Musings On Brightness

(Posted over here on The CandlePowerForums...)

Spill light is always a tough issue because IMHO the human mind isn't very good at translating between area coverage and equivalent overall output. Think of the photons coming from a light as water sprayed over a garden using a sprinkler... how much ground do you want to cover? You've only got a finite quantity of water. Let's further assume the garden is circular to approximate the shape of a typical flashlight beam. The area of a circle mathematically is Pi times the radius squared... that means a circle of twice the diameter will cover FOUR TIMES the surface area... and any given little plant in the garden will only have one-fourth as much water fall on it. Now translate water to light and it's easy to see that a light with broad sidespill (like many Luxeon-based lights, including the LuxV) could easily look dimmer than a light with the same output but a smaller radius of sidespill (like a typical Cree-based light). The reflectors themselves are typically optimized to focus light on a contained hotspot, so even a light with lesser overall output could achieve a brighter hotspot and therefore more throw.

What does this all mean? It's darned tough to look at two beams and tell which one is brighter! Add to that each person's individualized definition of what "brighter" actually means... for some it refers to throw... for others it's overall output... for still others it's intensity of the sidespill though not necessarily the radius of that sidespill (and we're back to that area coverage thing again)... it's not hard to see how one person could say light A is brighter while another could say light B is brighter, with both looking at the same lights!

Add to that the effect of tint variations and how those affect our ability to see objects of various colors, or see in clear air, moist air, fog, smoke, outdoors, indoors, pitch blackness, partially lit areas, with vs. without dark adapted eyes...

Then consider that the human eye is far from a universal device, that some people see some colors better than others... one person sees green well and blue poorly, for example, while another's vision could be just the opposite...

And consider that our light meters, even if they were 100% accurate (which none of them are) are calibrated to a perfect black radiator, meaning the SUN or in a lesser sense a filament-bearing bulb, which LEDs most decidedly are NOT, so some of the LED output may well be invisible to the meter, while other aspects of the light may end up getting overweighted in the meter's calculations... and how similar or dissimilar a particular LED's emission profile is to that ideal black body radiator will make it register better or worse on the meter even if it's really identical in brightness to the next one...

And we've got one heck of a problem to solve!

That said, the various attempts at clarity in this thread have been GREAT, and just the discussion of difficult issues like this can help everyone get to a better understanding, even if we may well never get to exactly the one, definitive, true answer, if there even is one out there at all.

Then as some have pointed out, the LuxV emitters in the U2 have improved over time, so some lights will show relatively better than others. Similarly, my understanding is that the P1D-CE may well be built using several different bins of Crees (P2, P3, P4, all in various tints) so they, too, will show relatively better or worse from sample to sample.

Will the best U2 outshine the worst P1D-CE? Probably. Will the best P1D-CE outshine the worst U2? Probably. What does outshine mean to YOU? I have no idea!

That's why IMHO the first thing to decide is what sort of light is most useful to YOU. It's not always an easy discovery, but the journey is a good one to take. Lights are after all tools and each tool will excel at some tasks while falling short on others. For me personally, I've long been on the quest for the ultimate trail walking light... I could fill ANOTHER post at least this long on what exactly that means to me, but I'll spare everyone that boredom here! In my builds I focus on EFFICIENCY and USABILITY, and have similarly detailed definitions of what those mean to me. In a way it's not a great set of design criteria since I'm trying to do this for a fulltime living... my lights typically aren't the brightest or the prettiest or the most extreme anything, really... and they're not the sort of things that wow folks at flashaholic gatherings... but they DO seem to be the sort of lights that grow on you as you live with them, the sort that you mildly like at first and come to love. Been fortunate in having a number of folks contact me to say one of my builds had replaced a formerly longstanding keychain companion, or pocket EDC, or kitchen counter light, or most-frequently-used light, or whatever. That sort of feedback makes my day!

But are my lights brighter than a U2 or P1D-CE or anything else for that matter? Well... that depends.

HDS CREEmation

A somewhat artsy logo I composited in Photoshop from several photos of an HDS CREEmated light. Kinda has that glossy gee-whiz catalog look! No, I'm not a Photoshop expert.

Lately I've started upgrading HDS U60, B42, and similar lights with Cree emitters. The result for a B42 can be dramatic: max output increases from 42 lumens to perhaps 84 and maybe even more. It's not the easiest modification in the world and certainly not a simple drop-in procedure, but I'm getting the hang of it!



The CREEmated B42 (left) owns a stock U60.

There's a post on CandlePowerForums over here with additional photos. I hope to do some more of these in the future.

Milky L1 Most Extreme Testimonial?

Had a purchaser of the Milky L1 write to me the other day about needing a replacement lens. This is a little unusual in that the lens is made from a tempered Pyrex glass that's 3mm thick and only about 22mm in diameter... would take one HECK of a jolt to damage the thing! So I offered the replacement and asked out of curiosity how the damage occurred... and proceeded to hear what might be the most extreme ML1 testimonial ever delivered. Here is his story!

I broke it!

Customer: "Just like I promised, I've beat the ever-living hell out of this beautiful little flashlight. And, happily, everything has held up to being banged, dropped, kicked, tossed, frozen and just about anything else you care to mention.

"Unfortunately I've managed to break the glass window around the edges - it hasn't fallen out, but the bezel ring (the thing that says "Caution - hot!" on it) makes an awful grinding noise when it turns, and this seems to be because of the cracked window.

"Where might I go to get replacement parts for this light? I remember you saying something about it being an "old-style" SureFire L1, so I'm not sure if Surefire would be the place to go.

"Thanks again!"

Me: "WOW!! You must be the first to inflict damage on a Milky L1. What the heck are you doing with the thing, hammering nails with the lens?"

Customer: "Well, good to hear I'm the trailblazer for broken lights! I think the damage was done when the light fell off a comm tower in weather about -15 F. It was 35ft in the air and either I or a compadre kicked it, and off it went. The only other damage is a tiny nick on the anodizing! I'm totally astounded."

MSaxatilus' "Wall of Light, Redefined!" Post

Good friend MSaxatilus over at CandlePowerForums.com posted some great photos of a serious short range flood light I'd created for a recipient in Italy... and shortly thereafter, CPF went down!

Thought Dave's post should get the exposure it deserves. The photos are IMHO terrific.


Wall of Light, Redefined! Introducing the Milky Mr. Big!
MSaxatilus from CandlePowerForums


Milkyspit has just finished another Surefire mod he has dubbed the Mr. Big.

It's basically a Surefire KL2 that has been modded with 3xWXOS emitters and three tiny McR11 reflectors.

The light is powered by 3xCR123s housed in a Vital Gear III body and produces a huge flood of brilliant white light. This is the ultimate flood light for its size. The throw is almost non-existent beyond 10-15 yards, but for close-up or indoor work, it can't be beat. Perfectly smooth beam and plenty of usable light.

Sorry the review is so short, but I figured I'd let the new owner post more details if he so desires.

Another fine job by Milky IMHO.

MSax

CR2-Ion CREEmated!

Okay, we all know the gold standard for finely handcrafted, smaller than all get-out lights was, is and shall always be the unfortunately named "Larry Light" (unfortunately named because Larry himself really dislikes it!)... or in the more recent world of small-run custom built flashlights, Modamag's nothing-short-of-astounding Draco. The CR2-Ion comes in a distant third to these lights.



Note the size compared to the handles on my linesman's pliers and a partially disassembled pack of DeWalt A123 cells... incidentally, those'll lead us to ANOTHER little project here in the labs!

Nevertheless, I had the opportunity recently to grab one of these via trade, and since I'd never seen one up close and personal before, I took the bait. The finish is a beautiful blue, which I'm told has since gone out of production... fit and finish aren't bad, in fact it's quite a clean build of good quality... mind you, not so ridiculously over the top as the Larry Light or Draco, but still quite nice. The emitter... ah, well that's where the problem is. I was excited to see my first light constructed around a Cree emitter, but the one used in the stock light is pre-XR-E, and while there's nothing wrong with it, the thing just leaves a nagging feeling that more could be done.

With inspiration from the CandlePowerForum's own 4sevens, a fellow modder who grew up alongside me in the modding ranks, and who I'm proud to count among one of my best of friends in this bizarre little corner of the universe, I decided to disembowel my little CR2-Ion to see if I could install my very own Cree P3-WC XR-E emitter... and a couple hours later, voila!



Look, ma, I'm a photographer! (Not really, more like got really lucky with 1 out of 20 photos.) I love these emitter closeups.

This thing really kicks! With no changes to the reflector whatsoever, the output looks to have doubled or tripled overall... and for the first time ever this light actually has a real, bona fide hotspot that really throws. Maybe it's not ready to take on a SureFire turbohead... still, quite an improvement! And I'm not so sure I'd want the turbohead on my keychain.



Upright next to a Mag 2C head, the CR2-Ion looks positively tiny... those 18mm reflectors inside the Mag head give me the same feeling as the photos one sees from time to time with an aircraft assembly worker standing completely inside the confines of a commercial jet engine!

SureFire M1 Dissected... and Upgraded!

I've been turning the SureFire M1 into a Project-M light dubbed the M90-M1 Illuminator, for a while now. Someone pointed out that it might be of interest to snap a photo of the disassembled light in that few folks have ever seen the guts. Here it is!



Some quick notes... the window is polycarbonate and press-fit tightly against an O-ring... the little black dot is an IR filter... the circuit board is a resistored IR LED with a spring on the underside... the items from circuit board (left) to IR filter and O-ring (right) all fit inside the body shown above the parts... threading on the tail end is SureFire C Series compatible, and threading on the head end is incompatible with any part that I've ever encountered... seems to be specific to this light, which actually does make some sense given the light was probably designed to be robust, self-contained, and permanently sealed.

Note there's an O-ring seal between body and head that ensures weatherproofness.

Now that the M1 is opened, what can we do with it?

A few things, actually.

1. M90-M1 Illuminator. LuxV white with reflector and glow ring, pumping out a bright, even illumination out to about 20 yards with a soft hotspot that lets you look at things up close (even in the palm of your hand) without hurting your eyes. Estimated output 90 lumens, estimated runtime on single 123 primary or rechargeable 60+ minutes.

2. M90-M1 Cyanator. LuxV CYAN (blue-green, aqua color) with reflector and glow ring, pumping out a bright, even illumination out to about 20 yards with a soft hotspot that lets you look at things up close (even in the palm of your hand) without hurting your eyes. Can help in finding things by virtue of changing the color response of objects... some things appear as blackish silhouettes, some things take on an eerie alien glow. Estimated output 90 lumens, estimated runtime on single 123 primary or rechargeable 80+ minutes.

3. M77-M1 Creemator. Cree white emitter with reflector and glow ring, pumping out a bright, even illumination out to about 20 yards with a soft hotspot that lets you look at things up close (even in the palm of your hand) without hurting your eyes. Estimated output 77 lumens, estimated runtime on single 123 primary or rechargeable 140+ minutes.

Some eye candy...













Which one do I like best? Tough question as they're all neat lights! Guess I like the Cyanator for its combination of good runtime, serious brightness, and otherworldly color... which is also surprisingly useful!

All three versions of the upgraded M1 (Illuminator, Cyanator, Creemator) cost $165 plus shipping built in your M1 host or $225 plus shipping with me sourcing the M1 host.