XM-L zooming flashlight with long zooming mechanism: improves throw?

Hi guys

As we all know, xml and zooming lights are not very good throwers due to big die size of the xml LED. OK, they require big diammeter lenses to throw well, or a very good desing of the lens...

I have spotted this flashlight at DX

http://www.dealextreme.com/p/w-878-xml-t6-5-mode-700lm-white-led-zoom-convex-lens-flashlight-w-strap-1x18650-3xaaa-2x26650-117766?r=43033281

Which seems to have a longer zooming mechanism than others...

How will affect that to the throw?

Well, the further the lens travels from the LED, the less of the radiated light it will be able to capture...

This is the reason why zoom-lights give far less light out when in spot mode (try ceiling bounce with bare eye, zooming in & out).

If the lens is really big, maybe some advantage.

Fran82, descriptions on DX, are getting worse and worse...

It says it can take 2*26650.

And it says it is 42*42mm, which I am sure is not true.

The longer the distance to the led in throw, the less light it can concentrate as Cheap Thrills already said, but with XM-L there are some models that are placing the die too close to the lens on flood, to get a really big one, which is good, so having more travel, doesn't mean the lens will be further than on other lights on throw, it just comes closer to the die.

OK, explanation understood

About DX.....

Depends on the focal length of the lens. the longer the focal length, the farther from the LED it needs to be.

And the less light it gets to focus.

Your average zoomie loses 50% of output at full zoom. This is a lot.

It still doesn’t affect throw however. The hot spot will just be smaller.

Agreed. But given an adequate focal length there might be more light in the hotspot.

Or might not....

Yes. With a shorter focal length the hot spot will be larger.

+1

we can assume full extension is fully focused, so with the (wide beam angle) xml, you'll lose a LOT but get a small hot spot. You actually might prefer that, even to larger hotspot that has higher lux, depending on your use....

I have a half dozen (models of) zoomies now, 2 are xml. I think of the xml as a flood light that isn't totally useless over 75 yards (because if you want to spot something you can focus it and get some more distance). I love the raw output.

The others are Q5 (at least claimed lol), and are primarily throwers, in comparison. I like 'em - they throw like crazy and are more useful to me than a dedicated Q5 thrower (but don't make me go WOW on flood).

OH - one more thing, whoever wrote that DX description was high.

I kind of like that!

Pros:

And it takes a 26650 battery.

An unobtrusive bezel.

Perhaps a very wide flood.

Push/pull zoom.

No flats to the body.

Good knurling (looks like it from from pics. YMMW I guess? )

Brass plunger on the aft spring.

Cons:

Unknown driver current since the 1500mA and the 700 lumens does not add up.

Monstrous greasy fingerprints on the lens visible in pics

Uncertainties:

The led looks off centre but that may be the lens+POV angle

I cannot decide if there is a air bubble in the lens or if it is a drilled hole in the retaining ring that I am looking at. Leaning towards the latter.. But?

A good light? Could be rather phenomenal at that price actually. Long runtime & decent output with really really wide flood and adequate throw is a real possibility it seems. If anyone reports back that it is even just decent I am pulling the trigger and buying that + 2 good protected 26650 cells. LOL

My wishlist is never getting shorter although I keep deleting the stuff I already bought! How can it be possible. I am sure I can illuminate a small city with all the light I have. It is a disease and the perfect do it all light is the cure!

I could add a Ledil TIR on the XML and make it a fixed thrower light, or change the emitter with a R2 and use the XML in another DIY project. But, if only we could know the dimensions of the star and the driver. I've seen 25-30mm stars lately in some lights.

It’s actually one of the two indents in the pill ring used for screwing/unscrewing the pill.