I got bored.

[fyrstormer]

If idle hands are the devil's workshop, then I must be the devil. :devil: You all may remember me recently posting this:

Well, now it looks like this:

Can you spot the difference? Here, let me clarify:

Yes, that's a brand-new Luxeon K2, 220lm @ 3.7V x 1.5A. Here's what the beam looks like:

The hotspot is as warm as it looks -- warmer, actually. If I'd had any sense I would've taken a beamshot of the Seoul P4 that used to be in there, but I'm sure there are plenty floating around already. Here's a comparison to a Cree R2 and an OSRAM Golden Dragon, in that order:

So...two big differences I notice:

1. The Luxeon is much more focused, resulting in a much more defined hotspot, though the spill is by no means dim -- this IS one of the brightest single-die LEDs on the market, after all.

2. The tint is so much warmer that at first I thought I'd made a mistake when I ordered the LED; having specified neutral white, I thought I got warm white instead. This thing is warmer than absolutely everything else I have, even the prototype "V0 bin" P4 in the McGizmo PD-S I bought a couple of months ago, which Don described as a "warm brass tint." So it's probably not so great if you're still enamored with the dazzling bluish light from older LEDs.

The color difference is so great that I also thought it was dimmer than the P4 at first, but that was in a brightly-lit room. This being a flashlight, after all, what matters is the light quality in the dark, and outside at night it is readily apparent that the Luxeon is brighter and the warm light is much better for seeing in the dark.

Would mod again.

 

[Gransee]

Nice pictures and description fyrstormer. Lots of questions. Did you do the mod yourself? How long did it take? Would you describe it as "quite difficult", etc? Where did you get the K2?

Looks nice!

peter

 

[TranquillityBase]

Great mod!

I am currently hooked on the Cree Q3-5A, Do you have experience with the Q3-5A, and if so, what's the primary difference between the two LEDs, color rendition aspect?

Thanks,
Scott

 

[tebore]

What's the bin on the K2? Where did you order it?

 

[AMRaider]

Cool mod!

...1. The Luxeon is much more focused, resulting in a much more defined hotspot, though the spill is by no means dim -- this IS one of the brightest single-die LEDs on the market, after all....

I have noticed this as well when comparing the K2 TFFC Arc6s with the Seoul P4 Arc6s.

There are plenty of larger lights out there with good throw, but not as many smaller lights with good throw. I find throw to be very useful for my needs (easier to illuminate objects at a distance), and I like the portability of smaller lights. It is for that reason that I prefer the K2 TFFC in the Arc6 instead of the Seoul P4. In the Arc6, the Seoul P4 projects something closer to a "wall of light", while the K2 TFFC definitely has a tighter and more defined hotspot. I'm sorry, but I have no beamshots .

 

[fyrstormer]

Nice pictures and description fyrstormer. Lots of questions. Did you do the mod yourself? How long did it take? Would you describe it as "quite difficult", etc? Where did you get the K2?

Looks nice!

peter

Wow, I got Peter's attention.

I got the K2 from here: http://www.futureelectronics.com/en...tters/white/Pages/9138751-LXK2-PWN4-0180.aspx

This outfit sells lots of LEDs and other electronics, but not all of them are available for sale on an individual basis. I got lucky and the 250lm (brighter than I remembered!) neutral-white K2 was available in small quantities, so I bought two. Only needed one though, but if I bought one I would've needed the second. You know how these things work.

The mod was not overly difficult, but it was time-consuming to remove the P4. The white epoxy you used held very strongly; I know Arctic Silver recommends mixing their conductive epoxy with some regular heatsink paste if non-permanent adhesion is desired, so you might want to consider trying that in the future. I ended up destroying the P4 trying to take it out, and then I had to use a router tool on my Dremel to chew away the remaining epoxy. Not that I blame you for any of that, I fully expected to have to do that.

I also had to remove a bit of the bulkhead near where the black plastic electronic bit sticks through it (whatever that thing is), because the new LED is square instead of round. That was actually easier to do than removing the epoxy, for some reason. All in all, it took about an hour and a half to finish, including replacing the wiring, which was impossible to salvage due to being glued to the old LED.

In any event, there is now a distinct difference in tint between the various settings on the light, so I'm thinking of sending the whole thing back to you to see if you can recalibrate it, and maybe cool off the tint a bit. Does that sound feasible?

 

[fyrstormer]

I have noticed this as well when comparing the K2 TFFC Arc6s with the Seoul P4 Arc6s.

I didn't know there were any Arc6s with K2s in them. Did I just reinvent the wheel?

 

[fyrstormer]

Great mod!

I am currently hooked on the Cree Q3-5A, Do you have experience with the Q3-5A, and if so, what's the primary difference between the two LEDs, color rendition aspect?

Thanks,
Scott

I got a Lummi Wee with a Q3 in it, and I'd say the color rendition is virtually identical to the K2. Which is to say, I couldn't tell a difference.

 

[AMRaider]

I didn't know there were any Arc6s with K2s in them. Did I just reinvent the wheel?

When they were first released about a year ago, the Arc6 had a factory installed Luxeon K2 TFFC (Update: Mfr Part# is LXK2-PWC4-0200). Soon after the release, Arc switched to the Seoul P4 (W42180-U2SW-OI at one point) due to the K2 TFFC's lack of availibility.

There's a few (long) thread's on the Arc6 here on CPF, but you might have to dig a little to find them.

 

[Gransee]

fyrstormer, we can recalibrate it for you no charge. Just send it in with a note.

The K2s used in the Arc6 limited run were cool white 200s. The link you provided is to a neutral 180. The P4s we are using are between the 180 and the 200s in efficiency.

Nice to hear someone swapped the LED and it took a reasonable amount of time. Better than just buying an entire flashlight everytime a new LED comes out. The mod probably cost you less than $20.

Btw, if you want, we can include a reflector optomized for the K2 with your service request. You can then try both reflectors and see which one produces the type of beam you want.

peter

 

[fyrstormer]

fyrstormer, we can recalibrate it for you no charge. Just send it in with a note.

Will do.

The K2s used in the Arc6 limited run were cool white 200s. The link you provided is to a neutral 180. The P4s we are using are between the 180 and the 200s in efficiency.

I guess that's inevitable, since the cool white LEDs are always more efficient. I like the warm tint of the K2 I installed, but it doesn't pick up the bright green in foliage as well as the cool white LEDs do.

If there's a way to crank up the voltage to get a bit more blue to punch through the phosphor without damaging it, that would be ideal. I think the red and orange content of the light is pretty much perfect as-is. From what Curt at Peak told me, the K2s are much more resilient than the P4s are, and he said he ran a K2 at 50% higher current than he was supposed to with no ill effects.

Nice to hear someone swapped the LED and it took a reasonable amount of time. Better than just buying an entire flashlight everytime a new LED comes out. The mod probably cost you less than $20.

Including the spare LED, not including the soldering equipment which I've been using for years, it cost less than $10. I don't think they even charged me for shipping.

Btw, if you want, we can include a reflector optomized for the K2 with your service request. You can then try both reflectors and see which one produces the type of beam you want.

peter

That would be fantastic.

 

[fyrstormer]

Mailed on Tuesday, Priority Mail. Should get there by the end of the week.

 

[TranquillityBase]

Just fired a few K2's up, they sure are warm! My old favorite Q3-5A Cree light, looks bright white by comparison.

Thanks for the link!

 

[fyrstormer]

Holy crap Peter, you turned my Arc6 into a flamethrower! My initial impression after installing the K2 was that, while it may have been a bit brighter and more tightly focused, the tint was so warm that the extra brightness was largely lost to my eyes, which seem to prefer the tint of a cool-neutral Cree Q5 out of all the emitters I've seen so far. But with whatever calibrations you made, the tint is much cooler now, and the output is much higher besides (again, according to my eyeballs).

Did you happen to compare it to a stock Arc6, by any chance? What were your impressions? Also, did you install the K2-optimized reflector that you offered to provide before?

 

[Gransee]

I am sorry. I didn't know which one was yours. Did you attach a note about the reflector? Send me an email with your address and we will ship you the reflector.

peter

 

[RAGE CAGE]

Holy crap Peter, you turned my Arc6 into a flamethrower! My initial impression after installing the K2 was that, while it may have been a bit brighter and more tightly focused, the tint was so warm that the extra brightness was largely lost to my eyes, which seem to prefer the tint of a cool-neutral Cree Q5 out of all the emitters I've seen so far. But with whatever calibrations you made, the tint is much cooler now, and the output is much higher besides (again, according to my eyeballs).

Did you happen to compare it to a stock Arc6, by any chance? What were your impressions? Also, did you install the K2-optimized reflector that you offered to provide before?

looks like you could be the next custom modder on CPF- nice work!:wave:

 

[fyrstormer]

Mine was the one with the weird clip and the O-rings wrapped around the battery tube. I'll send you my address in a minute.

The K2 using the P4-optimized reflector has a very distinct delineation between the hotspot and the spill, with virtually no fade between the two. How does that compare to the beam pattern of the K2 with the K2-optimized reflector?

Nah, I'm not likely to be the next big custom modder, at least not of Arc6's; I just don't have the hardware necessary to reprogram them, nor to measure and calibrate the output.

The tint of the neutral-white K2 that I linked to, when properly calibrated by someone who knows what they're doing, is definitely a worthy mod however. Having seen the recalibrated output, I would definitely mod it again.

 

[fyrstormer]

I got the K2-optimized reflector a couple of days ago, and installed it. The effect was actually the opposite of what I was expecting, but it's still good. I was expecting it to broaden and soften the beam, to make it more like what the SSC P4 produces, but instead it took the somewhat broad and hard-edged hotspot from the K2 and both tightened it and softened the edges. The softer edges around the hotspot are a plus in any event, and I suppose given the warm color of the K2 I installed, having a concentrated hotspot is better for seeing at a distance because the light isn't as brilliant as it would be coming from a cool LED. Which is not to say the spill is useless by any means; it's definitely still useful, despite not being as bright as the spill from the SSC P4.

All in all the K2 with the optimized reflector is a good way to dramatically increase the throw of the Arc6 without substantially sacrificing peripheral lighting.

Oh, and the casing definitely starts heating up faster now that the LED is attached using Arctic Silver epoxy instead of whatever the white stuff was. (probably zinc oxide, but I don't know for sure.)