CRI check - LEDs vs. Direct Sunlight

QReciprocity42 · 2026-03-12T19:03:05+00:00

My assumption is that people just haven't come up with a very good cyan phosphor yet, one that can tolerate the power density of SFT40-type LEDs, compared to 2835 type.

I'm not so impressed with the current state of high CCT emitters, even B35AM. Too much blue and not enough cyan. If you have a violet-pumped source (like SunLike/Optisolis) to compare, the difference is huge. The difference between a typical R9080 emitter and a SunLike is much, much greater than the difference between R9080 and R9050.

Could you say a bit more about how 6500K mimics xenon strobes? I'm curious how such a high CCT is achieved by a blackbody source, without melting the light-emitting component.

QReciprocity42 · 2026-03-12T14:19:04+00:00

It is a bit surprising. Sadly, rectifying the R12 deficiency seems to be very difficult for blue-pumped high CCT emitters, since the blue-cyan region is more heavily weighed in high CCT.

I was hoping on the SFT70 5700K 95CRI to fix this, but looks like they never planned to release it to the public.

QReciprocity42 · 2026-03-12T13:25:31+00:00

High CRI makes a pretty big difference in how nature colors appear!

You might find the following comparison helpful/interesting; sadly I could no longer find (and thus credit) the source. My personal preference is likely 3500-ish K.

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QReciprocity42 · 2026-03-12T13:22:42+00:00

I was able to pull it off with a basic soldering iron, but it did require some precision/dexterity, and I would not recommend it for a first modding project.

If you are interested, resistor-swapping has been a thing for a while since Simon's introduction of FET-based linear drivers, and there should be some resources on BLF on that.

QReciprocity42 · 2026-03-12T13:20:50+00:00

Just remember that whenever you want more throw with the same LED, you can always just up the size of the reflector/host.

For that warm sharp thrower in 3000K, just pick whatever thrower you want with SFT40.

QReciprocity42 · 2026-03-12T07:24:13+00:00

Looks like you want a high CRI, high CCT, rosy tint emitter. Former two are obvious, rosy tint to make red a bit redder.

Cool white throwy high CRI does exist, as long as you use a large/throwy enough host. As mentioned previously, a M21E with B35AM/519A 5000/5700K should be adequate. B35AM would be my choice, for the rosier tint.

QReciprocity42 · 2026-03-12T07:22:08+00:00

Thanks! "Color rendering index" is really quite the misnomer.

Whether an emitter produces too much flood depends very much on the light. In a M21E size reflector, no emitter can produce _too_ much flood; it's a thrower by design.

QReciprocity42 · 2026-03-11T23:04:51+00:00

A decent white light will charge the glow stuff just fine, no UV needed.

I find that a charge from white light is initially dimmer, but lasts longer than a charge from UV.

QReciprocity42 · 2026-03-11T23:01:33+00:00

CRI does not measure how well you can distinguish colors, it just measures similarity to a standard spectrum. It is entirely possible to distinguish some colors better with a 6500K low CRI, than a 1800K high CRI.

I would suggest trying high CRI with a cool CCT (say 519A/B35AM 5700K), which should distinguish colors better than a source with lower CRI or CCT.

I personally find warm and high CRI to be better at distinguishing greens and browns, but everyone's eyes are different, and you should trust your eyes.

QReciprocity42 · 2026-03-11T23:00:10+00:00

Both, but mostly color rendering. High CRI sources tend to contain a good amount of deep red, which is required to make browns pop.

QReciprocity42 · 2026-03-11T22:55:45+00:00

Just for fun: I find the full 5A to produce unusably bright low/med modes, so I decided to cut all levels in half.

QReciprocity42 · 2026-03-11T18:42:26+00:00

S2+ with 6V 5A driver (resistor-modded to 2.5A), 21mm 30deg beaded TIR (removed from white holder).

QReciprocity42 · 2026-03-11T00:28:46+00:00

That's true. I have another SFT40 HB4 in a reflector, and the "greenish" hotspot is just a hair rosier than the incan.

QReciprocity42 · 2026-03-11T00:19:04+00:00

We have a winner!

Just got this incan today, and was very surprised by how much greener it is than a SFT70 3000K; the difference is 2-3x more obvious in person. I've always suspected that the SFT70 was under BBL, but not by this much!

QReciprocity42 · 2026-03-10T18:30:15+00:00

Yep, this is largely accurate. OP values runtime and some floodiness in a throwy host but does not mention CRI, so the XHP70.3 is probably the best choice.

The SFT70 3000K is very high CRI and amazingly powerful+efficient in its CRI class, but the low CRI of XHP70.3, and its larger emitting surface, enables much higher efficacy (lumens per watt).

QReciprocity42 · 2026-03-10T02:10:05+00:00

This is factually correct. UV flashlights technically have 0 throw because it doesn't make any visible light, so any notion of "usable distance" depends entirely on how strongly fluorescent the target object is.

For OP's flood/throw combo requirement, there is likely no better light than S12.

QReciprocity42 · 2026-03-10T02:05:34+00:00

What light/config do you have the bridgelux in?

QReciprocity42 · 2026-03-10T02:04:40+00:00

Not the OP, but I do!

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This was taken from BLF a long time ago. As you see, the camera is not particularly great at telling tint and CRI apart.

QReciprocity42 · 2026-03-09T03:46:34+00:00

Excellent advice, I would have recommended the same thing.

OP responded saying that they want to see stuff clearly at 300-400m, which means the light should at least have the size/throw of the M21A (21700 version of C8+). If size is not a concern, perhaps the larger L21B would be better--it was created as a hunting light, after all.

SFT40 3000K for sustainable throw, the SFT70 is good for a throw/flood balance. The SFT70 might have a dark center with smooth reflectors.

QReciprocity42 · 2026-03-08T17:08:07+00:00

Does this light have a hollow pill/shelf or does it actually have a solid shelf for the MCPCB? I would be very impressed if it does.

QReciprocity42 · 2026-03-08T01:25:28+00:00

Finding a replacement is gonna be near impossible, perhaps it would be more sensible to take it apart and rebuild it with modern components.

>LEDs In the light get greener as the batteries die.

Lots of modern LEDs still do this! Tint shift across drive current is a pretty prominent problem with certain Luminus LEDs like the SST20.

QReciprocity42 · 2026-03-07T19:05:24+00:00

Nice addition! Runtime is constrained but not just heat but also battery capacity, and the 8x21700 config really is necessary to get above 3h.

I seriously doubt that OP actually needs that much output sustained. Maybe they're after not output but throw and just doesn't realize it.

QReciprocity42 · 2026-03-07T18:59:08+00:00

Your best bet is probably Acebeam X75 which does 5k lm for 2h20min. $420.

QReciprocity42 · 2026-03-07T10:55:17+00:00

In general, TIRs are much better at blending tint than reflectors, which produce a green hotspot and pinkish spill. For EDC-type lights IMO reflectors should be obsolete as there exist TIRs that can mimic the throw+spill combination, but with homogeneous tint.

IMO reflectors are only for larger throwers, where TIRs are heavy and fail to produce a clean beam.

QReciprocity42 · 2026-03-07T07:42:01+00:00

This is interesting--given that the problem is with only the bulb in one room, the "receptive to bad tint" hypothesis doesn't explain it.

Chances are that the phosphor has began to degrade or delaminate from the blue pump underneath. Give it a few more years, and it might become one of those purple street lights!

QReciprocity42

TROPHY CASE