Emisar D4V2 & Noctigon KR4 w/ XP-L HI 2850K info needed

[CNR]

Hi all!

After a loong time of various troubles that kept me away, i'm on for a new light again.

I'm looking at one of the Emisar D4V2 and Noctigon KR4 as a medium floody EDC for short/medium distance illumination but i'm baffled with some of the choices and I can't find enough info, so if anyone know and can help me out please do

1. Does the pocket clip work in the D4V2 short 18350 body?
   
2. The Titanium (with copper fins) version of both looks awesome but is it possible that it will have lower performance due to poorer thermal conduction overall?
   
3. LEDs! I love warmish/neutral tints, I hate bluish or greenish ones.
   Hi CRI is not so important (though appreciated).
   I'm leaning towards the XP-L HI 4000K (70-75CRI I assume), having rejected the SST-20s from the fear of the low level greenish tint and the Nichia's due to the low output and heat issues that diminishes the useful output even more.
   But there is also the XP-L HI 2850K 80CRI for which I can't find any info on it's output, heat and power efficiency, does anyone know anything about it?

As I feel, I will probably get one now and schedule another one with Nichia 219B 3500K as soon as I can afford the experiment

Thanks!

 

[Showngo]

1. Yes, the clip mostly works with the 18350 body. As in you can keep it on, but it extends past the bezel. It still works, but it's not the prettiest setup.
2. Look at the LH351D. Or the Nichia e21as. Both are efficient and keep you away from the blue/green issue while giving you really high CRI (90 and 95+). If you want really warm both go to 2700k and are great, but even the LH351D in 5000k is a really clean whit light. I myself am a warm white fan and the e21a does that really well, you can even get it down to 2000k!

These lights come with the new dual channel tint ramping and channel switching boards if you want, so you could go best of both worlds. Get one with a warm set of LEDs and a cooler set, switch or mix between them. Great lights, super fun.

 

[CNR]

Thanks Snowngo,
I've read about the LH351D but unfortunately they are not currently offered as an option, the E21As indeed look amazing but the output is so much lower and combined with a relatively floody setup i'm afraid they will look weaker than my old Zebra SC600w.

 

[Connor]

1. The Titanium (with copper fins) version of both looks awesome but is it possible that it will have lower performance due to poorer thermal conduction overall?

Yes, Titanium is a very bad heat conductor and a poor choice for small high powered flashlights.
Also keep in mind that the copper head is untreated and will look really ugly (or beautiful, depending on whom you ask) really quickly. It will also feel much hotter and burn your fingers faster.

The SST-20 4000K 95CRI LEDs Hank sells are currently FA3 bin which should not be very greenish even on low and slightly rosy on high.
You can email Hank and ask for things like an illuminated switch or a 9A+FET driver in the D4V2.

 

[CNR]

....the copper head is untreated and will look really ugly...

Ugly? man!! Patina copper IS my favorite material/color
But do you know for a fact that the copper head isn't enough to keep the light (as) cool? For the copper head to feel hotter is good as it's a warning for me to step down before i fry my leds.
Otherwise i will go for the full copper model but i thought to change for once, since the TI-copper one looks so nice!

Now you're opening a new subject for me, i thought the driver issue was only about the Nichia drivers, not the SST-20 or the Crees, what is the 9A+FET driver and how's different than the one offered as standard (1+3+FET i think, whatever that means) ??

 

[purduephotog]

If it feels hot, it's moving heat from source to sink (your finger). Most people have never experienced this, but if you were to take a solid silver spoon in one hand, touch the head to an icecube, nearly instantly you can feel your fingers getting cold.

If the head isn't getting warm, all of that heat has to go somewhere- which means its cooking the LED.

General rule: 10sqinch /watt passive cooling. Obviously that isn't going to work so you'll just have higher deltaT.

I would take copper every day- possibly plated so it doesn't corrode, and an interference fit between parts to something less prone to abrasion for threads.

 

[CNR]

purduephotog: So you do believe that the Ti-copper will be stepping down earlier and it will sustain less lumens in extended use due to the less copper mass compared with the all copper one, right?
I'm afraid that this is true but i was wondering if someone had actually the chance to try it.

 

[Connor]

Now you're opening a new subject for me, i thought the driver issue was only about the Nichia drivers, not the SST-20 or the Crees, what is the 9A+FET driver and how's different than the one offered as standard (1+3+FET i think, whatever that means) ??

Hank offers several drivers now: FET+1 (standard), 5A+FET, 7.5A+FET, 9A+FET
It depends on your choice of LED what driver you can get, some need to have the FET output disabled or reduced as to not instantly destroy the LEDs.

I recently ordered a D4V2 with SST-20 4000K 95CRI FA3 bin and these allow for the 9A+FET linear driver which offers full regulation up to 9 amps and should have higher efficiacy/produce slightly less waste heat but you still have the full turbo power via the FET.

The field-effect transistor (FET) is a type of transistor that is used in electronics to switch high currents.

 

[CNR]

All right, so FET+1 is fully regulated (and hence power efficient) up to 1Amp current draw and from there on it's FET on direct drive.
But i believe what anyone would want is a fully regulated output up to the top of the ramp and a direct drive only on turbo, so why having drivers that stop regulating in less output (i guess 1Amp draw for 4 leds must be lower than the middle of the ramp) ?
what am i not getting right here?

 

[Connor]

FET+1 is only regulated to 350mA and hence not very power efficient.
Some of the LEDs (e.g. E21A) cannot take more than the 5A driver outputs and FET has to be disabled too because it would burn the LEDs in seconds.
For the SST-20 the 9A+FET driver is almost what you are asking for, fully regulated except turbo and a few of the top ramp levels (where the light overheats in 10-20secs and has to ramp down anyways).

 

[CNR]

all right, so if you have, for example, a 5A+FET driver then above 5A draw you are wasting energy by "regulating" current through impedance, i.e. turning the excess of the power your light needs to heat.
so i have to know the amperage of my chosen leds at various levels to ask for the appropriate driver.
Thanks

 

[Connor]

I'd suggest asking Hank directly via email or to check some of the BLF threads about Emisar lights.