Nice to see the XR-E is still being valued. Despite my small collection of T6 emitters, I still like the R2 in my Solarforce L2, and I have four more of those emitters for a flashlight hack I have thought about for months, but haven't even started yet.
I like my XR-E R2 flashlight a lot. It's just a P60 host but it is a perfect amount of light for a general purpose light.
Which is why I may have to avoid DX and Manafont for awhile, and save my loose change until I can afford one of the new Fenix Tk41.
Looks like they may have optimized the XM-L for throw on that thing, it is about the size of an old-fashioned 2C-Cell light. They claim it throws 450 meters or so. Not a budget light (by my standards) but may be the best photon blaster on the market short of going HID. Can't wait for the reviews...
I would like to know if ANYONE has tried using a XML emitter in the Uniquefire HS 801/802 body! I found people posting they are going to try it but no one has ever posted the results. Based on my limited knowledge of throwers, the actual thowability would not be on par with a good XR-E but I would think the deep SMO reflector would still be better than the relatively shallow 52mm dropins when used with the XM-L. Anyone here have any input?
I've done it. Beamshots here. Here are a couple of ceiling beamshots at 60cm from the ceiling. The lights are an XM-L modded HS-802 on high and an Ultrafire 3-mode XM-L dropin on low and high.
HS-802 XM-L modded and 3A driver on left and Ultrafire XM-L 3 mode P60 (The Manafont one with a smooth reflector) in an Ultrafire WF-504B body - it is on low
HS-802 XM-L modded and 3A driver on left and Ultrafire XM-L 3 mode P60 (The Manafont one with a smooth reflector) in an Ultrafire WF-504B body - it is on high. The HS-802 is on high for both. I've not yet stuck it on the lightbox to measure output.
Been Seen/troop are right; with so much horsepower available for so cheap, we can be sloppy and still have a bazooka. I think the XR-E is a fine little emitter and I've got plans for a couple in either an L2 or L2P. I've got an L2m on the way too so, who knows.
Foy
No... So much wrongness...sorry. The XRE is the farthest throwing LED on the market because of surface brightness. Its all about surface brightness. The higher the surface brightness, the higher the throw. The XRE has a 1, or .9 mm^2 die size. It also puts out a given amount of light at a given current. Divide the light output by (Apparent (more on this later)) die size, and you get surface brightness. The XPE has the same underlying die, but it has a different lens, which in XP- packages is a soft silicone one, which acts like a magnifying glass, and increases the visible size of the LED. The XRE has a glass dome, which is held in place by the metal band. The metal band doesn't create a hotspot-it's light reflected out is not from the focal point, and so causes "cree rings". The XPG package is smaller than the XRE......and also thinner. The reduction of spill has to do with the poor design of bezels we use in our p60 hosts: The Malkoffs solve this with a much smaller, shallower reflector, that puts much more of the light put out by the emmiter out the front, than traditional P60 dropins, and also get much superior heatsinking when used with their MD2 hosts, due to a very precise fitting, and the additional contact between front of dropin and front of flashlight. You can't get as much throw from the XML as from the XRE-it just doesn't have the surface brightness.
It is impossible to fully collimate an LED, or any other light source that is not a point source. You can't make light go in a straight line, when you're emmiting it from different places. Its also impossible to have a perfect LED-no silicon is without imperfections.
thanks srfreddy. I'm not totally sure what you said, but I still like the way the beam looks on the XR-E 
Just because the light has a similar emmition pattern (which it doesn't really) doesn't mean it throws the same. IT HAS A SMALLER EMMITION SIZE, SO HIGH SURFACE BRIGHTNESS--> MORE THROW!
Here, for more reading.
Just putting on emphasis. Believe it or not, the guy that wrote that post created the longest throwing LED flashlight ever.
I loaned the city of New York one of my L2Ps so they could take this shot.
IheartNYFoy
LMAO! Two olives and half a martini just hit the screen.... :D :p :bigsmile:
Lovely discussion here! ahha
My thoughts put relatively simply are.
1) Reflector setup is important - In a throw orientated reflector (Most reflectors are of this type, simple true parabolics) you need the emitter to be sitting as close to the focal point of the reflector as best as possible to optimise throw. This applies in all dimensions. Any light source outside of the focal Point is going to be putting light outside the centerline and therefore will not be concentrating the light onto the same spot, therefore making the hotspot wider, instead of brighter.
1a) SO if you place the emitter too high or too low in the reflector, you are reducing throw. (this is how focusing heads work, shifting the led in and out of the focal point along the axis of the reflector. This is the main flaw with most budget reflectors, not getting the emitter height right with emitter swaps. This can be fixed by the manufcturer, or the DIYer.
1b) The same theory applies laterally. . The ideal focal point is just a point size. If you place an emitter to the side, the light will project off the axis of the reflector. So lets now imagine the situation with a larger emitter. The center of the emitter is in the middle of the focal point, and projects light down the centerline axis. The edge of the emitter is not in centerline so it will have its light projected off centerline. How far you go off centerline increases the amount of light that is emitted off centerline. So a small emitter will have less light projected to the sides, while a wide big LED will be projecting light light both left and right farther from centerline. This is visually seen as a larger "hotspot"
2) The brightness of a point in the projected light is dependent on the corresponding point intensity of the light source. What I mean is, the brightness of the center of the hotspot, is dependent on the brightness of the emitter in the middle of the emitter. The XR-E has more light output per unit area of emitting surface (surface intensity) is higher. This means that the light reflected from the led will be brighter. The XM-L has a lower brightness emission per unit area of emitting surface, so the brightness of the hotspot will be lower (less "throw") but as discussed in 1B, the hotspot will be much wider.
3) The main problem for throw is therefore focusing the light onto centerline. As described in 1A and 1B, the goal is to place the light source as close to the focal point as possible. How to achieve this?
3a) Brighter light source - were talking Surface Intensity here, not overall light output. The XR-E is the winner over the XM-L for this.
3b) Use a smaller light source - this will reduce the amount of light projecting off axis. (this is why HIDs throw so well, its just a tiny 1mm line arc of light, not a 3x3mm area of light source.
3c) Use a bigger reflector - so that proportionately the same XM-L will be smaller relative to the reflector, and therefore proportionately not as far from the focal point of the reflector.
The XP and XM packaging had a wider emission profile because it doesn't have that ring. Reflectors make use of light emitted out the side so technically its better suited for reflectors for this reason. The ring blocks the low angle side light and you miss out on using that for throw. My comment is that the packaging of the XR-E isnt well suited for throw, especially the metal ring used to support the lens, it causes absorption of light that is otherwise laterally emitted, and creates reflections off axis, which is why you get cree rings.
There may also be some relevance in the vertical positioning of the emitter which is usually incorrect. but more importantly, Its Fundamentlly the difference in the size of the die and the surface intensity.
Spill light occurs with light emitted out the top of the package, so is light that never reaches the reflector, and you get more of that with XR-E
I would be inclined to have a friend with a lathe do a custom reflector for a popular flashlight tweaked for XM-L emitter. The reflector size of the C8 incidentally is the same as of the MRV apparently. So it would be a wise choice since those two hosts are very popular. Is there someone able to design a perfect reflector so i can give it a try on a lathe? Also how to do the mirror finish? Chrome plating?
If ends up well and costs permits i would try to make a batch for interesents for as cheap as possible. The lathe man will charge me a beer or two and a sixpack for milling a dozen of those i guess. If not he likes knives and i will give him a good one. :)
No moneymaking enterprise here but i tought i would like a few and probably some others too.
Looking for:
- reflector designer with knowledge
- How to mirror finish it (technically)
- Who would want one or a couple for not much of a price which i cannot estabilish yet (mirror finish puzzles me) if i can manage it for a budget friendly amount.
I'm unaware of issues to build one but i'm willing to invest some time at that.
Without someone to design it perfectly this is not going to happen. Trial and error is not an option for such a thing i believe. I'm not qualified or capable enough to design it myself.
vacuum deposited coating is the key here.
I remember a company doing small batches, the oldtimer guys over here all have their ancient headlight reflectors reworked there.
I'll ask around see what I can dig up.
Thanks! I'm prepared for the worse.
Good coatings are also very expensive and hard for a DIY to do properly-even more so for orange peel.
I suspect milling one up to someone specs would be the greatest issue of all.