You didn’t explain anything, you keep repeating “give me deep reflector because more throw”. You keep repeating that despite being proven wrong. S2/S7 reflector WILL NOT throw better than stock S21E’s reflector because the latter is wider
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I am in full support with this.
I like 3V LEDs and if those LEDs are all as goot as the LMP LEDs or NV1010 CRI90, then there is no reason for me to not want this.
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SQ5 fails to utilize its full potential with a half empty battery.
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To make unsubstantiated claims without justification is not the same as explaining–to explain something is to justify it. If you did have a physics PhD as you claim to, you would have been well aware of this distinction.
A pathetic cover for your inability to earn credibility through logical reasoning.
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Well we don’t have a true parabolic shape because we’re lopping off the bottom by making a hole in it. A larger hole means we’re going to get less throw because we’re taking away more reflective wall.
When lumintop changed the reflector on the fw1a to a larger hole to accommodate a 5050 along with a tall non-reflective gasket the flashlight lost approximately 30% of its throw even when used with a small 3535.
The reflector used to have a series of reflective angled sections at the bottom that basically provided a gasket -less system.
So the smaller the hole is and the more of the full parabolic shape we can keep all the way down to the LED at the proper height the more throw we can get out of any specific reflector height.
I contend that there is room to get more throw out of the s21e within the same space by making that hole smaller and using a gasket that is not as thick.
There is some wasted space down there.
Edit. This comment is thrown out for all not in relation to any one specific comment above.
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I have only one light using a 3V driver, all my other lights use a 6V driver now. I would miss the boost drivers.
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I’ll still respond because the comment is relevant to an ongoing sub-discussion.
I agree with this fully, and this is indeed the reason why deeper reflectors throw more. It would be useful to quantify this relationship, which is what I attempted in the past few posts. The conclusion I drew is that while this increase in throw is present, it is too small to be meaningful, especially compared to the throw you can gain from expanding the diameter instead of depth.
I did a quick plot of how intensity grows (i) with depth for a fixed diameter, and (ii) with diameter for a fixed depth. It is clear that both plots are increasing; my conclusion is that the intensity vs diameter plot grows much faster, and for this reason, diameter is a more effective contributor to intensity.
I agree, and I miss more 6v leds. Simon should supply LMP leds in 6v configuration.
3v is good for buck driver with 2 cells in series, but I’m afraid to use this way.
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It would be nice if Simon could make 6V-configured MCPCBs for voltage-configurable LEDs like the LHP73B. Right now, anyone who wants to run the LED in 6V has to either buy a separate board elsewhere, or do a trace-cutting mod.
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Really the only argument for using a 6v LED these days is when driving multiple LEDs in series-parallel off like 3 or 4S batteries. Imalent, Fenix, Acebeam, and others do this on their very high output lights and it works great to keep thr input current manageable.
With 3V leds the input current is huge and really taxes the batteries quite hard even with tabless cells so a booat or boost/buck driver makes more sense. Fenix has proven that the sft90 in the new HT18 I tested outperformed the sft-70 version (6 volt driver), even though the output graph wasn’t as pretty.
There’s so many good 3v leds now that can provide high output, cri and tint without needing a boost driver or series battery. Plus, the electronics are cheaper.
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Interesting–I am not aware that boost-buck is a possibility for 3V LEDs. A driver that boosts when battery is low solves the problem of losing regulation at low battery levels.
I don’t know much about electronics–how hard are these 3V boost-buck drivers to implement, compared to a 3V buck-only (or 6V boost-only)? If this does not drive up the complexity too much, then maybe Simon should look into it.
I still think there is plenty of utility for 6V drivers, especially as many popular high CRI emitters like FFL/NTG 5050’s and SFT70 are only available in 6V. Same goes for 5700K 90CRI XHPs, which still have no 3V replacement in the same power class.
Just for clarity to make sure your post isn’t misunderstood: the current at the battery does not depend on the voltage rating of the LED, just the total power. The battery cannot tell the difference between a 6V 5A LED and a 3V 10A. Both draw 30W of power from the battery.
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Correct. The current at the battery is not the current at the led. You can drive the led at 5 amps, but you may be drawing 10 amps from the battery. Depending on how many leds or batteries, that input current can double, triple, or quadruple.
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There is an argument - they’re easier on the wires. And it’s less about voltage itself but also particular emitters - there is no 3V equivalent of SFT-70.2 or XHP50.3 HI with nice tint. There are smaller, larger, or nasty. I personally chose XHP50.3 HI R70 4000K over the LHP531 4000K after comparing them side by side - despite both being low CRI XHP was giving me much nicer, juicier colors. LHP emitters are lovely, rosy, balanced but also … pale.
How is the HT-18R proving anything? They changed the LED to SFT-90 which they pushed harder to get more lumens, they updated the battery from 5000mAh to 6000mAh to make up for it and it still produces less throw than SFT-70. Fully expected results that have absolutely nothing to do with voltage.
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I would really miss the boost drivers, they are currently the best affordable drivers for multimode green/blue/violet lasers…
Let’s say that 80% of the drivers I buy from @Simon_Mao are not for flashlights 
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I happen to have some samples produced by LMP that are similar to these two LEDs.
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Now you got me interested, can you spill some beans?
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Profile photo checks out.
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Only three Convoy Z1’s on this photo, with an average of 5.33 laser beams coming out of each 
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Lol
I suspect that the bottom of the reflector that is cut off doesn’t actually matter - as long as it is designed correctly. This is because:
- The hole should be located so the centre of the emitter surface is located right at the focal point.
- Then, consider that the LED only emits light forwards, not backwards. Therefore, the cut-off part of the reflector won’t receive light anyway. This is different to other applications such as an incandescent filament or radio antenna which can radiate backwards, and these are the rays that could be focused by the cut-off part of the parabola.
- This is, like you mentioned, provided that the gasket is properly designed and doesn’t block too much of the rays emitted more sideways.
For any given aperture diameter and depth of the reflector (excluding the cut-off part), there is only one real solution for the parabola, so the size of the hole (or diameter of the flat part at the reflector base, at least) is fixed and cannot be changed.
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