SF KL3 head , requesting

Request user experience with kl3 Fresnel lense, and beam shots of kl3 frensnel lense.

Fresnel lense questions,
How does it compared to TIR kl3 throw
Advantage over a frensal lense copared to an TIR lense

Just wondering why surefire doesnt advetise on there site they have a frensal lense in there kl3 line up .

Thank you

fuzzy

I've got a KL3 on a SF9P.

By fresnal lens, do you mean the newer model withe the concentric rings?
Looks like a filament bulb inside the lens.

Hi DownUnderLite were you describing this

http://www.surefire.com/maxexp/main.pl?pgm=co_disp&func=displ&strfnbr=6&prrfnbr=929&sesent=0,0&search_id=60184

then view larger image, and the fresnal lense is on the black marked head on the above linked image
Is that the type you have?
It does have the concentric rings as you describe.
I was told this is gen 3 of the kl3, with concentric rings.fact.


Cheers fuzzy

Just so it's clear, it's still a TIR optic. Just a modified one to the one that was originally used.

Al

Interesting, in SF web site pic of KL3, the black KL3 has the concentric ring, and the HAA does not.

Bill

Bullzeyebill said:

Interesting, in SF web site pic of KL3, the black KL3 has the concentric ring, and the HAA does not.

Bill

Click to expand...

It's as if they made a batch of the Black KL3's more recently.

I just purchased a black KL3 with the concentric rings from Steven at tacticalsupply.com (along with a KL4). It's the only KL3 I've ever used, so I've nothing to compare it to. It has a very tight, white beam with no sidespill at all. It's as if all of the available light is directed into a focused spot. I popped it onto a basic 6P original, and have decided to use it as my "what's that out in the yard?" light. It runs smoothly at full power for at least 4 hours on a fresh set of batteries, and doesn't "overheat" like the other high output Surefires. It did note on the paper that it was a 3-watt LED (prob. very well regulated), instead of the one watts that I think were in the Gen. 1.

I might have gotten lucky, but for the money, this is a great light.
Cheers,
V

"Just so it's clear, it's still a TIR optic. Just a modified one to the one that was originally used"
thanks for that info size 15 i wasnt aware of that .
So basically theres a lense change but still has TIR. Well thats a bonus.
And the new kl3s dont flare out.


Virgo
You mentioned there no side spill. I thought the frensal lense would have more side spill then the non frensal conterpart .

Interesting wonder why they frensaled it then ?

thanks all

Right, no sidespill at all on mine. Basically just a hotspot and a tight corona. I can turn it on and illuminate something without any scattered light in the room. It really is different from every other Surefire I've used.

Surefire's KL3 and KL1 do not use a Fresnel lens. A Fresnel lens is a flat lens, made flat by taking away the whole body of the lens.

The TIR used in the KL3 and other flashlights (Inova) is anything but flat. It's more of a cone with a convex base. The LED sits at the top of the cone. The idea is that the whole light from the LED is captured through total reflection on the sides of the cone and reflected into a tight beam.

Inova's TIR produces rings around the central beam. Fresnle lenses and the images they project appear ringy. Maybe that's where the confusion comes from? However, the rings of Inova's TIR optics have totally different causes than the rings from Fresnel lenses (which are essentially shadows).

elgarak said:

Surefire's KL3 and KL1 do not use a Fresnel lens. A Fresnel lens is a flat lens, made flat by taking away the whole body of the lens.

The TIR used in the KL3 and other flashlights (Inova) is anything but flat. It's more of a cone with a convex base. The LED sits at the top of the cone. The idea is that the whole light from the LED is captured through total reflection on the sides of the cone and reflected into a tight beam.

Inova's TIR produces rings around the central beam. Fresnle lenses and the images they project appear ringy. Maybe that's where the confusion comes from? However, the rings of Inova's TIR optics have totally different causes than the rings from Fresnel lenses (which are essentially shadows).

Click to expand...

I know nothing of lenses or teminology, but that sounds like an accurate description of my KL3, except that it seems as if the LED sits under the base of the ringed cone and the light is reflected towards the point into a tight beam. When I look into it, the "point" in closest to me and it gets wider toward the base, as you go deeper into the bezel. The LED's under that, right?

V

My description was probably confusing: What you're looking at the bezel end is the base of the cone, which bulges out to make a focusing lens. The whole thing looks like a cone with a half-sphere at the base. The half-sphere is the bezel side.

EDIT: I hope I'm not stepping on anyone's toes with posting this: http://www.audio-q.com/Lumileds/NX05.gif.

That's a drawing of a TIR-similar optics, except for the lens bulge on the front that both Surefire and Inova optics have. The hole at the bottom is shaped to accept the LED and guide all the light into the cone, where is total reflected on the side, so it can only get out through the front.

Surefire has a photo of their TIR on their page (from the X200A weapon light).

This Wikipedia article describes the Fresnel lens. The TIROS from Inova has rings visible from the front that make it appear like a Fresnel lens, but it isn't. TIROS lookes more like the above mentioned optics, though with a much longer cone.

So this is not frezel lense, It just simple has concentric cirlcles as appose to the prev generation of smooth lense

So releastically speaking there no much difference b/t the concentric circle lenses as apose to the smooth lense.

That means i shouldnt care about the lense type on the kl3, thus makes no difference if its a generation 2, or 3 kl3, as theyll produce the same effect of TIR

elgerak,

thanks for that informative post. my KL3 looks like a cross between the two pics. (the Surefire TIR and the Fresnel lens on the Wilkipedia.):thinking:

Lets see various SureFire TIR optics from Shelby Chan's perspective:

Size15's, really neat pics of TIR optics. I think there is some confusion about the newer KL3 TIR optics. Somehow we are calling them Frezel lens, when they are concentric circles around the TIR. We are led to believe that these circles are supposed to spread the beam out more for more "spill", and yet one poster says he sees no sidespill with the newest KL3's. Looking at the picture of the black KL3 on SF's web site, the rings would seem to have a "Frezel" effect on the beam, and would indeed spread the beam out to some degree, compared to the non "ringed" KL3.

Bill

The KL3 beam (old version) does have spill compared to the X200A, and the KL3 beam (current/new version) increases the spill, but, neither has spill in the sense of "surround beam" that we see for a reflector. It's a matter of opinion and expectation as well as having various other flashlights to directly compare against. It's all relative is what I'm trying to say.

Thanks for the info guys. Mine is the black with the TIR optics and the rings. Like Al said, I'm comparing it to the other Surefire LEDs that I have available, all of which have significant spill. (L2, 1st Gen. KL1, new KL4). My expectations are probably different. This is the first Surefire I've owned that you could shine next to a sleeping person's head in a dark room, without waking them up or lighting up the rest of the room. Also, the throw is really impressive for my LED expectations. It's also not so bright that it blinds you with closeup use.

Cheers,
V

My KL3-BK with concentric rings arrived yesterday and it's quickly become my favourite combination on a G2 with a T6 clickie tailcap.

I could not believe the amount of light coming out of it, considering that it's quoted at only 19 lumens. At less that 1 feet, the beam profile shows a series of concentric rings around a rather squarish hotspot. These are not a problem in actual usage though. I found there's enough sidespill to make it a general-use light for walking and checking things outdoors.

Some eye candy.

Great topic!

I got a new version KL3 with rings last week from Lighthound and I think that it has a very tight beam, no sidespill at all. It makes a not very good light to use as "walk around".

I also have a G&P 3W dropin that puts light into a much bigger area, making it a better multi-purpose light.