[REVIEW] Acebeam W10. 1KM of throw, in your front pocket. 21700/18650, USB-C charging.

It’s actually not as hard as it seems if you have a high contrast, because ambient light causes the collar to project an inverted image.
For example, a tiny black dot on a piece of paper.
The collar will project a shadow identical to the dot.
You know it is in perfect z-height focus when the shadow is as sharp as the original dot, and you know it’s in the right x/y position when the shadow is on top of the original dot.

We need more practical use beam shots.

But at only 185 lumens and no regulation, this is REALLY hard to justify!

I see a lot of doubts about aspherics giving good throw, too be fare this and the weltool Lep fire the laser into the phosphor and intoa reflector that then sends it through the aspheric.

For a long long time I’ve been asking for a double aspheric lens flashlight to do what this is doing, a ridiculously tight beam in a narrow package. This does it even smaller.

Double aspheric lens had been the king of throw with led’s from 8 or 9 years ago. The setup was the a little bigger than an arm. It was a pencil beam with no spill.

I believe illum (illumination supply) had a code Spooky for Halloween for a discount.

Is this a double aspheric flashlight? I thought the optics is just a single lens projecting the laser-excited die ?

No it’s not, this achieves the same effect with a lot less length.
Mostly due to the laser diode

Agreed.

It’s not a double aspheric. It’s a laser that points backwards onto a phosphor plate. That phosphor emits light which goes out the single aspheric lens.

The tight beam comes from the very high intensity allowed by the LEP, which is about twice that of the most intense available LEDs.

There is no “reflector” in the weltool.
Unless you’re talking about the 45 degree mirror in the center of the lens which has literally nothing to do with the beam or throw.

Is a double aspheric a flashlight that first uses an internal lens to produce a virtual reduced image of the light source inside the flashlight head which is then projected into the world by a second front lens? I have never seen such a flashlight but it will take up quite some extra length (like several cm).

A double aspheric cannot improve throw compared to a single aspheric of the same diameter.

To date I’ve never scene one factory made, just hobbiest made.
Their was a tutorial someone did on YouTube called LightCannon. Had 5 or 6 parts to the video. But that wasn’t the first one ever made. That one looks like it’s almost 3 feet long.
The length between lenses probably varies based on the led

I believe it can if it is a two-stage system with an intermediate image. The first (very short focus) lens creates a reduced size intermediate image that is projected by the front lens of the light.

Edit: on second thoughts it will not work because the reduction step by the first lens requires a limited incoming beam angle, so the secondary virtual light source (the intermediate image) will be reduced in size but the luminance will be the same. netto result: lots of light wasted and a smaller hotspot but without throw increase.

This is the lastest one that was made

That is Endermann’s Optofire, it does not use a double aspheric lens, just a single aspheric lens for projecting the hotspot. It does include a Wavien collar but that is a completely different piece of optic, has nothing to do with the imaging of the led die.

Depends on F#.

It does the same principle as a double aspheric, Two focusing points.

I don’t think the original thread that someone did on double aspheric lenses survived in CandlePowerForums.

Hi, I made the Lightcanon and the Optofire :slight_smile:
They don’t use double aspheric, they use a single aspheric and a wavien collar.
Only one focusing point.
The collar reflects unused light back at the LED, so the same focal point as before.

Something like this uses a double aspheric: Sold/Expired - Mjölnir - Custom made Searchlight with Lens-System | Candle Power Flashlight Forum
The double aspheric system does not increase lux, it increases lumens.

The wavier collar reflecting the unused light back at the led until it makes it out in a specific direction, changes the beam pattern and refocuses the light, atleast that’s my understanding.

Double aspheric increases lumens that hit a specific spot so how does that not increase Lux.

With a wavien collar the beam pattern does not change, nor does it refocus light.
Since it is all bounced back to the LED, the light that is bounced back increases the led intensity by bouncing off of the LED again.
Both before and after it is coming from the area of the LED, so the beam just becomes brighter and nothing else changes.

With a double aspheric you do get more lumens but they are not “in a specific spot”, they actually are spread out more.
If you compare a single aspheric to a double aspheric, the double aspheric will project more lumens but the projected spot of light is bigger.
It is a linear relationship, more lumens -> more area = same intensity.
Since lenses aren’t perfect having the second aspheric will slightly reduce the light transmission and total lux.

Reflecting the light back at the led until it makes it out the hole, does change the beam though, your just running a reflector backwards creating a tighter hotspot.
Any kind of reflector will help throw light but they all change the beam in some way.
I don’t disagree that two lenses means light loss for each lense that the light passes through.

No, no tighter hotspot, exactly the same size. Brighter but not tighter. The wavien collar is not part of the optical system that projects light from the led to the hotspot.