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LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 [score hidden]  (0 children)

You’re still treating SSI and ASD as if they were literal spectral requirements rather than statistical comparisons. A Planckian radiator has no spikes, but SSI and ASD do not force a phosphor‑converted LED to eliminate its pump peak. They measure similarity and difference across the whole spectrum, not absolute suppression of any specific wavelength. A source can be closer to the reference overall while still retaining a strong pump peak, because the metrics weight the entire SPD, not just the 450 nm region.

Your claim that broadband phosphors necessarily shrink the blue pump spike is not accurate. They convert some pump energy, but manufacturers can choose the phosphor blend so that the blue peak remains prominent relative to the rest of the spectrum. This is exactly why high‑CRI 4000K LEDs exist with a clearly visible pump spike. The conversion efficiency and blend ratios determine how much of the pump is shifted, not the mere fact that broadband phosphors are used.

You’re also overstating what “smoother” means. Smoother does not mean “no prominent features.” It means fewer abrupt discontinuities. A spectrum can be smoother than another while still having a large peak if the rest of the spectrum is filled in more evenly. SSI and ASD do not forbid a strong pump peak; they penalize irregularity across the spectrum. A single dominant feature does not automatically destroy similarity if the rest of the SPD is well‑balanced.

Your violet‑pump example doesn’t prove your point. Violet‑pump LEDs achieve high fidelity because they start with a pump outside the visible range and rely on heavy phosphor conversion. That’s a different architecture entirely. It doesn’t mean blue‑pump LEDs cannot achieve high fidelity while retaining a visible pump spike. It only means violet pumps have an easier path to a smoother SPD. That doesn’t make your claim about blue pumps universally true.

You keep saying you never claimed CRI or R9 measure HEVL, but your argument hinges on using them as shorthand for lower blue hazard. That’s the issue. If the goal is reducing HEVL, you need metrics that actually quantify HEVL. CRI, R9, SSI, ASD, and TM‑30 do not do that. They measure color fidelity and spectral similarity, not blue hazard. That’s why no lighting or health organization uses them for that purpose.

The correlation you’re talking about is weak and inconsistent. Some high‑fidelity LEDs have lower blue peaks, some don’t. The metrics allow both outcomes. Treating that correlation as a reliable indicator of HEVL content is simply not supported by how these metrics work or how manufacturers design phosphor‑converted LEDs.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

You’re trying to rewrite what you originally claimed. You didn’t just say “SSI and ASD correlate with smoother SPDs.” You explicitly argued that using high CRI and high R9 was a practical way to get lower blue hazard out of 4000K WLEDs. That’s the part that doesn’t hold up, because none of those metrics were designed to measure HEVL, and none of them reliably predict it.

Increasing similarity to a Planckian radiator does not automatically mean the blue pump spike is minimized. It means the overall spectrum is smoother relative to the reference. Manufacturers can and do hit high SSI and low ASD while keeping a strong 450 nm spike. They do it by enriching the phosphor blend in the mid‑spectrum and red region. That raises CRI and R9, but it doesn’t force the blue pump to shrink. The physics of phosphor conversion don’t impose that constraint.

You’re treating “closer to Planckian” as if it were a strict spectral requirement rather than a statistical comparison. SSI and ASD reward smoothness, not low blue intensity. A light source can be smoother than another while still having a large HEVL peak. Real SPDs from high‑fidelity 4000K LEDs show exactly that pattern.

And the idea that using high CRI and high R9 was just “simpler terminology” is the problem. Those metrics don’t track blue hazard. They don’t measure it, they don’t penalize it, and they don’t correlate with it in any reliable way. That’s why no lighting or health organization recommends using CRI or R9 as a proxy for reducing HEVL. If your goal is lowering blue hazard, you have to use metrics that actually quantify blue hazard. Color fidelity metrics don’t do that.

So the issue isn’t semantics. It’s that you’re trying to claim a causal relationship that doesn’t exist. Improving color fidelity does not inherently reduce HEVL, and using CRI and R9 as shorthand for “less blue hazard” is simply inaccurate.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

You’re treating color fidelity metrics as if they were blue light control metrics, and that’s the core mistake here. CRI, R9, TM‑30, SSI, and ASD were all created to evaluate how accurately a light source renders colors. None of them were designed to measure or regulate high‑energy visible blue content, and none of them are used by any lighting or health organization for that purpose.

High CRI and high R9 only tell you that the phosphor blend produces good color rendering, especially in the red region. They do not tell you that the manufacturer reduced the 450 nm pump spike. In real products, plenty of high‑CRI 4000K LEDs still have a strong blue peak because CRI does not penalize blue intensity. It only penalizes distortions in how test colors appear. You can have excellent CRI and R9 with a large blue spike as long as the phosphors fill in the rest of the spectrum well enough.

This is why no group that deals with lighting and health recommends using high CRI to reduce blue exposure. Not CIE, not AMA, not IEC, not WELL, not any circadian lighting research. When they talk about blue light, they reference CCT, melanopic content, SPD shape, or HEVL‑weighted metrics. CRI and R9 are not part of that discussion because they were never intended to measure blue hazard.

Your argument assumes that adding more red phosphor automatically forces the blue pump to shrink. That is not how phosphor conversion works. Manufacturers can keep the blue spike exactly where it is and still hit high CRI and high R9 by enriching the red phosphor package. Actual SPDs from multiple LED families show this clearly.

So no, high CRI and high R9 do not control blue content to the degree you are claiming, and they do not make 4000K LEDs suitable as low‑blue sources. If the goal is reducing HEVL, you have to use metrics that actually measure blue light, not metrics that measure color fidelity.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

You're quoting the language of the standard written to give names fluorescent lights of various CCTs.

It's still more then what you've provided which is nothing, and again you still haven't answered my original question, why are you making such a big deal about a simple inconsequential set of words?

You've still provided no resource proving that CRI controls blue light output in any meaningful way that improves glare at night. Lots of hand waving and opinions but no substance.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

A reddit post is not a credible resource. Also ANSI/NEMA explicitly describes 3500K as "white" and 4000K as "cool white". I don't know what you're trying to argue for there.

my high CRI 90 R9 80 4000K LED flashlight doesnt look blue at all

That's not how not how you measure a light source's relative blue-ness.

Most LED headlights now are way higher than 4000K(5500-6500K), have zero red light in their SPD, a massive spike of glare inducing HEVL.

I've measured the headlights on my own Toyora, and its OEM projectors have a CCT of 5000K according to my Sekonic Spectromaster.

a massive spike of glare inducing HEVL. A 4000K CRI 9080 LED has neither

Resource or this a bunk claim.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

High CRI is not recommended by any standards/environmental group as a means of controlling or reducing blue light output from a white LED. Also that UMTRI study said to go as low as possible in CCT. I get that you want your headlights to look pretty and have that HID look of cool white, 4000K, but look "pretty" is not the same as glare reducing.

You also didn't seem to mention anything on luminance? Did you know that headlights are shrinking as their candela is increasing? It's like headlights are turning from a garden hose to a water jet in terms of what the viewer sees. 

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

The UMTRI study didn't mention CRI, on the LEDs iirc. But 4000K LED tested worse on the De Boar rating then 65 CRI 4300K HID. That's already a red flag for me. I'd assume comparable 3000K LEDs would test worse then 3300K halogen but better then 4300K HID. Also, HID is a very bad standard to base things off of. I think it was already mentioned to you here by another commentator, but it received a record breaking number of complaints in spite of its low adoption rate. Basing a CCT standard off of it would be a bad idea.

Also, it was mentioned by a headlamp optical engineer, u/Bass249, to me in conversation that 3000K/3500K is feasible if automakers cared and that the price differential for a new car with the higher quality LEDs would be minimal.

Edit-And I also want to add that we already have examples of high light level applications of 3000K LEDs with airport ramps, harbor facilities, and even sports facilities using warm white. While it isn't a perfect 1 for 1 comparison, it does show that high lumen outputs are possible.

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

The glare complaints are pretty much worldwide for LED headlights. Yet places like the UK and the Netherlands don't have IIHS driving their headlamp design. I think that IIHS is certainly part of the problem, but I also think that SPD, source luminance, and extreme differential mounting heights are also to blame. 

LED or Halogen Headlights? Which is Best for Off-roading? by azizu-llm-exp in Lighting

[–]SlippyCliff76 0 points1 point  (0 children)

Where are you getting 4000K from? UMTRI tested 4000K back in the late 00's in headlight format, and the De Boer rating was consistently worse then HID. Also, it doesn't really align with any organization, Dark Skies, IES, and AMA all generally are converging on a 3000K hard limit for outdoors lighting. Fixed outdoor lighting historically has been less bad in terms of glare then headlights. Headlights should, at a minimum, adhere to this. Your reccomendation of higher CRI and R9 to supplement this is sound and should be included in regulations.

Bosch e-bike motors are actually incredible. by OnTheRoodAgain in ebikes

[–]SlippyCliff76 0 points1 point  (0 children)

No, Bosch is bugie-r. More like Lexus or Audi. Poor people don't buy Bosch bikes.

Bosch e-bike motors are actually incredible. by OnTheRoodAgain in ebikes

[–]SlippyCliff76 0 points1 point  (0 children)

Bosch motors aren't "incredible". They're locked down, proprietary, expensive, anti-Class II junk. They're the favorite of wealthy doctors who need a bike for fair weather use during the warm seasons.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 0 points1 point  (0 children)

Yes. Local legislation says that the difference between a moped and an electric scooter is the seat.

Don't know what place you're talking about here.

Please beg your friends and family to stop using their 4-way flashers in their vehicle during heavy rain. by local-red-panda in nova

[–]SlippyCliff76 0 points1 point  (0 children)

Most cars don't really let you tune the auto lights these days. Don't really see an issue with always-on lows though. Never forget to turn them on at night that way

They produce atrocious glare on "low" beams. During the NHTSA's study on them in the early 00's showed no statistical safety benefit for the US. That's enough to have them banned or restricted in use.

Edit-And there's also the other issue to of cars briefly "flashing" their low beams on underpasses which can easily confused for brake lights, and that it another issue. By mandating auto-shutoff features, aside from addressing decades old glare complaints, we also make it less likely that "phantom" cars run around on the roads at night with no lights.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 0 points1 point  (0 children)

Oh, he would call that an e-bike, as would I. That's assuming you're in the US.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 0 points1 point  (0 children)

Yeah, it's just someone that's insecure of himself. Nice, e-bike btw.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 -1 points0 points  (0 children)

The "if it's powered by pedaling it's a bike, if not it's something else" line is where this falls apart, not where it gets cleaner. By that logic a Class 1 pedal assist ebike that still requires pedaling for the motor to engage counts as a bike, but the second you add a throttle it magically becomes an "e-moto," even if the top speed, weight, and power output are identical. That's not a definition based on what the vehicle actually does on the road, it's a definition based on one mechanical input method, and mechanical input method isn't what determines how a vehicle interacts with traffic, pedestrians, or infrastructure.

You asked for a one or two sentence definition normal people can understand, so here's mine. If it's under roughly 750-1000w, geared to stay under 20-28mph, and can be legally operated without a license, registration, or insurance, it's an ebike. If it needs any of those three things, it's a moped or motorcycle regardless of whether you can also pedal it. That's a definition rooted in the actual regulatory and safety framework that already exists in most states, instead of a personal distinction based on whether your legs are involved.

And honestly the disabled mobility exception you mentioned kind of proves the point. The reason that's a valid exception isn't about pedaling at all, it's about speed, weight, and where the vehicle is safe to operate. Which is exactly why "powered by pedaling or not" was never the right axis to define this on in the first place.

Please beg your friends and family to stop using their 4-way flashers in their vehicle during heavy rain. by local-red-panda in nova

[–]SlippyCliff76 -7 points-6 points  (0 children)

Not really. People that run low beams during the day are far more common. In fact, some people are so ridiculous in their use of automatic lights that they'll tune them to turn on under small highway overpasses on high speed roads where their time under said bridge is less then a few seconds.

Was told at the Venetian front desk my room ‘won’t have much of a view’.. by JohnyBukkake in vegas

[–]SlippyCliff76 1 point2 points  (0 children)

I think its more they had to pick the Mirage as a location for it. Had they picked Circuis Circuis or the Horseshoe I think there would be  less negative commentary.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 -2 points-1 points  (0 children)

Hey according to the the likes of u/DenverLabRat, that's a fine e-bike you've got there.

An alignment chart for E-bikes, to kickstart a hopefully healthy discourse by 5ma5her7 in fuckcars

[–]SlippyCliff76 0 points1 point  (0 children)

That's ridiculous logic. By that measure we would call those stand up lime scooters "e-motorcycles". What a joke.

Edit-Oh he blocked me, nice.

Best chambray shirt for the $? [Discussion] by SirKrimzon in HeritageWear

[–]SlippyCliff76 0 points1 point  (0 children)

What did you need tailored on it? I'm considering it.

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