ToyKeeper
On the throw side of the equation, do you think we can get much past the mile mark?
Yes, but low quality do not mean useless. Absence of peripheral vision called tunnel vision it is disease.
I hope you are not writing this as if tunnel vision is a negative property?
In some governmental professions this property is mandatory 
Eye-tracking flashlight would be great for someone with tunnel vision
Yes it is negative property. You can ask some one with this disease.)
Great topic. All technological developments reach plateaus. There are limits in physics where LED’s are concerned, somewhat analogous to the sorts of limits that CPU efficiency & performance has faced—heat. And while you can have active heat reduction systems, they cause notable battery drain. Heat build-up is what keeps an LED from being able to throw for long periods. Take for instance the FW21. 10,000 lumens! But, it lasts mere seconds.
Now there’s LEP… which produces less heat. It’s of course a very focused beam, but aside from producing a hybrid flashlight (adds LED’s for spill), maybe there’s some innovation with optics to be had. Something better than your typical “zoomie” approach.
when thinking about flash light, I think in addition to improve led efficiney, it is also important to consider:
- Driver electrical efficiency - I will like to see more driver with highly efficient driver, not using amc7135 linear mode
- Flashlight resistance - build quality and contanct points
- Battery technology - toykeeper point out that it will be good to have long lasting flashlight at same brightness, so combination of high effieincy driver with high capacity battery can lead to very long run time
Great topic. Something I think about whenever I research flashlights and led tech in general. If you ever need an example of how far leds have come in the last 15 years, look outside…vehicles are switching from halogen and even HID headlamps to led. Many cities (they just did a major retrofit of our streetlights to leds city-wide) are upgrading the street and roadway lighting to led. It’s longer lasting, requires less maintenance, uses a fraction of the power per lumen vs high pressure sodium arc lamps (instant-on as well). Traffic lights are switching to leds. Building lighting for commercial and residential is going to…you guessed it, leds. My office complex is all led interior lighting now thanks to COB, CSP and SMD led technology. We get to enjoy this tech as well in smaller, but high output and efficiency leds. Even 7 years ago something like the xhp70.2 or 50.2 in 3v wasn’t possible, but now it’s fairly standard.
Where’s the road end though? I think we’re at a plateau for now until other technology catches up.
There’s also this thing called peripheral vision…
…
that’s like using a laser as a flashlight.
The VR thing works because it still renders everything in the peripheral vision.
A better option would be a beam pattern like a generic thrower that still has a good spill that is eye tracking…
It still won’t be the same as a big flooder though
Yes, but again, it’s a matter of diminishing returns. More throw means bigger lights and/or more laser-like beams. In one case, the limit is how big the light can be without getting ridiculous. In the other case, the limit is how intense the beam can be before the glowing air obscures whatever it’s aiming it at. And both are limited by how narrow the hotspot can be before it’s no longer useful.
The amount of power required scales along a pretty unfortunate curve, too. Shining twice as far means spending four times as much energy. Shining 3 times as far means spending 9 times as much energy. So it can be done, but it gets so expensive it’s eventually not worthwhile.
LED efficiency is great at relatively low currents, but as others have mentioned efficiency at higher current densities can still be improved. Of course, the current density is one of the important factors in getting high luminance. This is great not only for flashlights but for general lighting as well: the ability to drive LEDs harder means you need fewer of them which means less cost. There is still fundamental research going on to better understand the causes of efficiency robbing “current droop”.
I’ve been feeling this way as well. Especially having entered the hobby on the tail end of things (“Joined: 01/11/2018 - 22:23”). What’s particularly striking to me is that my SC62w, a light which was released in August of 2014, is one of my most carried EDC lights. Also, the obsession with the Nichia 219B LED, which (from some googling) seems to have been introduced at the end of 2012.
I’d love to see some improvement in LEDs besides lm/W. Higher intensities, better beam profiles (I’m looking at you, Cree), better tints (less green, thanks), better CRI. I want higher efficiency too, of course. But I’d like to have to compromise less when choosing an LED.
I’d also love to see improved driver design, particularly in the enthusiast/DIY space. And by this I mean moving away from 7135s, and ideally linear drivers altogether imo. We’re already making progress on the first with the constant current FET stuff and looking into alternatives to the 7135, and the latter is definitely within our reach as a community (see: lume1). Certainly manufacturers have been doing great things with drivers (Wuben TO50R’s driver is amazing, but also all the bucks/boosts/buck-boosts out there).
Improved user interfaces is also a good goal. Enthusiast interfaces are already pretty excellent. Manufacturers… don’t understand, a lot of times. IMO, there are some fundamentals for anything with an e-switch: Give me a shortcut to the lowest mode (starting there every time works, too). Give me a shortcut to the highest mode. And don’t make me go through anything higher (or blinky) than the mode I’m trying to get to (because I will be blinded). Everything else is extras (and often, very nice extras) but those are the fundamentals I need on any of my lights that are anything close to an EDC.
Other than that, it’d be cool to see a somewhat expanded “standard range” of flashlights. We recently saw a lot more brands pick up some sort of right-angle light (Sofirn, Convoy, Jaxman) but I think T-shaped headlamps are cool too (Boruit, Sofirn, Acebeam, Nitecore - I guess I’m using “T-shaped” a bit loosely, but generally headlamps where the LED is in the middle of the tube). When I think about the basics, I come up with: tube light with tail clicky, tube with side-switch, new tail e-switch stuff, L-shaped, “T-shaped”. Then there’s true tube lights, pocket throwers, bigger throwers, single-emitter and triple/quad stuff. Mix and match as you please. I think we’re finally starting to get a good variety of all that stuff, but we still haven’t hit the point where there’s an option for everyone without some modding involved.
I also realize that some of the remaining ways to “improve” flashlights begin to make them difficult to mod. Zebralight is a good example of a few different features: unibody light for heat distribution makes it tough to get in the bottom of the head. Making things compact tends to make them harder to disassemble. And the driver/MCPCB combo makes everything related to either of them difficult to impossible (LED swap, driver swap, etc.). DQG also focuses on being tiny, and that also ends up being extremely hard to mod. Potting anything for durability tends to reduce mod-ability. Gluing things for increased IPXX ratings, soldering (or alternatives) things together for heat dissipation, etc.
The problem there is how throw scales. Because throw is related to the square root of candela, you need to quadruple your light intensity to double your throw. So while a mile of throw might be about 650kcd, two miles would be about 2.6mcd. The other problem is optics - throw is also directly related to the frontal area of your optics (and therefore to the diameter of the optics). So, you take the largest diameter light you can live with and the highest intensity light source you can find and you get what you get. Two miles seems reasonable to achieve with LEPs and throwers of acceptable sizes (smaller than GT), and maybe some additional advances. Four miles would be over 10mcd… and I think that will probably remain in the realm of Enderman types and maybe stuff that’s GT-sized if we’re lucky.
I think the battery tech field is extremely exciting. I’ve been getting teased by headlines about the replacement for Li-Ion since before I personally owned anything with a Li-Ion battery. I have to think that sooner or later, one of these things will eventually make it through the gauntlet and be commercially viable. Every electronic industry imaginable wants this, so there’s a lot of money driving this one. Should be a pretty good show when it does happen, as far as patents and Chinese copies and all that fun. I still remember a guy running an iPad off a thin metal-looking battery that he proceeded to cut with scissors while the iPad continued to run. I wouldn’t mind safer battery tech either.
.
That is a very accurate statement. :+1:
And some of my experiences so far too. I favor throwers and now see their limits. I was going to put the 90.2 in the water cooled light as that was the reason for building it in the first place. But after seeing Matt’s video, I like the 70.2 better. So if the 90.2 kit comes available, it will go into the MT07 Buffalo that has a bigger reflector than stock and big copper heat sink. I like modding and building and will continue to do so, with the understanding of being content with 1 mile throw.
.
Here is the specs on a WW2 search light. So 800,000,000 / 28 miles = 28,571,428 per mile. So our efficiency today is pretty good.
Light Source: 1 inch Carbon Arc (no light bulb!)
Power: 78 Volts @ 150 Amps
Candle Power: 800,000,000 (800 million)
Effective Beam length: 5.6 miles
Effective Beam visibility: 28~35 miles
Glass Weight Totals: 75 lbs
Brass Rhodium Coated Mirror: 180 lbs
.
I agree.
A few years ago I went around reading everything I could find on user interfaces for a single e-switch, on enthusiast forums around the world. I wanted to find out what people considered to be ideal.
What I found was, to a surprising extent, people mostly had the same basic design in mind. And that design is what I consider the “fundamentals”. Details varied a bit, but almost everyone wanted the same basic features:
From off:
- On (low)
- On (high)
- On (mem / med)
While on:
- Off
- Up (more light)
- Down (less light)
- Shortcut to/from max
… and most people also specified that the “off” action should be 1 click. … and that the other actions should be 2 clicks or less.
And most people wanted a couple extras too, like the ability to check the battery charge or lock the device for safe carry.
I consider this sort of a universal core at the center of e-switch UI design.
You know, a lack of major remaining LED advances doesn’t bother me. The lights that I already have do everything that I need them to, leaving me wanting for nothing.
My Nitecore TIP, for example, gives me as much light as I have ever needed from an EDC light. The ~1,000 lumens from my old Wizard Pro gives me enough light that I can go from Texas mid-day sun to digging around in a dark engine bay without needing to wait for my eyes to adapt. I have multiple throwers so bright that it’s the “light saber effect” that prevents me from seeing what I’m pointing the light at - not a lack of illumination. And with the vast majority of my flashlights, I never even run them beyond ~200 lumens (even though they can go much higher) to keep from obliterating my night vision.
While more efficient emitters won’t provide another giant leap forward in terms of maximum output, the increase in runtime can still be noticeable. Doubling run time from doubling efficiency would be quite a difference in practice. That said, onboard USB charging has taken away most of the inconvenience of recharging batteries, so I would need to see a pretty big improvement in run time before I start buying more new lights again.
Sort of like going faster in a vehicle. It’s not too difficult to go 150 mph, in a relatively aerodynamic car (not truck) it takes about 250-275 hp. However, after that your hp requirement increases quite a lot. To go 200 mph (50 mph more) needs another 300 hp! You’re talking 700+ hp for 200 mph. That’s not difficult thanks to turbos, big engines etc. but not cheap!
I found the original post pretty interesting, and couldn’t hold to talk about HEAT, buy I’m proud u/lightdecay did the math and talked about it better than I could.
More efficient leds not only mean more lumens per watt, but (of course) less heat per watt.
If we had 200lm/W led at higher currents, it would be reasonable to have a 10.000lm turbo D4V2 (considering a 15A/ 50W 18650).
Not only that. If the combo of led/driver produced 3 times less heat, it would probably give not only bursts of 10K but 2500/3000 stable lumens. That would be awesome.
Also, imagine a AA/14500 size flashlight with the same specs of 2021 SST20 4000K D4V2.
*We will see these things before the end of this decade. *I’ve just seen that my user in this forum is 12y old. Back in the day we were modding Maglites from incan to LED, and the big jump in technology was from a CREE P7 to XM-L. Most 18650 flashlights were around 500/700 lumens for a few minutes, and moving closer to 1000 was a dream. High CRI leds wasn’t a thing and some people still used incan P60 dropins for this matter.
I agree that there is not another LED revolution ahead, but things are going to be brighter and cooler (no pun intended).
The small revolution we are living now are software based flashlights, thanks to ToyKeeper (I’ve just realized that the creator of Holy Anduril was a real person and user in this forum, instead of something that came from some anonimate corporation). So, thank you very much. You are making happy people from all around the world, including a random real estate agent from Argentina like me.
The next revolution will probably come from batteries. We have been reading about new magical chemistries from a lot now, but at some point they will land in the market and provide new energy densities, discharge and voltage ranges.
Parameters, perceptions, and perniciousness.
I have photographic evidence of several lights impact on a target almost 2 miles distant.
Perhaps focus may be better applied to more applicable range and purpose. I hear there is a challenge in the works…
The only stuff I’ve got that can do that is called a “pointer” not a “light” so I’m kind of jealous
ABSTRACT
As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and—to a lesser extent—the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of
250–370 lm/W.
This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.
REFERENCES
https://aip.scitation.org/doi/10.1063/1.4721897#:~:text=We%20find%20that%2C%20depending%20on,250%E2%80%93370%20lm%2FW. of white light