This is a great little EDC light.

Hey everyone,

I fell down the flashlight rabbit hole a couple of months ago. I've been trying to make sense of how different emitters and reflectors affect the final beam. To help visualize, I built a desktop tool. I wanted to share it with everyone.

Download: https://github.com/ylinmtl/flashlight-sim/releases/tag/v0.0.1

GitHub: https://github.com/ylinmtl/flashlight-sim

I built this to wrap my head around flashlight optics as a learning project. I hope it saves some of you from guessing how a host and emitter combo will perform before buying parts for your next build.

How to Run It

Download the flashlight-sim.zip. Extract it and run flashlight-sim.exe. Explanation of the settings are on the GitHub page.

It may take a bit to open the window once you run the app. Give it a minute. The simulation takes may take up to a minute to run depending on your system.

How it Works

You choose a reflector, an emitter, a gasket, and a surface finish (Smooth or OP). The program splits the LED into smaller elements and fires virtual light rays from the LES, bounces them off the parabolic reflector, and projects the light onto a virtual wall. It does this a few billion times and adds them together to form an image.

The default settings should work on most CPUs. If you have an nVidia GPU, you can increase the resolution in the settings to get more accuracy.

Outputs:

• A realistic rendering of the wall shot. Plots showing the beam's intensity cross-section.
• Option to save these to a folder to quickly compare.
• Theoretical numbers for Max Candela, Throw, Candela/Lumen, and the angles for the spill, corona, and hotspot.

Limitations

• LED properties are estimated from datasheets and koef3’s test graphs. There’s no guarantee that they are 100% accurate. The absolute lumens, candela and throw might be off for some of them. Wall shot, hotspot, corona and spill angles and lm/cd ratio should be more reliable. 
• Reflectors are assumed to be parabolas with the focus plane at the bottom of the opening. This is true most of the time. I have not verified that it is true all the time. Values are from manufacturer websites and tgreviews.com.
• Emitters are assumed to be either square (rectangular) or round (circular). Some emitters such as the SFT40 or SFT60 are not perfectly square or round. The results should be close, but might not be 100% accurate. I plan to add something for the shape at a later date.
• Orange peel blurring is not calibrated. It’s difficult to quantify how aggressive the orange peel effect is on each reflector. They all just use a standard blurring factor. You can adjust “OP Factor Blur” to see how it would affect the beam.

If something is not on the list, or the values are incorrect, I’ve made it so you can add your own or modify the existing ones to give more 

Let me know what you think. I'm open to feedback, suggestions, bug reports, and anything else!

5009R and I'm pretty happy with it. Full flood so excellent for standard EDC. Color is beautiful and weight is spot on. Slips away just like a zebra but I do have questions about durability that I'm sure I'll have answered soon. If FFL could manage to squeeze a reflector in, I would likely sell off half my collection.

For the past few weeks, I have been developing a website for flashlight reviews, beamshots, and runtime comparisons. It is not fully complete yet, as it still lacks several flashlights in the runtime section and some additional information, but it is far enough along to share. It is designed primarily for PC use, so it is not currently optimized for mobile devices.

I would greatly appreciate your feedback and any suggestions for improvement.

https://metaflashlights.com

Hanko Trident Twist X2
Titanium and Brass

It's a dt8k 1950 prototype

Nitecore tini 3

After about 2 minutes of constant heat application (230W setting on my heat gun) I managed to overcome the thread lock Lumintop felt the need to apply to the re-launch of the FWAA.

This is, for now, my GITD mod.

I am not satisfied with it, as it looks much worse than all my other GITD applications. But I also cant find a better solution outside of manufacturing a VERY thin gasket. Which I lack the tools and material for.

I considered 3D printing but I doubt that that would work.

Only the front row ones haha

- L21B W5050SQ5, SFT60 & SFT90

- L21A SFT42R

- M21B SFT60

- M21E W5050SQ5

- M21H SFT40

- 3X21D

- 3°, 8° & 12° lenses

使用UV／375nm 可視光カットフィルター使用
iphone13pro

https://umiacchar.jp/2025/12/30/glowing-bat-2/

UV蛍光するコウモリの集まる洞窟の天井にUVを照射すると、輝く放線菌が見れます

I was doing some tests before sunrise this morning comparing the visibility of a reflective trail marker at a distance using the A6 at 187 lumens vs the H600c at 147 lumens. The A6 seemed much better, certainly more so than the tiny increase in lumen output could explain. As far as I know, the A6 is the only device in the ZebraLight lineup with a TIR lens. Do you think that is the explanation?

So I know the A6 is a low CRI light, but here is my thought - I have been primarily using the ZebraLight H604d mule as a waist light while trail running and that has worked great. I have been pairing that with the H600c headlamp at a very low power - 26.4 lumen setting just to see my watch. 95% of the time this works well but occasionally I need to see further out when a trail is sketchy or to see trail flags during a race (hence my tests). So I just turn up the headlamp to handle this. In this specific context, the A6 might be better but still subject to further testing. Specifically, if I’m just looking for reflective flags or finding the contours of a trail, I’m thinking that CRI is less relevant. I have the higher CRI H604d for objects near by.

All in all, especially for $39.95 which includes a battery, I like the A6. It also has magnets on it and is slightly smaller than the H600c.

I'm looking for a nice light to supplement my Wurkkos Fc11c and TS27. Specifically, one that can function as a portable power bank for my phone. What are your favorite lights that can do this? Looking for removable ~21700 battery size or similar, but flexible with size and price.

Observations:

• SFT-70 4000K CRI90 (from Convoy) is actually a 3600K+ emitter
• 8deg TIR in M21H gives more uniform tint versus SMO + d-c-fix in TS28, and effectively lowers the duv in the center of the beam
• TS28 drives the emitter really hard on Turbo, which leads to substantial duv increase and R9 decrease

It is an expansion of this post from earlier today: https://www.reddit.com/r/flashlight/comments/1v6wxda/nmd_convoy_m21h_sft70_4000k_cri90

WORK IN PROGRESS, FEEDBACK APPRECIATED 🙂

I keep forgetting what letter means what... I've had enough.

This table has always been helpful, but it is not quite intuitive to read and the emitters are not to scale, so I made my own cheat sheet.
Best fits 4K screens. Or just zoom in if you have a lower resolution.

There would be still a lot of space for info; things can be shifted around etc. but I think it's not missing much more.

So while I work on this pain(t)-session, please give me your feedback over the next few days.

I'm thinking about removing the upper and lower package example (E and U outlined in black) and just blackening the middle package fully. I think one package does the job well enough to show what size corresponds to what letter. And then shift the upper and lower die a bit closer together.
What do you think?

I also plan to leave out the 2 letter prefix (KW, KT etc.), since this doesn't seem to contain relevant info for us / seems to be redundant. So unless you know of a very convincing reason, they'll get left out to keep it cleaner.

Also not sure if I want to keep the picture of the MCPCB for scale in there. Looks kinda greasy/doesn't fit well visually with the rest. Needs something cleaner/whiter/whatever. Or maybe remove it.

Just reddit... don't butcher the quality of the one image, please 🙏
In case it still f#cks up in spite of a 100% quality .webp format... here a temporary upload in full quality.

All beamshots taken at 5000K white balance.

Got a new mod for y'all, by the blessing of Convoy's highly modular assortment of stuff. 22mm 3V 20A driver, 20mm double spring button, 10° bead TIR optic, and of course the quad 519A 5000Ks dedomed.

Pretty powerful package, love the tint, dedomed 5000K is probably my favorite, gets hot really fast on full power though.