No type of bulb is getting banned, but allowed wattage to sell is getting regulated down. That’s why you can’t buy 100w, 75w, or 60w bulbs anymore but can buy weird 56w incandescents or something. If somebody makes an incandescent that produces 800 lumens it only 10 or 12 watts like that link suggests they’re perfectly legal to sell it.
Yeah, 10 watts for only 600 lumens seems like a lot, but looking at that spectrum there’s probably a LOT of phosphors on there. I wonder if a RRGB configuration exists for lower color temperatures like the RGBB configuration used to create high color temperature lamps. I’d think some thing like that would require less phosphor and be more efficient. What about just RG? Manually changing monitor settings to set blue to 0 doesn’t look THAT weird. Do we even need blue?
I really like the photometric reports that waveform have available. I wondered if the “vintage” style bulbs with the strings of LEDs coated in phosphor had any different spectrum than the snowcone style bulbs. We use a lot of the vintage bulbs because a lot of our fixtures are exposed and the vintage ones tend to be more tolerant of enclosed fixtures for some reason.
A minor point on an otherwise great post, but the 2015 paper about “Evening use of light-emitting eReaders” is an old ‘favourite’ of mine which should be handled with care.
Why? Because despite the frequent references to “LE-eBook” --which obviously makes one think of a Kindle Paperwhite, or similar-- the technology actually used for the study (as detailed in the Materials and Methods section) was actually… an iPad - so not a typical eBook reader at all.
(I’d lay a good amount of money that a Paperwhite set on fairly low brightness [#6-7 IME] would not give the same results…)
Welcome! And, yes, I did miss that.
However, I find that the Kobo Aura (which is “cool white only”) was nearly as bad, at least for me, as reading from an iPad or iPhone in the night.
I’m still reserving judgement on the Kobo Clara HD, which warm shifts, but it also has a “better enough” screen in terms of contrast that it’s a lot easier to read via background light.
I’ve got some “super red nighttime LEDs” on order to evaluate as well, though at $20+/bulb, they’re not exactly a compelling deal compared to just running incandescents…
I guess we’re dealing with three variables: brightness, size, and colour tone of a display, which together would influence the magnitude of problematic light reaching the eyes.
Are you aware of any research which correlates the brightness of a display (e.g. in nits) with the impact on sleep?
For example, assuming the 2015 paper used a 2015 iPad, it would likely have offered a full brightness of ~400 nits. It’s hard to find equivalent values for the Kindle, although this review suggested full brightness in the region of 78-92 nits. And my experience is that for reading in a dark room, I use a fraction of the available brightness.
Correct. My understanding of the issue is that it’s roughly a “total lumenous flux in the problem wavelengths” issue - brighter is worse than dimmer, longer is worse than shorter, etc. There have been some studies that look at shorter duration exposure, but the mechanism seems to somewhat saturate at some level - I’m not exactly sure where.
My Kobo, even dimmed, was enough to cause problems for me - though I’m still experimenting with the warm light on the Clara HD.
An odd link coming across Pocket favorites lately…
Perhaps more people are starting to figure this out?
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Reminds me how you get places online saying “humans are just slightly smarter animals” and then something like this comes up and suddenly “humans are totally different from all animals and they couldn’t be affected the same way!”
Hah, yeah. It depends on who you want to insult and what you want to justify continuing, far as I can tell. There certainly seems to be a lot of “comparable systems behaviors.”
Hacker News commentary was mostly trying to defend how you could really use LEDs and screens, as would be expected.
Do consumer LED bulbs with a high color-rendering index (CRI) emit more or less of a fraction of blue light than the common ‘extra warm white’ consumer LEDs - if there is a rule of thumb?
In particular, I am comparing:
a) Philips Master series, e.g. spec sheet master spec PDF
b) Philips CorePro CorePro spec PDF
Philips provides spectrum plots on page 2 in their PDFs. It is easy to see the ‘peak amount’ of light for a specific wavelength, but I find it hard to judge which one of them has a larger fractional area in the undesirable region 450-480nm.
(I am not interested in the actual color rendering quality - just want to minimize the fraction of blue light).
Sneakily, the high color rendering index bulb (Philips Master) changes its color from 2700K to a warmer 2200K when dimmed, but I am most interested in its full-power spectrum; unclear whether the spectrum plots refer to dimmed or undimmed.
Can anyone tell which one emits less blue light - is it likely to hold for other high color rendering index bulbs?
I would expect a higher CRI to correlate with more energy being moved out of the blues into the other chunks of spectrum, simply because you can’t get away with a massive blue spike and balance it out with red for a good CRI. However, I don’t know that any of them are particularly low blue, either.
Hah. I just opened the PDFs without really reading the links first, saw the spectrum for the Master series, and immediately knew it was a Philips by those goofy red spikes.
Of those two, I would expect the Master series to be somewhat lower in blue, though. That’s going to be the full power spectrum, almost certainly, not that it will shift much into the dimmed spaces - it will almost certainly just add more blue. This weekend’s post is on some Philips smart bulbs, and you can see some of the behaviors you’re curious about.
Though I’m working on my own algorithm for “blue percentage” and I suppose I should try to acquire a few more bulbs to test with.
I read the whole post and am scouring the 'net for incandescents as we speak. Something I would like addressed, though, is the supplementation of melatonin to combat the blue light effects.
I would imagine many are not in control of their lighting situation at least some of the time. (Night classes, shift work, etc.) Most institutional/commercial places just go with the cheapest (as in $/hr) option possible. I wonder if taking a melatonin supplement would offset or even negate the deleterious effects under such conditions.
eBay seems to still have plenty, including some “Not for sale in the US” bulbs cleverly disguised. The older 60W bulbs should pump out about 840-860 lumens.
I know it’s a thing, and it’s apparently a rather popular thing, but it’s fundamentally treating symptoms, not the causes. IMO. I’m aware this is how modern medical science tries to solve all known problems - mask the symptoms instead of treating the root causes. I can’t say I’m a fan of this approach, though.
There’s only so much you can do when you’re trying to invert the body’s natural schedule. I don’t know if supplements would help sleep during the day or not, though a friend is currently doing overnight shifts and is happy to experiment with stuff, so I may have him try it out. I’m trying to find a decent price on orange blocker glasses for him to try on his commute home in the morning - he’s 12 hours out of phase.
But, as I point out in the article, shift work comes back to the question of, “Is our technology serving the needs of humans, or are humans serving the needs of our technology?”
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Another thing that I suppose will end up with a separate blog post is the issue of LED flicker.
If you have a high speed cell phone camera, just… go ahead and point it at a cheap LED bulb. Watch it in high speed. It’s horrifying. Gobs of flicker.
You’ll also see some (far less aggressive) 60Hz flicker on incandescents - it’s on an AC waveform, so you’ll see that.
Credit to the claims made, the Bedtime Bulb, on slow motion footage, looks like a photo. It’s rock solid.
I have been following your light [pollution] articles with great interest and would like to ask if you have tried or spectometered the iOS colour filters in addition to redshifting?
It’s in Settings → Accessibility → Screen and text size → Enable → Toning → and dragging both sliders to as right as they go.
I originally saw the advice somewhere stargazing forum to help keep night vision and with the accessibility shortcut it has kind of became a habit for me.
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Interesting - I didn’t realize that existed! I poked with it and it certainly seems to redshift quite hard. If you turn intensity all the way up, it’s very much “just red” coming through. I’ll throw a spectrometer at it sometime soon and see, but it looks useful for iOS devices after sundown.
Thanks!
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