I have one of these… shoots a tight beam, i upped the power with a SFT-25R and a 8 amp driver..
Still just does get warm, so i know it can handle more.. but it takes a small 16-17mm pcb and driver..
I dont have a clue as to what other L.E.D.s would handle 13-15 amps and keep the beam i have now like the 25R does…
Would it mess me up going from 3535 to 5050 ?
Also.. are BoroFloat lenses worth it vs AR Tempered glass lenses ?
Unfortunately none. The 25R at 8A is essentially the upper limit of how much power density a state-of-the-art LED can handle without burning up. To keep the same beam profile in the same light, while pushing 13-15A, entails almost doubling the power density beyond what is technologically possible.
The only way to get the same beam and more power/throw is to use a different light with a larger reflector, paired with a proportionately larger LED (say SFT60).
For what purpose? They are sometimes preferred for low thermal expansion, but the heat generated by a light is pretty trivial for even regular glass to handle. Having a good quality AR coating that transmits well is a much more useful goal, and Convoy’s current glass windows (green-reflection AR) has by far the best transmission I’ve ever seen in AR coated glass, better than even nice binoculars I own.
If one wants the maximum shock resistance, acrylic or polycarbonate is gonna be better than any glass–glass is mostly for scratch resistance, which is a more relevant property in daily use that does not need to handle, say, recoil.
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Gotcha on the glass.
And on the LED.. i thought as long as you could keep it cool enough you could put more power to it.. to a point..
Would 10 amps be too much ? I know a few here have pushed a giving LED past what it was rated for.. but one wont get much more light for more heat..
Ok ill just keep it as is, its much better than it was to start with..
Thank you for the info..
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And im definitely not going bigger, this thing is already on the larger size for an AR-15 long range setup.. definitely not putting on my L21A on it lol.
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Intuitively, the more power you push through an LED, the more light you should get out of it. In practice, however, the marginal return per watt keeps diminishing and eventually becomes negative, due to a variety of reasons, the first of which being that the phosphor is saturated by the high density of blue photons. Beyond a certain flux density, the phosphor goes from converting blue photons to just absorbing them and releasing massive amounts of heat, leading to failure.
10A is way too much for SFT25R–its output peaks at 8A under laboratory conditions. Different LED datasheets are very different in how conservatively they rate the maximum power. The SFT40 3000K is only rated for 4A but handles 8A with no issue. On the other hand, the SFT25R is rated for 7.5A, and that is truly the maximum it can handle.
Also, chances are that a regular cell+driver cannot even supply 10A to a SFT25R, if its Vf rises beyond the battery’s voltage under 10A load.
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Just as with reloading ammo, pressure goes up, velocity goes up… to a point… then pressure starts to spike and gain very little in velocity..
Its responses like this that i learn.. thank you..
It is amazing to me how fine of a wire in the led and all that power..
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Also with lumens vs candela..
Lumens is how much light in total, candela is how intense the hot spot is.. in dummy terms..
Is that about right ?
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Precisely! The exact definition of candela is lumens per solid angle, which can indeed be thought of as hotspot intensity. It’s also common to see folks report candela as lux (lumens per m^2) measured 1m away from the emitting source.
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Yep. Good analogy.
And you go just a smidge past the point where gains are minimal, and things can get unhappy very quickly.
Its a damn shame what i spent for my Cyclops… now they have others at half the price, then i find a host over on Kaidomain for under $18 !!! Add another $20 and boom… you wanna talk about a thrower, with my SFT-25 and 8 amp it reaches. Just a small area at a time tho..
It looks like a SFT-40… and at a Claimed 2000 lm im going to assume 8 amp driver.
Streamlight Protac 2.0 HP.. what do you guys think ?
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The googz says it is an sft40. Most likely running around 6 amps for 2000 lumens.
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It looked just like my SFT-40. Just wasnt 100% sure..
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One more question. Bare with me on greenhorn questions and lack of understanding led’s and what power you can push through one.. im getting there.
In a C8, what led would give a tighter and possibly brighter hotspot than the SFT-40 and 8 amp i have now.. just not liking the hotspot size and very sharp outer edge..
Absolutely loving the SFT-60 in both the small Streamlight ProTac HL-X with 8 amps and the big L21A at 15 amps… starting to be my go to led…
This L21A at 15 amp gets warm but not bad at all, i can see it getting hot at 20 amp in short order tho..
Going to test run time tonight, using Reliance 6000mah batteries.
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SFT25R. Convoy’s current batch of 5000K SFT25R is amazing, essentially equaling the SFT40 in output but throwing much further. The forward voltage is also much reduced compared to previous batches, allowing for maximum throw to be sustained for a much longer time.
If you wish to use a 5050 emitter, Convoy also offers the 5050 W5050SQ5, which performs slightly worse than the SFT25R but is available in lower, nicer CCTs.
Unfortunately, the very sharp outer edge is unavoidable for reflector-based lights.
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Thank you very much..
Im i reading right when i see that wammer tints do better at higher powers ?
I like a whiter light but am i missing out on something ? I get it being a more natural light, but what are the performance advantages ?
If you prefer a neutral/cooler CCT, you should go for that! In terms of pure performance higher CCT usually measures higher than warmer CCTs.
Some folks see colors better with warmer CCTs. Also, for very long-range throwers (say 1km+ ANSI), warmer CCT produces significantly less back-scatter, which means (1) more of the light gets to the target, and (2) your view of the target is less obscured by the beam. The longer the throw, the more pronounced this effect.
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Awesome thank you oh flashlight swami.. no really, thanks. Really glad to have been recommended here by Lumencraft..
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Just replaced the SFT-40 to a SFT-25R in my C8 and left in the 8 amp driver, on a wall it has a messier hotspot, but shining my backyard it has a tighter beam and seems a bit brighter.
Also swapped out the OP to a Smooth reflector, XPG2 for a SFT-25R in my T2 and left in the 1.5 amp driver, as i wanted to still be able to use 1.5v alkaline and that made for a good improvement..
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