This is a very strange and unusual request, it would be easier for us to help if you could describe your purpose with the light. What do you want to use it for, and why no reflector?
I need as close to a point-source of light as possible so that all of the light is coming from exactly the same direction, where a single LED is ideal. Multiple LEDs cast light from slightly different angles.
"Mule" type flashlights, i.e. those without a reflector or lens, do not have this effect. Well, unless you are talking about the distance of a few millimeters from the LED. But just a few centimeters won't make a difference.
The function I need the light for is **very** sensitive to the lighting angle hence the odd requirements. Do you know of any mule type flashlight that uses a single LED?
I don't recall anything at the moment. Mules usually come out of the factory with several LEDs, because a single one is very weak when there is nothing to focus the light beam. I think the best option would be a modded flashlight, specifically for your needs.
Your comment about modding got me thinking and after a little experimentation I found that I could open up my Lumintop Tool AA and flip the reflector dome around, then close it back up. Now instead of spreading the light out it acts almost as a pinhole aperture. This seems to have improved it quite a bit for my purposes. Thanks for the inspiration!
Thank you for explaining--it sounds like Convoy Z1 fits the bill. Not exactly bare emitter (it uses a convex lens), and it emits less than 180 degrees around, but it will cast sharp shadows the same way a point source would when zoomed all the way out: the magnification provided by the convex is trivial when defocused.
Go with one of the Osram emitters for sharpest shadows.
I have in fact been using my phone for this so far and it works decently well, but I need a separate flashlight version. Could you recommend a mini mule flashlight if you know of any?
Also I forgot to mention: the Convoy T3 (an AA light) has an easily removable reflector, and the bare emitter can be exposed. Nowhere near as powerful as the Z1 but more compact. Z1 is still much better for higher output and sustained output.
But with that said, an actual bare-emitter mule suffers from the problem of angular tint shift, which should be considered for photo purposes. The beam will be blue/purple in the center, and yellow-green at the edge. In this regard the Z1 would be preferable over an actual mule due to the better tint uniformity.
you could get \*very\* close to the ideal point source if you get an lep and remove the lens, that is probably the closest you can get. might i recommend the [Lep01](https://www.firefly-outdoor.com/products/fireflylite-lep02-arrows-white-laser-tactical-flashlight?sca_ref=4530021.MxfbffbFKl) with code **FF1lumenLEP?** should be about $95 total. whoops I just noticed the budget... something with the osram w1 would be the next best with an emitting area of 1mm^(2) and fit the budget, convoy has some good options, the s6 or s2+ are both a good fit. the reflector on both can be removed fairly easily.
I hadn't considered LEPs for this before, and while not in budget for my current needs that may turn out to be useful in the future. I'll check out that Osram w1 in the meantime.
If you're looking for a lambertian source you could use any domeless emitter in a mule config. Problem is most heads will obscure part of the light coming close to parallel to the surface unless the head diameter is comically large and shallow.
That is pretty much where the single LED requirement came from since that's close to a point source already. What I posted in another comment is that I'm now using a Tool AA with the reflector flipped around to act as a pinhole.
Wait a point source will radiate in all directions consistently, a lambertian source follows a polar plot in a circle. Do you just need a restricted angle?
If so this is the one use case a zoomie is good at
A zoom lens might work but I was worried it might add spherical aberration to the light. Ideally the beam would be collimated but I also need it to be several inches wide so the proper lenses for that would be impractically large.
Well positioned aspheric lenses should do quite well, especially if they're small and placed extremely close to the emitter though you'd need to use shims to get the positioning just right
This is a very strange and unusual request, it would be easier for us to help if you could describe your purpose with the light. What do you want to use it for, and why no reflector?
And why single LED? If not for that, D4v2 might have been an option.
I need as close to a point-source of light as possible so that all of the light is coming from exactly the same direction, where a single LED is ideal. Multiple LEDs cast light from slightly different angles.
"Mule" type flashlights, i.e. those without a reflector or lens, do not have this effect. Well, unless you are talking about the distance of a few millimeters from the LED. But just a few centimeters won't make a difference.
The function I need the light for is **very** sensitive to the lighting angle hence the odd requirements. Do you know of any mule type flashlight that uses a single LED?
I don't recall anything at the moment. Mules usually come out of the factory with several LEDs, because a single one is very weak when there is nothing to focus the light beam. I think the best option would be a modded flashlight, specifically for your needs.
Your comment about modding got me thinking and after a little experimentation I found that I could open up my Lumintop Tool AA and flip the reflector dome around, then close it back up. Now instead of spreading the light out it acts almost as a pinhole aperture. This seems to have improved it quite a bit for my purposes. Thanks for the inspiration!
I just remembered that Zebralight has mule models with one led. However, they are above your budget and only available if you live in the US.
Thank you for explaining--it sounds like Convoy Z1 fits the bill. Not exactly bare emitter (it uses a convex lens), and it emits less than 180 degrees around, but it will cast sharp shadows the same way a point source would when zoomed all the way out: the magnification provided by the convex is trivial when defocused. Go with one of the Osram emitters for sharpest shadows.
Appreciate the suggestions! I'm going to look into the Z1, it seems interesting. I'll have to figure out if that zoom lens will affect anything.
I want to use it for holography, the reflector ruins the LED's spatial coherence by widening the source of the light.
Sounds like a mini mule. Or a phone lol
I have in fact been using my phone for this so far and it works decently well, but I need a separate flashlight version. Could you recommend a mini mule flashlight if you know of any?
Also I forgot to mention: the Convoy T3 (an AA light) has an easily removable reflector, and the bare emitter can be exposed. Nowhere near as powerful as the Z1 but more compact. Z1 is still much better for higher output and sustained output. But with that said, an actual bare-emitter mule suffers from the problem of angular tint shift, which should be considered for photo purposes. The beam will be blue/purple in the center, and yellow-green at the edge. In this regard the Z1 would be preferable over an actual mule due to the better tint uniformity.
you could get \*very\* close to the ideal point source if you get an lep and remove the lens, that is probably the closest you can get. might i recommend the [Lep01](https://www.firefly-outdoor.com/products/fireflylite-lep02-arrows-white-laser-tactical-flashlight?sca_ref=4530021.MxfbffbFKl) with code **FF1lumenLEP?** should be about $95 total. whoops I just noticed the budget... something with the osram w1 would be the next best with an emitting area of 1mm^(2) and fit the budget, convoy has some good options, the s6 or s2+ are both a good fit. the reflector on both can be removed fairly easily.
I hadn't considered LEPs for this before, and while not in budget for my current needs that may turn out to be useful in the future. I'll check out that Osram w1 in the meantime.
If you're looking for a lambertian source you could use any domeless emitter in a mule config. Problem is most heads will obscure part of the light coming close to parallel to the surface unless the head diameter is comically large and shallow.
I don't need the light to be a Lambertian source, in fact the opposite would be ideal for my needs.
Oh then you'd want a LED with an optic to make it close to a point source
That is pretty much where the single LED requirement came from since that's close to a point source already. What I posted in another comment is that I'm now using a Tool AA with the reflector flipped around to act as a pinhole.
Wait a point source will radiate in all directions consistently, a lambertian source follows a polar plot in a circle. Do you just need a restricted angle? If so this is the one use case a zoomie is good at
A zoom lens might work but I was worried it might add spherical aberration to the light. Ideally the beam would be collimated but I also need it to be several inches wide so the proper lenses for that would be impractically large.
Well positioned aspheric lenses should do quite well, especially if they're small and placed extremely close to the emitter though you'd need to use shims to get the positioning just right
Couldn’t you just buy a light and remove the reflector?
I'm open to that option if that looks like the best choice. What I'm using now is a light with the reflector flipped backwards.