For someone who has no idea about light engineering or electronics if I stack two 25k Lm lamps next to each other does it make 50k Lm light?

I recently changed my car's headlamps to Chinese LED which claims to be about 37kLm and I don't know how much it is probably less than that.

Two of those lamps costee me around $24 on Amazon US (pretty sure under $10 in China).

What makes this $800+ ?

Please don’t put in extra bright headlights on cars. Stock LED headlights being to bright for other drivers is already a massively common complaint — and then we have people installing even brighter ones? Please don’t.

For colours to look natural you need your white light to contain lots of different wave lengths. It’s usually measured as Ra. Artificially looking LEDs are easily 10x cheaper than photography grade LEDs. Also, this guy is probably paying taxes and handling stuff the proper legal way. If you order from Alibaba, chances are you’ll not be paying taxes. Plus if they offer a 5 year warranty, they probably need to keep some money around for repairs.

In addition to the all the other stuff, including light spectrum differences, you can't just trust that a "37000 lumen" light (cheap from China ...) is such a thing. Some examples of "100,000 lumen" flashlights that ended providing more like 2000 to 3000 lumens: https://www.youtube.com/watch?v=6q_0wxzClkg

It's possible, they exist, many such LEDs are probably manufactured in China ... but the legit ones are probably more expensive, and you may need a more recognizable brand to do some QA, and keep pressure on the factory to not slip quality or inputs.

Consider the cheap screwdriver included with the lamp in this story: unexpectedly, many were more faulty than the cheapest $4 screwdriver you'd find in any hardware store. The more stories you read about manufacturing stuff in China, the more you'll see very strange things. It's not about nationality or anything, it's an extreme kind of optimization. If you didn't catch it already, maybe you didn't really need what you thought you asked for ... they're just checking/optimizing

Yep lumens are additive (though your eyes perceive them logarithmically).

I don't know much about car headlights, but chatgpt says high beams are typically 25-45 watts, and assuming a generous 200lm/w that gives you 5000-9000 lm.

Roughly speaking, it's expensive because it's 50 lbs & tons of electrical components (that are much higher quality than $24 headlights).

> claims

That's all there is to it. Take a look at https://www.youtube.com/watch?v=5CJqAJ2LXw8&t=852.

Just to add context those are just dumb lamps and I acknowledge that the product here has a lot more features including IoT support and the ability to change Hue.

Is it the ability to change Hue that makes this expensive?