The LEP Flashlights discussion thread - discuss LEPs here

Thanks djozz. I wasn’t aware that these lenses are poor quality, I thought they focused reasonably well. I’ve got half a mind to put an osram led in it just for comparison. Lep seems expensive for the meagre gains. At least that’s my first impression :disguised_face:

Thank you for sharing more info about your project, nice to see more. I have one question I've searched and searched for the answer to and so far, unable to find it; why is the light from the phosphor able to be collimated into such a low divergence beam, compared to an LED?

It is all about the size of the light source. The hotspot of a lens, or a reflector is in fact a projected image of the light source. Make the source smaller, then with the same lens you get a smaller projection (=lower divergence).
The LEP flashlights are so good throwers because a focused laser onto a phosfor creates a light source that is 10 times smaller than the smallest led while having the same light output.

Early in my learning about laser diodes someone told me the reason the divergence is so low is due to having a very small point source, at least, smaller than incandescent lamps, so this agrees with that information, thank you. This also indicates the beam from the laser diode is focused into a very small spot upon the phosphor, but some of those phosphor targets are fairly large, which surprises me. I guess only a very small portion of the target is actually focused upon by the laser diode.

Interesting. So a tiny little defocusing lens could spread the laser light onto a much larger phosphor area, which would presumably help with heat and would create a floodier (or really, less insanely pencil-focused) beam with fewer speckle artifacts. There must be some reason no one is doing this.

You mean like a remote phosphor …?

SLD are working on one laser source with fibre optic to remote phosphor for lighting and communication.

I found a shop with some W30s so I got another 9 of them and 16 remote pressure switches. All up I have aquired a total of 19.
According to acebeams numbers the quad is 2000 lumens and throws 4800m so 16 should give me 8000 lumens and 9600m. They will each have own battery and the pressure switch cables will plug into a switch. The switch has to be 40 amp.
I still have to pick new ones up but I have half of them.

@grin.. wow, that's amazing.

I wonder if they would hit that far, because the beams would be quite far away from eachother.

Anyway.. thinking about doing some beamshots comparisons...

Please let me know what you guys think:

Let me know in the comments of this video:

The quad when aligned forms a diamond spot. Not exactly sure how to make the bracket yet have some ideas.

Here is another module on that express site it is 800lm so I ordered one.
“LEP 800LM” 淘宝网 - 淘!我喜欢

^ I saw that one but thought it’d be pretty hard to stuff in a regular size torch… might work for a grin sized light though :wink:

Also saw these - https://m.aliexpress.com/i/32896735068.html?gatewayAdapt=Pc2Msite

Chibim, I’m curious do the available lep’s show a hot spot in the beam ?

That LEP module looks a little unusual to me. At least from what I've seen in flashlights.

@pinkpanda3310: what do you mean? Do you mean in the middle of the beam? The beam is already very concentrated

I tried to get a beam shot of the 1504 conversion I did but I can’t get it to show clearly.

What I can see, the projected image, is clearly the phosphor disc with a hotspot where the laser is focused. Are lep’s normally like this?

The laser adapter was before the modules available now. Interesting how different types are becoming available.
I would be interested in beam shots of the owl eyes 2. Tonight I will get beam shots of the w30 quad.
PP there shouldn’t be any spill just the hot spot.

There’s no spill per se, rather a hotspot within the phosphor. The pic above is looking through a welding mask directly at the phosphor. You can see the hotspot where the laser is focused.

FYI:

I bought some of these phosphor targets deposited upon a sapphire wafer and was disappointed they were not mounted on a heat sink plate, as shown in the product photo #1., the item size shown is the full diameter of the whole piece, not the phosphor.

Transmissive White Phosphor Plate,Cct And Size Customizable - Buy Phosphor Plate,Transmissive,Customizable Product on Alibaba.com

Chinese sellers often disappoint.

I think that as the laser increases in power more of the phosphor is excited. Is there a limited amount of light that can be generated in the phosphor? Is there a lens on top of the phosphor?
W30 has a small lens between the mirror and phosphor. The laser and lens are fixed and can’t move.


You can see the rebate where is sits.

I would sure like to know what the beam does on the output of the lens before it hits the mirror, whether it is collimated to infinity focus, or is focused down to a point :)

Can you tell me what the approximate diameter is of the phosphor itself?

The small lens is just a Pre-Collimator to generate the Lumen
and make a bigger spot.

You can use it, or not.

At my Lep Modul,

there is no lens.

Regards Xandre

You use 2 lens if you can’t get a lens with the exact focal length. It doesn’t matter where the secondary is so long as it catches all the light and directs it to the primary.
This is how it works both are in focus and collect all the light.
Short focal length makes the beam wider


Long focal length narrows the beam

By the way nice pictures :+1:

Regards Xandre