving aside the voltage and current all that jazz as you say, the SBT90.2 will draw from the cell on Turbo 100-120% more current. So the heat generated by the SBT90.2 is much more and the stepping down much faster.
Also if you want to use medium modes, not full turbo, the XHP35 HI driver will have a more efficient driver, not because it draws less power, but because it converts it more efficiently. I still think 1 flashlight 1 cell approach is not a good one, having a spare cell charged up is the simplest way of stop worrying so much.
Without going into lots of technical questions which can often be wrong I think it is clear that it is the XHP35 HI that you would want.
This is a cool idea! I would excruciate over centering the the circle, I guess you could do some marks with a whiteboard marker to help get the middle.
If my mind ray-traces it correctly, a small piece of DC-fix at the centre of the lens will create a 3-stage beam:
spot, formed by light bounced off reflector
spill, formed by light missing the reflector
flood, nearly 180 degree, formed by light diffused by DC-fix
It should indeed have near-zero effect on throw. The flood will be very dim relatively to spill (let alone spot) because a small patch of DC fix won’t capture a lot of light and this light will be spread over a large angle. And note that DC-fix is not perfectly diffusive which means that some light hitting it won’t be scattered. It is usually desirable but some stronger diffuser might be better in this application.
There might be a dimmer area of spill just around the spot - the light captured by DC-fix is taken from this area.
A larger diffuser patch will make the flood brighter at the expense of capturing some of the spot light - which reduces throw.
Still, I wouldn’t expect it to be get very bright without seriously compromising throw simply because the diffuser needs to capture a lot of light to make 180 degree bright.
Is the beam going to be much better? I guess it depends on one’s needs and preferences. Personally I don’t like 180 degree lights because they blind others a lot and make it easy to accidentally blind yourself. But there are also people around who love them.
Well, I’ve gone ahead and ordered the XHP35 HI 4k (I find warmer light outdoors more useful), and the DC Fix… is an awesome idea actually… now I’m sure I’ll devote an unreasonable amount of time experimenting with that haha! Thank you, TK, I’m pretty excited to fool around with that, and heck, if it’s a 3 stage beam, I’ve not seen that before and am anxious to witness that in person lol
Now the question involves the battery… Samsung 50E for the mAhs or Molicel P42A for the draw… How much does a single XHP pull? Since the voltage is being stepped up to 12V, does it require the battery to push more current in order to feed the proportionally reduced current after the voltage step-up? I’m overthinking again, aren’t I…
Once again, y’all have been extremely helpful and I can’t thank y’all enough!
Get the Molicel P42A, lower internal resistance cell will result more time on Turbo, no need to overthink too much.
And get 2 cells not a single 1, more fun that way, rather than go and have to recharge because you used Turbo too much.
My EDC is the 8-led mule KR4 lol… its basically 170* of pure, even light… though it gets fairly toasty at moderate-high levels… and turbo is usable for literally SECONDS at a time… but man, even at moderate levels, it’s ability to provide a fairly substantial wall of light makes it by far my favorite for indoor use and for walking the dog … as long as no one is 170* in front of me O.o
Actually, I really should contribute more lol; I’ve not seen a single review of the mule KR4 so I’m assuming either a) it’s too niche, or b) people are on the fence about it, so I do have the opportunity to help with that regard, but I guess a beam shot of a mule setup would be kind of pointless… and also I’ve no ability to take beam shots of any value… meh, at the very least I’ll try to put together a review as best I can and see if I can’t find a way to take pictures that’ll be worth it _
I feel that this could be a dangerous rabbit hole to explore… as an example, I was somewhat interested in reloading ammunition once, so I figured I’d give it a try… next thing you know, I have a portable doppler radar, a true (and far more precise than necessary) analytical balance with a set of ATSM class 2 calibration weights…calibrated each session LOL, concentricity gauges, micrometers (yes, more than one o.O), comparators with a series of gauges differing by only 0.001 inch diameter each for specific bearing length/ogive measurements, more goofy tools that are more specific than practical, and spreadsheets dictating the life of each piece of brass, including weights after trimming, exact powder charge measured and added, velocity of that firing, etc.
Basically, I have a tendency to keep going down the rabbit hole until I’m well inside of wonderland
I just received my K1 in dark brown... but it doesn't really look brown, it's just a warm-ish dark gray. Very subtle, not at all like the photos on the website (I have a calibrated monitor). The box says "gray", too... is that normal? It's definitely not black, that's for sure. Could someone chime in who also received a dark brown one and confirm it's marked as "gray" on the box instead of "other"?
Also, is it normal for a large reflector like this to have lots of small pits in it? Like, they're really small, but they look like someone took a dull needle and poked the reflector randomly 10 to 20 times. Very hard to take photos of, as you ideally need some kind of moving pattern reflected in the reflector to clearly see the pits and how they bend the reflection around them. Largest reflectors I otherwise own would be the Nightwatch NI40 and the GTmini, and those don't have a single pit in it. I realize this is probably mostly a cosmetic issue, but is this something I should worry about? It certainly makes me less happy about the light overall, and we all know most of us don't buy lights just as tools but to appreciate their beauty and design.
It’s a dark grayish-brown in my opinion. I have three K1s (one in each color) and it looks brownish when I compare it side by side with my black one. The brown color is more evident if you view it under natural sunlight. Unfortunately, I don’t have the box anymore to see what it was marked as.
I don’t think that’s normal. I just checked my K1s and two of them have flawless reflectors while the other one has one tiny pit that looks like a needle poked it, which I never even noticed before until reading your post. 10-20 sounds like an awful lot though. I think that would bug me even though I doubt it has any significant effect on the beam. Maybe contact Hank and see if he can offer a replacement.
