Looking further -

From a previous post on the subject https://news.ycombinator.com/item?id=42449068

> They measure at a certain point. Jason Cammisa points it out pretty clearly in an episode of Carmudgeon, with the money quote either here[0] or in the link direct to YouTube here[1]:

> On a recent episode of the Carmudgeon Show podcast, auto journalist Jason Cammisa described a phenomenon occurring with some LED headlights in which there are observable minor spots of dimness among an otherwise bright field of light. “With complex arrays of LEDs and of optics,” he said, “car companies realized they can engineer in a dark spot where it’s being measured, but the rest of the field is vastly over-illuminated. And I’ve had now two car companies’ engineers, when I played stupid and said, ‘What’s the dark spot?’ … And the lighting engineers are all fucking proud of themselves: ‘That’s where they measure the fucking thing!’ And I’m like, ‘You assholes, you’re the reason that every fucking new car is blinding the shit out of everyone.’”

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rootusrootus 5 hours ago | parent | next [-]

This highlights a problem in getting your information from a podcast or YouTube video, even when the presenter seems like someone you'd find credible.

No, the regulation does not measure lights at a single spot. The regulations are published and very easy to find.

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bayindirh 5 hours ago | parent [-]

I mean, Jason Cammisa is not some "YouTube person". He's arguably his generation's Jeremy Clarkson.

e.g.: https://www.youtube.com/playlist?list=PLHKCmmH-x9mIbtnKiNfg2...

He tells the stories, interviews with the people who built these cars (if possible), gets and drives a copy of the said car.

We're talking about a person who painstakingly perfects the pronunciation of the brand and model names just because he feels doing otherwise is not respectful for the brand, model and people involved with the car.

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Let's talk about specs. The spec[0] (pg 4) states that:

Photometers are placed at fixed locations on the test track to record the visibility and glare illumination of the test vehicle on each approach. To correct for changes in illumination that are due to changes in vehicle pitch, multiple photometers are used at each measurement location to capture illuminance readings at different heights. The illuminance readings are synchronized to the vehicle position and pitch using a common GPS time signal. The synchronized data are used to produce pitch-corrected illuminance versus distance curves that are used for the headlight rating. All data are processed using the DIAdem software package distributed by National Instruments. The processing scripts are available at https://github.com/iihs-hldi.

This is a fixed receptor, fixed path, multiple approach test and is susceptible to optimization of the illumination map designed by the car manufacturers.

Moreover, test document states that:

Illuminance data are collected with Gamma Scientific photometers (Part # U68401). The photometric sensors provide a very close match to the spectral response of the human eye. They are fitted with diffusers to reduce the illuminance measurements for off-axis incidence angles in accordance with Lambert’s cosine law. The sensors match the targeted cosine response to within 3 percent at angles up to 25 degrees, which is the maximum angle between the test vehicle and sensors on the sharpest curve (at distances greater than 10 m). The sensor signals are passed through a low-pass filter with a cutoff frequency of 35 Hz to allow for accurate measurements of pulse width modulated light sources such as LEDs. Each sensor is connected to its own transimpedance amplifier board that has fixed gains to yield a fast response while still minimizing linearity errors in the range of illuminance values for which the headlight ratings are assigned.

Again more places to optimize the headlight.

If the test finds the lights are "in-spec", and people are increasingly unhappy/uncomfortable, then something is wrong.

[0]: https://www.iihs.org/media/0e823704-32d1-4500-b095-15d064d82...

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potato3732842 4 hours ago | parent [-]

>He's arguably his generation's Jeremy Clarkson.

An entertainer who's keenly aware of what his audience demographics are, what they want to hear, what'll piss them off, and what he ought to be doing if he wants the money to keep coming?

I'm not saying he's lying, but all these guys have an incentive to say whatever it is they're gonna say in the way that makes their audience as hysterical as possible.

	▲	bayindirh 3 hours ago \| parent [-]
		Camissa is not as unhinged as Clarkson, their most common trait is their appreciation and knowledge of cars and how they treat their histories. Listening to Camissa makes me feel like I’m listening to someone who appreciates all cars for being cars. He has no biases and preferences like Clarkson (German cars being cold, Italian cars being awesome, etc.).

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bayindirh 7 hours ago | parent | prev [-]

Thanks for the info. I'm not surprised. Of course they are manipulating this test, too.