Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

LED lighting badly suppresses human melatonin production at night

sevarg.net

Post reply on HN
Print view View original

311–316 of 316 posts

Re: LED lighting badly suppresses human melatonin production at night

#311

Post by temp2022account »

_dan wrote: post #223
londons_explore wrote: post #185

Earlier quoted context omitted.

I am disappointed that many phones/tablets don't go very dim. From flagship to cheap, it seems that if you're in a pitch black room and check the time on your phone, the light will illuminate the whole room, even on the dimmest setting. I actually modded my phone by putting a resistor in the LED backlight circuit, which divided the brightness by 1000 - and it was still plenty bright at night (human eyes are logarithm…

A Macbook's minimum brightness is quite bright. The thing that annoys me no end is that if you hit the "dim" button when it's at minimum brightness, it goes black - but fades out slowly and smoothly. So they're clearly capable of being dimmer, but Apple decided we're not allowed that.

I have a small python script responsible for dimming my thinkpad + external display; it takes an argument like 'b * 0.95' for 5% reduction, reads HW + SW brightness, and lowers HW brightness to minimum before then reducing the SW brightness.

Pretty nice and the only recent change I've made is making it re-evaluate the expression based on frequency of keystrokes (so 3 brightness-down keys in 1s becomes 9 evaluated decreases in brightness).

Re: LED lighting badly suppresses human melatonin production at night

#312

Post by ilyt »

forgetfreeman wrote: post #289
ilyt wrote: post #232

Earlier quoted context omitted.

Uh, just no. LED lighting have modes of working that can be bad. You just need to be way more picky and knowledgable with LED lights which is hard for most customers, vs "just buy an incandesent bulb"

Nice "well actually" there. So is the proposal consumers perform their own spectrographic tests before making a purchase or can we just go with "leds are bad" given the overwhelming majority of the products available on the market demonstrate harmful characteristics with no clear way of discerning which are the outliers at time of purchase?

> Nice "well actually" there.

Learn to fucking read. I literally outlined problem in my comment:

> You just need to be way more picky and knowledgable with LED lights which is hard for most customers

And literally wrote that it is a problem to most customers.

So "well actually" fuck off

Re: LED lighting badly suppresses human melatonin production at night

#313

Post by ilyt »

londons_explore wrote: post #248
ilyt wrote: post #229

Earlier quoted context omitted.

> That means you need to be able to scale your backlight by a factor of 10^10 to cover the whole human vision range. Uh, phones don't produce brightness that high. And the low range is "too low" for usefulness anyway. Your math is off by few factors > And if your CPU runs at 1 Ghz (10^9), then at the dimmest setting then even being on for a single clock cycle would be a flash every 10 seconds - clearly unacceptable,…

Unfortunately at these low currents, you tend to get a tiny amount of leakage across the LED junction - just a few microamps, but trying to make a small amount of light it becomes an issue. Worse, you can't even calibrate for it because the leakage is highly temperature dependant.

shrug kindle manages.

Re: LED lighting badly suppresses human melatonin production at night

#314

Post by snshn »

rdsubhas wrote: post #283
snshn wrote: post #9

This is why OLED lights is the future: http://www.ioledlight.com/ and https://www.oledworks.com/

Doesn't OLED tech (in TVs, screens) also works by having a blue emitter with filters for white/ colors (which is what the article covers) ?

This is different. Those OLEDs are transparent, only have one emitter.

Re: LED lighting badly suppresses human melatonin production at night

#315

Post by forgetfreeman »

ilyt wrote: post #312
forgetfreeman wrote: post #289

Earlier quoted context omitted.

Nice "well actually" there. So is the proposal consumers perform their own spectrographic tests before making a purchase or can we just go with "leds are bad" given the overwhelming majority of the products available on the market demonstrate harmful characteristics with no clear way of discerning which are the outliers at time of purchase?

> Nice "well actually" there. Learn to fucking read. I literally outlined problem in my comment: > You just need to be way more picky and knowledgable with LED lights which is hard for most customers And literally wrote that it is a problem to most customers. So "well actually" fuck off

So you start with just no and then proceed to argue my point for me? Weird flex but ok. Anyway it's nice to see the quality of discourse hasn't degraded on HN over the years.

Re: LED lighting badly suppresses human melatonin production at night

#316

Post by grvdrm »

Paianni wrote: post #245
grvdrm wrote: post #238

Earlier quoted context omitted.

Interesting comment. I have a number of MR16 bulbs in my house that were previously halogen and are now mostly LED. They are a near constant source of frustration with bulbs burning out way too soon, some with what seems like wiring issues, a mix of incompatible switches, etc. Curious to hear what acceptable solution you derived?

Are they low-voltage lamps? (usually have a GU5.3 base). If they are powered by old transformers intended for halogen lamps it might be worth changing the transformers to ones meant for LEDs. Incidentally if there are dimmer switches in the circuits then those might have to be changed too.

Yea, 5.3 base.

Any thoughts on how to check the transformers? Is it as annoying as I assume because the transformer is hiding somewhere in the ceiling?

I've otherwise tried switch changes, but as you point out with the transformer, it might be that more than one component needs a change.

And maybe it's worth changing everything back to halogen!?

Post reply on HN