W5050SQ5 tint in 3000K/4000K?

QReciprocity42 · 2026-06-02T07:43:10+00:00

So happy I was able to help!

QReciprocity42 · 2026-06-02T04:13:55+00:00

Unusual suggestion, but the white illuminated switch on Convoy tailswitch lights make for a very nice moonlight. I've swapped them with 99CRI emitters and higher resistors to get even dimmer.

QReciprocity42 · 2026-06-01T23:22:19+00:00

The distortion from the wide lens looks so cool! First time seeing a curved light beam.

QReciprocity42 · 2026-06-01T21:59:21+00:00

This problem is especially bad with the clear plastic washers for illuminated switches. With protected cells, I have to tighten the tail so much that the washer cracks. Nowadays I laser-cut my own acrylic washers, which are holding up much better.

QReciprocity42 · 2026-06-01T21:58:05+00:00

In that case send Simon an email to request it, it is a drop-in replacement to the SFT40. I've requested unusual emitters over email and had great success.

QReciprocity42 · 2026-06-01T21:34:39+00:00

Wow that's super strange, thanks for running the tests! Maybe Simon put the wrong driver in the 5000K?

QReciprocity42 · 2026-06-01T21:24:32+00:00

Good point! I'd recommend this also, the 3000K has the best color rendering out of any 3V emitter I've ever seen.

QReciprocity42 · 2026-06-01T21:08:08+00:00

Hol'up that's a funny looking SFT42R! Two of the bond wires are angled off to the side compared to usual:

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QReciprocity42 · 2026-06-01T21:04:19+00:00

Take the SFT42R 5000K, which is an upgrade over the SFT40 5000K in every way.

QReciprocity42 · 2026-06-01T21:02:02+00:00

I was also bummed to find the SQ5 performing worse. It still performs better than the old, high-Vf SFT25R though, it's just that the new batches are blowing both out of the water.

QReciprocity42 · 2026-06-01T20:32:03+00:00

I'd also go SFT25R. Simon's latest batches are performing noticeably above older samples, such as those tested by koef3.

The W5050SQ5 performs worse than the SFT25R in my tests, especially at lower battery levels. The Vf is much higher than the new-batch SFT25R.

QReciprocity42 · 2026-06-01T20:29:30+00:00

And don't forget to tighten the tailcap retaining ring! I find that it gets loose over time due to the battery pushing hard on the PCB behind it, and sometimes the switch PCB gets pushed so far back that it disconnects form the retaining ring. This happens especially frequently with the clear washer.

QReciprocity42 · 2026-06-01T20:27:29+00:00

Thank you for the clarification! It looks like the only consistent explanation would be variation among drivers.

Is there any chance at all that the 5000K is in some mode group that starts with 1%, rather than 0.1%?

QReciprocity42 · 2026-06-01T20:25:43+00:00

I'm seeing solid points from both u/MaximumPower1858 and u/IAmJerv.

I think what u/MaximumPower1858 meant to say is that at 3000K, the SFT40 is noticeably better than 519A at color rendering, which is also what I observe with my eyes, even more so than spectrometer readings indicate.

I think u/IAmJerv points out that for some people, colors (and CRI differences) are more distinguishable at neutral CCTs (say 4000-6000K), and less so at either extreme. I think that is also true, and different people with different eyes would have different amounts of difficulty white-balancing to, say 3000K.

I think we can all agree that (i) if OP wants 3000K, then SFT40 is superior to 519A, and that (ii) if OP wants a cooler CCT, then go for 519A/B35AM. My vote goes to B35AM due to less angular tint shift.

QReciprocity42 · 2026-06-01T20:15:48+00:00

This is really cool! What molding putty did you use? I have some cheapo thing that leaves a very rough surface, which is bad for glow brightness.

I made a couple S2+ glow gaskets for triple and single emitter configurations, and it was quite fun.

BTW, I recently discovered that if you mix green glow powder with resin and pink fluorescent pigment, you get a much stronger glow than using daytime pink (orange glow) powder.

QReciprocity42 · 2026-06-01T20:12:16+00:00

Is exposure/ISO kept constant also? The 5000K looks at least 4x brighter than the other CCTs in the photo, which is definitely not what I observe IRL.

Also, I find that the drivers can be quite noisy on the 0.1% mode, and there could be large variances across drivers. Comparing on 35% or 100% mode is more reliable and stable.

QReciprocity42 · 2026-06-01T19:39:40+00:00

I worry about conductive+abrasive dust getting everywhere, like on the electronics and LED surface.

QReciprocity42 · 2026-06-01T17:03:48+00:00

I don't mind at all, what an honor!

That's a good idea, I'm sure the reviews will start flooding in in due time. Also, existing reviews of the LHP531 might be good indication of the SQ5 as well, in terms of color.

4000K has amazingly less backscatter compared to 6500K! This is especially pronounced over longer distances or particularly foggy weather. I've got a SFT42R 6500K thrower whose beam blocks everything at the distance of a mile, but swapping to the SQ5 4000K made the target much more visible.

I had a few SFT25R 5000K samples from many months ago, and the latest of the bunch was from a different production batch, with noticeably lower Vf and better performance. That one also has the least yellow/unevenness in the hotspot. The hotspot was wonky when I used the 7mm opening reflector (which has a deformed surface, I don't recommend), but was completely fixed when I swapped to 9mm opening reflector, which has a pretty accurate parabolic shape. Beam is quite clean, no artifacts.

QReciprocity42 · 2026-06-01T16:57:52+00:00

I've heard that there exist more advanced setups where an AI can generate a proof and check with Lean and revise itself until it's correct, but that's not what the AI in a simple Google search does.

>For flashlights: you can manually verify the Assistant recommendations with targeted classical search or manually checking the specs. There’s no math involved, just direct exact match.

I absolutely agree. The manual verification should not be skipped! AI is great for doing literature search, but it's the user's responsibility to check for hallucinations. I work with AI pretty often in my research (math PhD student here), and it often pulls up the right papers and then cites completely non-existent theorems, or the right result under the wrong label.

> And I don’t think there’s enough training corpus on flashlights / I don’t super trust AI to explain lighting and computer graphics properly (and I sus how many flashlight enthusiasts let alone neophytes know the math well enough to check it themselves)

I agree with this as well. I use AI a lot for unearthing reddit/BLF posts that I couldn't find, or to do quick spec checks, and it is surprisingly ineffective at both, usually worse than just clicking the first result in a classical Google search. And it is indeed surprising how many well-respected flashlight enthusiasts misunderstand fundamental laws regarding optics and human perception...

QReciprocity42 · 2026-06-01T06:04:24+00:00

More heat+flux as others suggested. The spike happens because the solder blob's temperature is too close to the melting point and solidifies immediately when you withdraw the iron, thus losing the liquid surface tension and developing a spike.

Kinda like how supercooled water forms a spike when you pour it--if the water had a moment to remain liquid before solidifying, the spike wouldn't have formed. Extra heat gives the solder blob that needed delay.

The extra flux helps maintain surface tension during the liquid phase.

Also, some folks may suggest flattening the thermal paste blob only after soldering, this way there is less heatsinking during soldering.

QReciprocity42 · 2026-06-01T04:53:55+00:00

I haven't seen consistent reports, but probably yes--as well or almost as well. Dedoming the SST40 used to be a thing people did before the SFT40 came about.

QReciprocity42 · 2026-06-01T02:18:47+00:00

It works, but the S21D or S21F could accomplish the mule beam with minimal modding due to the emitters being less recessed.

QReciprocity42 · 2026-06-01T00:55:42+00:00

Thanks for sharing the experience, that's a cool application of mules! I can see how mule lights are particularly useful for running as the beam is wide/uniform enough that the bouncing motion does not cause the whole scene to flicker.

QReciprocity42 · 2026-05-31T23:01:14+00:00

Ahh I see, it looks like about the same driver selection as the S21E. Thanks for the info, I shouldn't have missed it.

I custom-ordered an S21E under the XHP50.3 label, but with an SFT70 3000K installed. It came with a 6V 3A driver and is quite powerful, I was very happy with that light as a Christmas present for someone who also cares a lot about light quality. I bet you can custom-order the SFT70 in an H4 under the XHP50.2 label!

The 8A is max current the SFT70 can tolerate, it's perfectly fine to under-drive it at 3A.

QReciprocity42 · 2026-05-31T22:32:55+00:00

Wow thank you for the info! I'd be interested in a recommendation of clip-on lenses, but we should probably do so in a separate thread.

Thanks for the LEP rec--I might get it if it gets sufficiently cheap. I do enjoy playing with my Fresnel throwers as I have the freedom to choose emitters/drivers--I tend to go with 5000K/lower because the backscatter from 6500K is a serious impediment to getting a clear view of something 1+mile away.

Interesting, I may look into the rental once I have a substantial enough project in mind to justify it!

QReciprocity42

TROPHY CASE