Can't decide between a U2 and Kroma...

First of all, are the heads the same diameter? But I'm selling some wares and I am considering picking up a U2. Or a Kroma. Can't decide! The U2 is rated higher at 100 lumens but is reflectored (which I like mind you) and the Kroma is rated at 50 lumens but is an optic (which I also like) Also I don't really know if I will actually use the red and blue leds' in the Kroma. I kinda wish they were white. I like that the Kroma is a LuxIII. The concern I have with the U2 being a Lux5 is of course the donut hole and tint. I think I'm just going to bite the bullet and get one and hope for the best. I guess I'll have to think about this some more. I'll be putting up a L5 w/ new GenIII KL3 head up for sale here soon to help pay for it.....decisions, decisions.

I don't have a Kroma, and the main reason why is that I just can't figure a practical use for selectable red, blue, green, IR or UV LEDs on a light. Don't get me wrong, it's a great idea with uses for some people, but for a civilian like me the U2 is the way to go. It's bright/floody when you want it and dim/floody when your eyes are already adapted for the dark.

I own about 85% of the Surefire catalog and my two most-used lights are the U2 and an L5 with an incandescent Turbohead and clicky tail switch.

Just ask what you need it for. Throw? Flood? Good run times? Red lights? The Kroma has a bigger head, btw.

I personally have a U2 and it makes more sense for me than the Kroma. The only thing the Kroma would offer me is a neat red/green light to use at night, ie a Low setting that is lower than the U2's low.

scott.cr said:

I don't have a Kroma, and the main reason why is that I just can't figure a practical use for selectable red, blue, green, IR or UV LEDs on a light. Don't get me wrong, it's a great idea with uses for some people, but for a civilian like me the U2 is the way to go. It's bright/floody when you want it and dim/floody when your eyes are already adapted for the dark.

I own about 85% of the Surefire catalog and my two most-used lights are the U2 and an L5 with an incandescent Turbohead and clicky tail switch.

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I'm in this situation as well. The Kroma seems to be made to do everything, but maybe not everything very well.
The Kroma mil-spec was tempting, but I don't have NVG anymore, blue and green seem good only for very special uses. I have a much brighter UV-light than the Kroma could be and it isn't that large either.

I looked at the beamshots and really prefer the beam of the U2. Mine has the best tint of any led I own, although some would not like the warm white tint.
If I need red light I usually have a red Photon on the lanyard, and I have a FM-65 red filter/lens protector for the U2 as well.
If SF had made the U2 with a HDS like lowest in HA-nat it would be perfect.

KDOG3: Didn't you consider the U2 before buying that L5? It seems it is time to come over to the dark side...

Sverre

scott.cr said:

I don't have a Kroma, and the main reason why is that I just can't figure a practical use for selectable red, blue, green, IR or UV LEDs on a light.

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Hi there; the Kroma MILSPEC uses White, Red, Blue, Yellow/Green and IR LEDs, not UV. Yellow/Green, at about 550nm wavelength permits many to remain night adjusted to see instrumentation and various astronomy activities, although you'll probably use the Red LED for that. Most UV LEDs are closer to 250 ~ 350nm. Did you know that most Black & White surveillance cameras are optimally sensitive to near-invisible IR LEDs at 850nm? That means you can put an inexpensive B&W video camera in a sleep center hospital room, turn on the Kroma MILSPEC, and observe the patient undisturbed, but fully illuminated.

Of course, if you suspect someone's raiding your backyard shed for mulch or firewood, the Kroma MILSPEC will light 'em up and they won't know it!

Here's a typical (not Surefire's) LED wavelength chart.

KDOG3,

The U2 is definitely the light if all you need is white light. It is far more versatile, more powerful, has a more useful beam, and can be "skinned" with the F-70 "slimline" beamshaper or the FM-64 larger version.

Both heads are 1.47" in diameter and will take the F-70/FM-64 filter families. The Kroma is slightly shorter because the optic in the head does not require the "length" of a reflector to function. An optic-controlled beam allows for a more truncated housing.

The only advantage to the Kroma is the gain in low/high "RED" for night-vision and night-navigation, and the low/high "BLUE" for blood-trail tracking in a hunting capacity. The low/high white function will be FAR more limiting in the Kroma than the U2. The primary use for the Kroma, as I see it, is as a wiz-bang, do-everything, hunting flashlight, and that is why I have p[urchased it. I do not yet have it in my hand for a comparison but will publish here when I do. I also purchased a Kroma-MilSpec, more out of curiosity and as a comparison than for expected usefulness.

Hope this helps,
Flashdark sends.

Yeah, I don't really see a need for the Kroma other than Wow neato effect. I think I'll try the U2, I gotta see what all the fuss is about. I just gotta keep my fingers crossed for a good tint and no donut hole.

Loomy said:

Just ask what you need it for. Throw? Flood? Good run times? Red lights? The Kroma has a bigger head, btw.

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Hi Loomy,

I myself owna Kroma Milspec and my friend owns a U2, and the Bezel Diameter on each is 1.47 inches.

The Kroma head is also a little bit shorter in length. That difference in pictures can make the Kroma Bezel seem wider when that is not the case.

Mind you, the PKEF experimental Light that some own do indeed have a larger Bezel.

Hope that helps,
John

Thanks for the correction John

I have both the U2 and the Kroma with the red / blue LED's. If I had to choose between one or the other, I would pick the U2 as it is simply a scorcher on high, has multiple lower levels that are very useful and an extremely long running low level that is surprisingly useful.

Regarding the Kroma, it does everything that it is advertised to do very well. The beam quality on every setting is excellent and the levels are all very useful. I would choose the Kroma over the A2 also; by the way and I hold the A2 in very high regard it is just that I prefer the longevity, runtime and levels of LED's to the incancdescant beams.

When I finally bring the Kroma hiking, I will see how useful the red is to me... I can't really see the use for blue as I don't track blood or look for fluids. If I ever get to use the blue,I you can believe that I will tell you about it.

I am truly very happy about having the Kroma even though I believe the U2 is a better general purpose light.

-Goatee

I would'nt buy a LuxV light for that money, because the lifetime is rated for only 500 hours.

Best regards

____
Tom

I voted with my wallet on this one and preordered a Mil Spec Kroma because I think the Kroma might replace multiple A2's. The only low level I have no use for on the Mil Spec Kroma is the IR, but since it will take a while for the light to arrive I might figure out a use for the IR beam while waiting.

Richard

I might buy a U2 sometime, don't know for sure though. I did just purchase a couple of Kroma's though, should have them tomorrow.

:)> said:

...I would pick the U2 as it is simply a scorcher on high, has multiple lower levels that are very useful and an extremely long running low level that is surprisingly useful...

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I agree, my U2 is tremendously bright. Simple lux meter reflection tests indicate it's putting out about TWICE what my HDS U60 does, which in theory is 120 lumens.

You take a risk with the donut beam pattern, but Surefire will replace it if you don't like it. My first U2 had a really severe donut pattern, like a smoke ring visible at all output levels, distances and surfaces. My replacement has a faint donut pattern I can live with.

The U2 low level should really be dimmer -- it won't fully preserve night vision. However it's a powerful, flexible light with a good balance of flood and throw that does many things well.

If Surefire had made the Kroma with only red LEDs or a mix of red/white (essentially an improved A2) I'd be interested. But I don't need to track animal blood at night with mandatory blue LEDs.

Long John said:

I would'nt buy a LuxV light for that money, because the lifetime is rated for only 500 hours.

Best regards

____
Tom

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What?:huh2: Is this true folks?

Long John said:

I would'nt buy a LuxV light for that money, because the lifetime is rated for only 500 hours.

Best regards
Tom

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What is the concern? Surefire warranty.


Even so, the price of putting a new emitter is pretty cheap, about the same as a regular SF incand bulb. I wouldn't be too concerned.

I don't have either one of these lights but If i could, i would have the Mil-spec Kroma over the U2 anyday. The U2 may be brighter than the Kroma,..but then again my M3 Turbo is brighter than the U2 - so for me the KROMA's versatility & fun-factor are what seal the deal.

Luna said:

What is the concern? Surefire warranty.


Even so, the price of putting a new emitter is pretty cheap, about the same as a regular SF incand bulb. I wouldn't be too concerned.

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About the SF warranty there are different angles for viewing. At the moment I wait more than 2 months for a simply switch, but that's another theme.

Normally a Led is not a case for warranty claims, except the light is new.
The problem here is, the user can't easy open the head to change the Led by himself. If so, I would'nt not extremly concerned, because the price for a new one after this 500 hours is'nt a big problem (by doing yourself).

If you will have to pay for it by SF, incl. shipping 2 ways, perhaps different continents, it would be a problem IMO.

But one important thought not to forget. If you use the light in situations, where it's not so important to have a reliable light, you can think your way.

But when I have to pay such lot of money for a light (about 380,- Euros here), 500 hours are far too little for me, not to forget, to the end of the lifetime the output will get dimmer and dimmer.

Best regards

____
Tom

Long John said:

Normally a Led is not a case for warranty claims, except the light is new...But when I have to pay such lot of money for a light (about 380,- Euros here), 500 hours are far too little for me, not to forget, to the end of the lifetime the output will get dimmer and dimmer...

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I think Surefire's lifetime guarantee covers everything except bulbs and batteries, over the entire lifetime of the light, no matter how long that is.

BTW where does Surefire state the U2 emitter life is 500 hours? I can't find that anywhere. I see for certain versions of the Luxeon V emitter, Lumileds says the lifetime is 500 hr. Two comments about that:

(a) How do we know the U2 uses that exact emitter version?
(b) Even if so, if Surefire doesn't mention an emitter life and warranty exclusion for the U2, it's a covered item.

It's no different than the tail switch. Tail switches don't have infinite life, but Surefire will replace that under warranty, not say "you wore it out".

Has any owner of any Surefire LED light ever "wore out" the emitter and been refused warranty coverage? Isn't this a purely theoretical concern which has never happened (nor likely ever will happen) in the real world?

If you haven't checked out this thread by "curse", which has all the Kroma beamshots you could ever ask for, especially comparing it with the U2, you should check it out!

It made me happy I own a U2, and that I didn't preorder the Kroma... unless you need the different colored lights (or perhaps plan to mod all the colored lights to white, if that's possible), go for the U2. You'll be hard pressed to find one without a donut - I've owned three, and only one hasn't had a donut, but it had runtime issues... but it's not that bad.

john