
You Need More Lumens - ivank
http://meaningness.com/metablog/sad-light-lumens
======
sambe
A recent Cochrane review found very little high quality evidence in either
direction:

[http://www.cochrane.org/CD011269/DEPRESSN_light-therapy-
prev...](http://www.cochrane.org/CD011269/DEPRESSN_light-therapy-prevention-
winter-depression)

It's not clear to me why light therapy is considered as a well-researched
treatment.

~~~
Loic
From the review, they found 2986 unique papers on the subject, they then
assessed 91 papers from the 2986. From these 91, only 1 had a rigorous double
blind testing but on only 46 people. The exposures for the light source was
2500 lux, IR light and no special treatment. The results were not significant.

So, lot-researched but maybe not well-enough researched.

~~~
bradleyjg
How do you go about blinding a study which does or does not shine a bright
light in subject's faces?

~~~
MengerSponge
I'm guessing you vary the intensity and spectrum of the light. If the
treatment doesn't show a dose-response curve of some kind, then it probably
just doesn't work.

 _Standard academic disclaimer applies_ : This isn't my field of study, and
I'm sure there are many subtle mistakes in what I just said.

~~~
tacos
A quick Google confirms this: they use either an identical-looking light with
a different response, or a different light altogether. "Here's a light, here's
a sugar pill, log your mood please..."

As silly as that all sounds, it's already a million times better than what
this guy did. He took the "if a little is ineffective a LOT will be better"
approach and built a damn lighthouse in his living room. And if the goal is a
DIY project and a blog post, OF COURSE you'll feel better after "your
treatment." It's approaching group therapy at that point. There's a lot of
this crap on HN lately.

~~~
dota_fanatic
I don't think that would actually be a million times better.

If we want to get to the reality where confidence in the efficacy of things is
well-founded on rigorous experimentation and analysis, then we need to get
there, one step at a time. Instead of tearing people down and saying that
their efforts to improve themselves is crap, you could be offering
constructive criticism. Even just bring up one question that would have made
it a better experiment, so that when a reader here decides to copy him, they
can do it better. Maybe they'll even share their personal experience and
propagate more experimentation? If enough people do that, maybe collectively
we'll one day have the interest and funding to have better studies done.

Would you rather he have not done the build, not shared it with the internet?
Maybe he could have been more like the status quo and consumed someone else's
product, quietly?

This post and your post yesterday where you argued 2700K screen temperature
late in ones day is NOT less straining than 5800K, because if that were true,
movie theatres would play all their movies with screens at 2700K... makes me
think you're not really interested in people improving their quality of life,
you just want to argue.

~~~
tacos
Author anonymously makes unsupported claims, disparages competing products,
provides no science, and wrote the post for profit. Nothing can be built on
this, because his work is built on sand. "Type up a blog post" is not the
important part of the scientific method. Pointing out pseudoscience and
invalid methods and data may be the most constructive criticism of all.

Enthusiasm is great. Enthusiasm masquerading as medical treatment is not.

~~~
jschwartzi
> "Type up a blog post" is not the important part of the scientific method.

How do you think all those legitimate scientific journals got started? It's
natural to think that because science is currently done with a huge amount of
rigor that it was always done with a huge amount of rigor. In truth, the
author's approach is still very scientific.

He considered the research he had available to him, reviewed some of the
science regarding different lighting technologies, then tried something and
observed that it worked. What about that isn't scientific?

Every scientific pursuit started out as a pseudoscience. Even the most
rigorous fields like Physics or Medicine were originally people intuiting
about a phenomenon with each other. There's nothing unscientific about what
the author did, and to me it raises far more interesting questions than a
diatribe about a lack of rigor.

~~~
tacos
> How do you think all those legitimate scientific journals got started?

The founding history of scientific journals is often amazing, involving
legends in the respective fields. Then over decades those journals became
"legitimate" by not publishing crap.

> Every scientific pursuit started out as a pseudoscience

I don't think that word means what you think it does.
[https://en.wikipedia.org/wiki/Pseudoscience](https://en.wikipedia.org/wiki/Pseudoscience)

------
windsurfer
This review for the linked led strip is interesting:

 _This is a perfectly usable (and subjectively bright) LED strip, but beware,
the specified lumens are a lie. My power meter reports a draw of 33W and
another reviewer reports ~38.6W. The maximum efficiency of a 5730 SMD LED is
~110 lumens /watt, so this strip is outputting at most ~3630 lumens. Seller's
description of "45-50LM" per LED would lead you to believe this can output
15000 lumens or ~454 lumens/watt. This is far outside the world record 200
lumens/watt bulbs and even outside the theoretical physical limit of 250–370
lm/W._

~~~
ivank
I posted a little further investigation at
[http://meaningness.com/metablog/sad-light-
lumens/comments#co...](http://meaningness.com/metablog/sad-light-
lumens/comments#comment-774)

>
> [http://electronics.stackexchange.com/questions/51778/](http://electronics.stackexchange.com/questions/51778/)
> suggests that these LED strips have to be overvolted and powered at multiple
> points, which might bring them closer to ~7000 lumens.

> I'm also going to try comparing the hkbayi Super Bright to LEDMO's strip
> with 600 LEDs:
> [http://www.amazon.com/dp/B013C2U09S/](http://www.amazon.com/dp/B013C2U09S/)

~~~
jacquesm
I have on of those Super Bright led strips in the kitchen and it is actually
too bright for direct lighting uses. You end up with afterimages for minutes
on end after just glancing in their general direction. Would recommend you
only use these for indirect lighting applications.

------
jensen123
I live in Norway, and used to have a big problem with SAD and longer-
than-24-hour-cycles. I tried a few of the commercial lamps like he did, and my
experience was similar. They helped some, but not enough.

My current solution is to take a 1 hour walk outside every day around noon.
Also, I've stopped sitting in front of my computer or TV 3 hours within
bedtime. Instead I usually spend my late evenings reading paper books.

This has solved the longer-than-24-hour-cycles and most of the SAD (it also
seems to have completely cleared up my acne). However, on days when it's
overcast and kinda dark, I still notice some SAD. On those dark days, the kind
of lamp that he built probably would have been nice.

~~~
dorfsmay
Interesting, in Canada we're told that the angle made by the sun in winter in
places at "high" latitudes (> 50) prevents us from getting the right kind of
light/UV in the winter, and to compensate by taking daily supplements of
vitamin D.

~~~
sliverstorm
You just need more sunlight. At tropical latitudes you get enough D in five
minutes with only your face exposed. At northern latitudes it just takes
longer, or you can expose more skin.

~~~
jensen123
If the sun is very low in the sky, no UVB radiation will reach you. The body
needs the UVB radiation in order to produce vitamin D. I think a general rule
of thumb is that if your shadow is longer than you are, then there is no UVB.

------
buro9
You could just purchase stage lighting.

Stage lighting fixtures use the halogen metal iodide bulbs that he salivates
over at the end, and already solve all of the issues he outlined. They provide
their own ballasts, are metal shielded, use a lens that acts as a UV shield,
have built-in cooling.

In fact the only issues with stage lighting:

1) The cooling wasn't designed to be silent (it isn't expected to be near
someone in a near-silent environment)

2) The lamp casing wasn't designed to be near anything flammable (they get
very hot)

3) The lens and casing is designed to throw the beam in a very small angle of
spread over a reasonably long distance (they're not designed to point at your
face from a few feet)

But given that, it seems reasonable that one could put it farther away and
reflect it into the space you want lit.

And if he really wanted to go crazy whilst staying with LEDs, then he could
just get a few of these: [http://pulsarlight.com/products/chroma-
range/chromaflood200/](http://pulsarlight.com/products/chroma-
range/chromaflood200/) which are used in architectural lighting and each one
produces 10k lumens, and they are safe for indoor and outdoor use, are
waterproof, and can be driven from standard mains power.

~~~
cauterized
There's another issue with stage lighting, which is that they draw enough
power to flip most residential circuit breakers and possibly to cause
electrical fires as well. You're looking at 500W per lighting unit; 575W for
the more modern ones with bluer hue. Most theaters are specially wired from
the mains to a bank of "dimmers" that safely provide at least 2000W per
circuit.

~~~
Symbiote
That should be no problem in Europe, Australia, etc. There are portable 3000W
appliances, like kettles, heaters and (Old) vacuum cleaners.

~~~
cauterized
I had no idea! In most kitchens here you can flip the circuit breaker by
running the microwave and toaster at the same time. I've also occasionally
done it by turning the oven light on while both (gas) oven and microwave were
in use. Sigh.

What does a kettle need 3000 watts for?

~~~
andrewaylett
Boiling water?

3kW isn't a magic number for the kettle, it's just the amount of power you can
get away with drawing when you've got a 240V supply rated at 13A. The more
power, the faster the water boils.

As I understand it, freestanding kettles are much less popular in North
America, presumably because a hob can draw more power?

~~~
sliverstorm
North america just doesn't use as much hot water as Asia and Britain. No tea
or instant foods. Pasta must be boiled, coffee is usually made in a dedicated
device...

~~~
moogly
I (and I thought most people) preboil pasta water in a kettle. Then I can
start cooking the pasta within 2 minutes instead of 15.

~~~
polynomial
How does this work? If you are using the exact same heat source, then the only
difference seems to be the metal/composition/thickness of the kettle vs. a
cooking pot. Which doesn't intuitively seem like it will save 13 minutes out
of 15.

~~~
Symbiote
You'll always save time with an electric kettle — it's likely to be better-
insulated, have a lid, and the heating element is in contact with the water.
It will still take 4-5 minutes though, even with a powerful kettle.

In case you're not familiar with them, we're discussing something like [1],
or, to show these are very widespread commodity appliances, [2], which costs
$7 including tax.

[1] [http://www.amazon.co.uk/Andrew-James-Cordless-Indicator-
Warr...](http://www.amazon.co.uk/Andrew-James-Cordless-Indicator-
Warranty/dp/B00LA4BPXQ)

[2]
[http://www.argos.co.uk/static/Product/partNumber/9016710.htm](http://www.argos.co.uk/static/Product/partNumber/9016710.htm)

------
julianpye
As a teen on weekends I worked a lot on filmsets as assistant to a lighting
cameraman. Switching HMI lamps on was really amazing, the mood of the set
changed in an instant. It was quite energetic, so I completely get what the
author is saying. They usually were positioned outside of windows, allowing
for a stable consistent sunlight simulation across scenes.

~~~
vanderZwan
From the wiki article[0] on HMI lamps:

> _85–108 lumens per watt of electricity._

Sounds pretty good!

> _With HMI bulbs, color temperature varies significantly with lamp age. A new
> bulb generally will output at a color temperature close to 15,000 K during
> its first few hours. As the bulb ages, the color temperature reaches its
> nominal value of around 5600 K or 6000 K. With age, the arc length becomes
> larger as more of the electrodes burn away. This requires greater voltage to
> sustain the arc, and as voltage increases, color temperature decreases
> proportionately at a rate of approximately 0.5–1 kelvin for every hour
> burnt. For this reason, and other safety reasons, HMI bulbs are not
> recommended to be used past half their lifetime._

Oh.. Then again, burn-in is something all lamps suffer from, right?

[0] [https://en.wikipedia.org/wiki/Hydrargyrum_medium-
arc_iodide_...](https://en.wikipedia.org/wiki/Hydrargyrum_medium-
arc_iodide_lamp)

------
toomanybeersies
Interesting that they're in Northern California and get Seasonal Affective
Disorder.

I live at a similar latitude (except in the Southern Hemisphere) and have
never considered that it would be a thing outside of essentially polar
latitudes.

Over the past couple of winters (I moved further south a few years back) I've
had some atrocious winters in terms of mental space. Maybe this is something I
should look into.

~~~
Symbiote
[http://www.ncbi.nlm.nih.gov/pubmed/20170049](http://www.ncbi.nlm.nih.gov/pubmed/20170049)

Seems to conclude latitude doesn't make any difference, which is surprising.
But there are other papers with the opposite conclusion.

------
kristiandupont
I don't see any info about the spectrum produced by the bulbs he recommends.
Color temperature is one thing, but that's equivalent to describing a chord
with just the root key. I suspect that a spectrum as close to the sun as
possible (including UV and IR) is better.

~~~
dietrichepp
Any particular reason that you suspect that UV and IR are important, or is
this just pure speculation?

~~~
kristiandupont
No, that's just speculation.

------
atemerev
Occasionally (3-5 times per winter) I go to the nearest tanning bed room in
the nearby gym, choosing the bed with the least UV and the most brightness.

Yeah, I know, tanning beds are imported directly from Hell to give us skin
cancer and stuff. But a sunny day in LA or Barcelona summer will give you much
more UV than that. And it really helps with the aforementioned SAD.

~~~
jp555
Agreed about strategic tanning bed/booth use in winter. I don't understand the
worry when you can precisely dose the minimum light you need vs. A random
amount of much more ionizing sunlight.

------
mapt
It is perfectly within our reach to simulate a bright daylight sky with the
sun behind clouds - around 5k-10k lux - it just requires a fairly large
wattage of lighting in a number of indirect fixtures. White metal halide,
LEDs, and fluorescents all have efficiencies in the 50-100lumen/watt range,
that just means you need to apply around 100 watts per square meter of matte
white ceiling you're trying to illuminate. I like the idea of supplementing
the white lighting with colored (eg: red, red-orange, green) LEDs, which can
be throttled to achieve a particular color temperature.

Ideally your ceiling would be very high for this setup to give space for the
light to diffuse from hanging ceiling reflectors, which is unfortunately not
the case for most homes. For realistic homes, there is a style of floor lamp
termed 'torchiere' that may work, though for best results you're going to want
to find one with a large, fully reflective shroud - lights this bright are
pretty harsh if they're not diffused well.

Set up something like this on an automatic timer to simulate the sky, and I
suspect a lot of our sleep issues would go away fairly quickly.

~~~
wpietri
> Set up something like this on an automatic timer to simulate the sky, and I
> suspect a lot of our sleep issues would go away fairly quickly.

I had a similar hypothesis, so I built something like what you describe:

[https://github.com/wpietri/sunrise](https://github.com/wpietri/sunrise)

Currently I'm at only 4000 lumens or so in my main space, and I'd like it
brighter. But my sleep is definitely better. I attribute it not so much to the
daytime light, but to the way my apartment gradually gets dimmer and redder in
the evenings.

I had set out to make something like a SAD lamp for my whole apartment. But as
a side effect, I also basically made f.lux for my apartment, and I really like
it. When evening comes, I generally have to fight to stay awake rather than
fighting to go to sleep.

------
hngiszmo
As a tech fan, an on-off switch is too simple. I want to be able to adjust the
brightness and "color" like the volume of my stereo. I never put my stereo to
100% because we figured out long ago how to do affordable loud speakers that
are uncomfortably loud. Why haven't we figured out how to do affordable lights
that can be tuned to uncomfortably bright? I want Caribbean beach bright as my
100%, with an "equalizer", to tune the heat/reading comfort/UV/color to my
liking.

To me it feels like any advance in light bulbs is only on the lumen/watt
scale. How long until we have a one million lumen broad spectrum LED
configuration that doesn't cost a fortune?

------
shin_lao
I found the best to feel better during winter is to supplement my diet with D
vitamins.

~~~
Hugie
How much Vitamin D did you take? Did you measure/calc the amount per kg?

~~~
willsher
From research around the Internet, D3 is generally seen as safe
([http://www.mayoclinic.org/drugs-
supplements/vitamin-d/safety...](http://www.mayoclinic.org/drugs-
supplements/vitamin-d/safety/hrb-20060400) is pretty typical on the safety
information) Personally I take a D3 supplement of 2000IU/day during the dark
months (along with some other supplements due to a mostly vegan diet, some of
which contain low D2/D3 amounts, so my actual supplemented intake is around
2400 IU).

------
toomim
All you need is the 460 nanometer wavelength of light. That's what your eye's
daylight detectors are most sensitive to. Halogen lights don't have that
frequency, which is why they didn't work for you.

Furthermore, you don't need this light all day. Just in the morning and
evening.

You can get 460 nanometer LED lights from grow shops online for around $50,
and put it close to your face for 15 minutes in the morning and evening. It'll
reset your rhythm, cure your sad, and that's all you need.

~~~
Sammi
Finally someone mentions this. Wikipedia has all the imformation on this:
[https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...](https://en.wikipedia.org/wiki/Intrinsically_photosensitive_retinal_ganglion_cells)

It's because we have special photosensitive cells in the sides of our eyes
that only see blue light. They're not part of the vision, they only regulate
the circadian rhythm. So all this talk of white light is uninformed. You only
need blue light.

------
dolguldur
If you don't mind the process of finding something (or waiting for something
to come up) on eBay too much, I recommend looking for used photo/film
equipment out there. I cheaply sourced two photo/film lamps on eBay. One is a
500W LED lamp and somewhat blueish, the other is a 330W fluorescent, but of
very high quality, it's a very convincing daylight tone (not at all greenish).
Especially the latter makes for a very nice room light. Both were barely used,
yet substantially cheaper than new. The advantage is that you can easily
change their angle on one or two axes. I originally bought them for
photography and then started liking them as regular room lights, only to later
even realize that I basically got myself SAD lamps.

~~~
DenisM
Can you give some links of model #s? I've been thinking of this for a while,
but never knew where to start. Thanks!

~~~
dolguldur
No, sorry, unfortunately I can't. Bought mine on eBay.de a few years ago. Now
on eBay.com the auction format seems to be hardly used anymore for things like
that. Hmm. Many direct imports though. Maybe my suggestion is outdated.

------
zeristor
I thought that a large part of the positive response was due specifically to
light in the blue part of the spectrum. Hence blue LED devices, ironically
blue light should help you if you're feeling blue. I used a light meter app on
my iPhone to measure the light outside in London on a sunny winter's noon, and
that came in at 25 Mlux; suitable for an operating theatre apparently.

~~~
Sammi
Yes. Because of this:
[https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...](https://en.wikipedia.org/wiki/Intrinsically_photosensitive_retinal_ganglion_cells)

------
dfc
I have two questions:

1\. How hard is it to do work on your computer with that much light shining
directly behind your monitor?

2\. From the amazon bulb description:

"Remove The Electronic Ballast, Capacitor,Ignitor In The Fixture"

What does that mean? Is it a poorly written instruction to do some obvious? Or
is it a strange after market modification?

~~~
jloughry
The ballast, capacitor, and igniter in the Amazon description refers to using
the LED lamp to replace a sodium vapour bulb, usually in a large, outdoor
lighting fixture, like a street lamp. The LED doesn't need the same support
electronics that are required to warm up, start, and control sodium vapour
lamps, which have a negative resistance once they get going, and thus will
burn out quickly without a ballast in the circuit.

The LED lamp has just as much (or more!) support circuitry, but it's built-in;
note the comment in one of the reviews that it takes about four seconds to
light up once power is applied.

------
hga
I address this by sticking this light
[http://www.amazon.com/gp/product/B002WTCHLC](http://www.amazon.com/gp/product/B002WTCHLC)
9 inches from my face instead of the prescribed 12 inches for 10,000 lumens,
and use it for 40 instead of the normal 30 minutes/day. Inconvenient, but has
made _major_ improvements from the (still useful but not as much) Phillips
6x10 array of blue LEDs I started with at 12 inches 3*30 minutes a day. Also
helps me wake up in the morning ^_^.

That said, this seems to be right to me, but I could well believe there are
people who need 30,000 lumens and therefore have to get more creative.

------
applecore
You seem convinced your brain "slows down" after the equinox due to (the lack
of) bright light, but it's probably just the placebo effect. Has anyone ever
convincingly measured the effect of bright light therapy on mood and
intelligence?

~~~
wpietri
Would you care to show the math on your "probably" here? Because I suspect
it's not an actual mathematical estimate, but a way of puffing up your
personal guess. Which is a weird thing to guess about given that this person
has orders of magnitude more data about their experience than you do.

~~~
applecore
Sure thing! A meta-analysis of placebo-controlled trials found that when
disorders are amenable to placebos, the placebo effect is robust and
approaches the treatment effect[1]. For psychological disorders, particularly
depression, it's been shown that placebos are nearly as effective as active
medications[2].

[1]:
[http://www.annualreviews.org/doi/abs/10.1146/annurev.psych.5...](http://www.annualreviews.org/doi/abs/10.1146/annurev.psych.59.113006.095941)

[2]:
[http://onlinelibrary.wiley.com/doi/10.1002/jclp.20129/full](http://onlinelibrary.wiley.com/doi/10.1002/jclp.20129/full)

~~~
wpietri
You're asserting a nocebo effect, not a placebo effect, so I don't believe
your links are relevant. Further, this person is talking about a perceived
correlation between an experience and a natural change, not an intervention,
which means it may not even be a nocebo effect, but a different category of
issue altogether. Given that, I again suggest you cannot actually demonstrate
any math on your claim of probability. Again, I think you're dressing up your
feelings in sciencey talk.

Further, your request is nearly tautological. The way that one gets to a big,
statistically robust test of a hypothesis is via small stepping stones. E.g.,
this sort of self-experimentation. If you scoff at everybody doing something
small and say, "you're probably wrong because there's no big evidence", you
decrease the chances of getting the sort of proof that you claim to want.

I don't think there's anything wrong with saying, "personally, I'd like to see
convincing measures of the effect of bright light therapy on mood and
intelligence before I adopt this." But that's frustratingly different than
your apparent attitude that in 2 minutes of thought you know more about this
guy's experience than he does.

------
dalys
Wouldn't it be better to set f.lux to a latitude of 0 degrees and a longitude
of 0 degrees?

I live at 59°N 18°E so the opposite hemisphere would mean I currently would
have daylight between 02:29 and 19:31. While 0, 0 gives you roughly 06:00 -
18:00.

------
Andys
I work from home in an area that gets high amounts of fog, and I frequently go
days without seeing the sun. I can confirm that I seemed to need about 10k
lumens before making an noticeable change in mood.

I used three (1 warm, 2 cold) relatively inexpensive 36W LED bulbs from ebay
locally -
[http://www.ebay.com.au/itm/121704759594](http://www.ebay.com.au/itm/121704759594)

(Note they are LARGE and require a free-standing light fixture without any
type of lampshade)

------
rsync
I searched the authors posting for the word "exercise" and found it appears
zero times.

I'm all about minute optimizations, but not until you've exhausted the big,
basic ones.

Your (insert issue here) is not interesting at all unless it manifests itself
_in the presence of_ regular walking, weekly resistance training and a decent
cardio routine.[1]

Do all of those things and your (issue) is still extant ? Well, now we've got
something interesting to talk about...

[1] Also known as, basic, functional human output.

~~~
DenisM
Exactly. All of that, plus basic sleep hygiene. If you are complaining about
sleep and energy levels, and yet you haven't been following sleep hygiene
rules religiously for at least 6 weeks, then you're just fooling yourself.

These are easy to implement, they are proven medically, and they have tons of
other benefits for heart health etc.

~~~
nitrogen
It's easy to say things are "easy to implement" when you don't have SAD.

How are you supposed to exercise if you're already suffering from SAD? How
much of the perceived benefit from walking comes from sunlight exposure? What
about climes where there are extended overcast periods with no direct sunlight
for weeks at a time?

Any claim of "you can't do X until you did Y first" is of little value to
people who have adequate motivation or resources to do X but not to do Y.
Maybe doing X will make it easier to do Y later.

In fact, this is the exact approach I took; one of my motivations for starting
an automation startup years ago was better lighting for myself, and that
better lighting later made it easier to exercise more, start swimming
regularly, etc.

~~~
DenisM
Sleep hygiene does not include exercise, but has half-dozen smaller things. If
you don't have enough motivation for it, you need to see a doctor asap.

Creating a startup to treat a mood disorder is a very roundabout way of doing
things.

~~~
nitrogen
I was replying on a phone (and am doing so again now), and regrettably left
out a few details. First, I was replying both to your comment and to the
parent comment. Second, I have not been diagnosed with SAD, but I do have a
delayed/non-24h sleep cycle that is exacerbated by the short, cloudy,
pollution-heavy winter days where I live.

My main objection to rsync's comment was the flippant dismissal of people with
actually diagnosed depression ("not interesting" were the exact words).

In response to your present comment, I would say that people who find
themselves trying to invent solutions to their problems have likely already
found the medical establisment to be less than helpful.

------
jrockway
Isn't staring into your computer screen all the light you need? Everyone (even
Apple now) says that the light screws up your sleep cycle. Wouldn't it help
with SAD?

~~~
jordanthoms
It's (probably) enough light to disrupt melatonin production in the evenings,
but that doesn't imply that it's enough light to get you to produce Vitamin D
etc and help with SAD during the day. Computer screens don't produce much
light even compared to a normal bulb.

~~~
jrockway
Good point. I forgot about Vitamin D.

But isn't that produced through exposure to UV, which LEDs don't emit?

------
keithpeter
I live at 52.5 degrees North. Cosine to the power 4 being what it is, my
neighbours and I could be experiencing significantly lower levels of daylight
_intensity_ in all seasons than people who live at lower latitudes. In the
summer, we will see similar or slightly more daylight integrated over the
duration of the day because of the longer days.

The OA does not specify the latitude at which he(? assuming the OA is the site
owner's work) is living.

~~~
alkonaut
Try SAD at 64 North. No picnic. I'd really like to try s light but don't think
I'd have the patience to sit in front of one long enough. If it could be made
bright enough that you could have it overhead and work at the same time that
would be brilliant.

~~~
marvin
I have one of these on my desk, right next to the monitor. Working in front of
it for 30-60 minutes a day really helps. Live at 60.5 degrees north. Also take
vitamin suppliments and exercise more in winter; it's hard to tell what causes
the improvement. With a lamp like this, you don't have to do anything outside
of your routine to get more light. You can keep it 20 centimeters (~1 foot)
from your eyes, so reduced irradiance due to distance (as this article points
out) is not a problem.

[http://www.usa.philips.com/c-p/HF3318_60/energylight](http://www.usa.philips.com/c-p/HF3318_60/energylight)

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lugus35
Of interest

[https://news.ycombinator.com/item?id=10802144](https://news.ycombinator.com/item?id=10802144)

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upofadown
There is some thought that the normal yellowing of the lens as people get
older makes them less sensitive to the effect of blue light. If so, then older
people need more light to get the same circadian effect as younger people. It
would be interesting to know how old the writer is.

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bash-j
I found you can get cheap <$100 LED 10k+ lumen flood lights targeted at the
4WD market off eBay. You just then need the appropriate power supply, again
cheap ~$20.

edit: colour for most seem to be 6500k too

~~~
bash-j
Here's an example as a 30k lumen light bar for only $142

[http://www.ebay.com/itm/52INCH-300W-LED-LIGHT-BAR-
Mounting-B...](http://www.ebay.com/itm/52INCH-300W-LED-LIGHT-BAR-Mounting-
Bracket-For-Jeep-JK-Wrangler-Wiring-Kit-US-/281684824117)

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insickness
He doesn't mention an important variable here: time. The less light you have,
the more time you need to achieve the desired effect. I leave my lights on all
day and they work to reduce my SAD.

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peter303
Colorado pot grower suppliers market LED grow lights that simulate sunlight.
Conventional grow lighting is one the largest energy hogs in Colorado. LED
alternatives consumea sixth of the energy.

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lelf
> _There’s clinical evidence that ramping up the brightness gradually before
> you wake up (“dawn simulation”) is highly effective._

Can someone recommend a ready-made solution?

~~~
nmcfarl
I use a Phillips hue system to do this. Not for SAD reasons - just because I
found it much less jarring to wake up with the sun when I could do that, than
with an alarm clock. Since waking up at set time became necessary I tried this
out and it works fantastically. Plus the hue system is very versatile and
programmable with many other tricks. Not exactly cheap though.

~~~
wpietri
I second the Hue recommendation. They're a solid product. They aren't as good
at rendering arbitrary color, but that's because they optimized for excellent
whites.

Their API is also really good: clear, well-documented, REST-y. I wrote my own
software to simulate a day/night cycle in my house, and I'm very happy with
it. It's a much easier way to wake up, and having the gradual dimming in the
evening makes it easier to go to bed on time.

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polynomial
How did I never notice that Seasonal Affective Disorder is "S.A.D."?

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lumens
I've been saying this for years.

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coderdude
Feeling bad because it's winter? Yee-ikes. Plant problems. I can't believe
it's actually called SAD. Luckily summer will be here again and we can all be
STOKED.

