Not sure if this mirror would help, maybe the focal point is too far away…
Telescope mirrors have focals points several times their diameter away, sometimes even several meters.
We need something with F 1/4 or around there…
I found this, which is pretty much exactly what we need, but it’s not available on this site anymore.
Also, it was a lot of 7, but we only need one or two.
https://www.aliexpress.com/store/product/140mm-diameter-glass-reflector-with-coating-for-operating-light-lamp-with-hole-28mm-diameter/703379_32289567832.html
$30 a piece is a great price for a glass reflector, and from what I can tell the focal point would be slightly in front of it, so not full 180 degrees but still very close (closer than the cosmetic mirrors I posted earlier)
If someone has free time, search around the internet and see if you can find a place that sells these individually or in a lot smaller than 7.
The search term I used is “140mm glass reflector”
Aargh….
How frustrating…
Good lead though, looking for operating lamp / dental lamp reflector now, but for now only this pops up:
Look, how nice it is faceted… :weary:
I thought about those a while ago but decided nah because of the way it is made in strips, it will give a really bad spot at a far distance…
Needs to be a smooth parabola, so glass or metal 
This:
Djozz, how about we buy 10 of them together…?
Either way, enquiry sent.
[EDIT] Mêh, probably too deep anyway…
wow that is a monster!
$ 43.49 + $ 8.13 shipping = $ 51.62 :sunglasses:
Ok, so the mirror I tested with was 10x, and the vocal length was slightly over 1x the diameter, so a bit over F1, captures about 60 degrees angle.
It does make a die projection smaller than the 78mm aspheric lenses I have around, although probably not smaller than my 100mm lenses.
Too bad it doesn’t focus well, otherwise I would be able to measure the lux.
I think with a 15 or 20x mirror you should be able to get 90 degrees or even more, but nowhere near 150+.
This will be good for throw though, just not so much light efficiency.
I’m still planning to buy a few of these makeup mirrors in january to do more tests, hopefully they will be much better focusing than the one I have.
I did a ray trace of the glass mirror I mentioned before: http://www.traderscity.com/board/products-1/offers-to-sell-and-export-1/o-t-light-shadowless-glass-reflector-mirror-160mm-140mm-156711/
It will capture almost exactly 180 degrees, ± around 30 since the depth is not listed accurately.
Still trying to find a place that sells it individually or in a small lot.
Also about that head “lamp” you found… 
the reflector is too big at 18cm but since the focal point is like half way deep you could probably cut out about half of it and end up with something about 100mm which captures the 180 degrees from the LED. $50 for something you need to cut is a bit too much imo, but if you want to try it you can still test it without cutting, but like 75% of the reflector will be unused.
The complete headlamp including helmet is 52 bucks shipped !!
You only need a battery.
The reflector alone can be bought for about 18 bucks plus 8 bucks shipping.
Yes, then you have to get rid of the outer perimeter to make it useful for a recoil setup.
But then i honestly thought: Why bother and instead just get that whole damn 150 Watts HID headlamp? 
Reflector for 18 bucks is good, get it and test it 
IMO $50 for a cheap headlamp which won’t even be usable after you take the reflector out isn’t worth it, but if you take the parts and use the ballast and lamp for stuff I guess it’s not a waste.
How about keeping it as is, and blasting the heck out of every other portable light?
Seriously though, if i got only the reflector, i would have to carefully cut a lot of it off and still have a hole in the middle, and it wouldn’t even be the size i wanted.
Maybe next month though.
I’ve been spending money like crazy since i’m back here in flashlight land.
[edit] Also that store / site doesn’t do Paypal so i would have to think of something to use a credit card which i don’t have myself.
The hole in the middle isn’t that bad, if you remember the graph there is very little light actually coming straight forward.
Also, personally I would be using a copper star which would block out that tiny part anyway. Pretty much all searchlights like the maxabeam have a hole in the middle and it makes little difference to the overall throw.
ah, yes, but per square inch reflector surface it’s still the best bit, but indeed, just a few percent of the lot i guess…
Hmmm…
My thinking is that a 3535 (or 5050 for that matter) LED is actually just perfect for a recoil setup (without a hole), i don’t want to ruin that idea with a relatively big MCPCB.
Otherwise i might as well get some HID setup with readily available parts.
For the love of the concept, I will keep pursueing the ultimate recoil thrower, but a simple experiment with a 16 dollar fresnel lens (200mm diameter, F=200mm) shows numbers that will be hard to get in the recoil set-up, with an easily mounted led.
Set-up with fresnel lens and flashlight (optic removed, XP-G2 S4 2B dedomed @ 4A), note my professional lab-environment :sunglasses: :
The spot at 7.00 meters from lens (flashlight at low setting for the picture):
This measures 3.64 Mcd. If I have time I will make a box spotlight with this set-up. I made one before with a much larger lens (350mm diameter, ~150mm focal length, 5.4Mcd), but this will be considerably smaller without loosing much throw.
Btw, with this 82mm diameter ‘20x’ beauty mirror ($8), I measured 320kcd, with the flashlight and clamp blocking some of the reflected light, so perhaps 400kcd if the led was mounted well. This is the same ballpark as the 60mm lens UF1405, so per lens surface area it is worse.
But it is the best result sofar (the cigarette lighter mirror has a bit larger diameter, plus I used no bulky clamp but a wire to hold the flashlight so less light was blocked in that experiment), and with a cheap and easy to keep clean glass mirror.
Seeing the large spot artefacts I asssume that an optical quality mirror will throw perhaps 50% better. It still looks like that the throw/lens surface area is quite constant, no matter if the optic is reflector, aspheric lens or recoil mirror.
I’m not gonna do anything recoil unless i can source a decent aluminium plated reflector that will reflect 120° or more from the LED.
Otherwise there is just no point in pursuing it any further.
djozz is right, with the same focal distance and diameter, a recoil reflector should perform exactly the same as a lens, plus or minus the light efficiency of each.
A good reflective coating is 90+ reflectance, while a good lens is usually 99+ reflectance, but a good quality lens of large size is usually extremely expensive.
Longer focal distance will make the spot smaller, but more degrees of light collection will add more lumens.
The way to get more lumens + small spot at the same time (aka higher intensity) is by having a longer focal length while keeping many degrees of light collection at the same time.
This means using a larger diameter, whether it is a lens or a reflector.
The benefit of using a reflector instead of a lens in a case like this is that getting large high quality lenses is harder and more expensive than getting large high quality reflectors.
Djozz, do you have any pics of the spot from the mirror you used? I’m curious to see how distorted it is.
I might buy myself this one to try out for fun, has some better reviews than the one you got: https://www.amazon.com/Harry-Koenig-Co-Magnification-Suction/dp/B0044FEH1U/ref=pd_sim_194_4?\_encoding=UTF8&pd_rd_i=B0044FEH1U&pd_rd_r=M66MNXRP7V6MXW48EKKS&pd_rd_w=bu3YA&pd_rd_wg=9hloT&psc=1&refRID=M66MNXRP7V6MXW48EKKS
I bought this, 5.5”, one of the highest reviews mirrors:
Still can’t focus perfectly, there are multiple die reflections and it’s impossible to get them all in the same place.
Seems like even these makeup grade mirrors can’t focus the light well enough.
I think the only option is a professional grade electroformed reflector, no cheap consumer options will do the job.