>>tooman+lb1
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.

>>windsu+mc1
I posted a little further investigation at http://meaningness.com/metablog/sad-light-lumens/comments#co...

> 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/

>>kristi+Vb1
In the article she talks about CRI ( https://en.wikipedia.org/wiki/Color_rendering_index ) which is similar

>>ivank+(OP)
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/ 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.

>>dietri+cc1
Thanks for pointing that out, and that is what I get for relying on memory.

I did a bit of googling and found this...

http://www.ccfg.org.uk/conferences/downloads/P_Burgess.pdf

... which looks relevant and interesting.

>>ivank+(OP)
A recent Cochrane review found very little high quality evidence in either direction:

http://www.cochrane.org/CD011269/DEPRESSN_light-therapy-prev...

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

>>Hugie+ad1
From research around the Internet, D3 is generally seen as safe (http://www.mayoclinic.org/drugs-supplements/vitamin-d/safety... 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).

>>ivank+(OP)
Of interest

https://news.ycombinator.com/item?id=10802144

>>alkona+Nb1
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

>>julian+Zb1
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_...

>>adanto+ye1
They're being sold in the UK here for GBP £70 (probably excluding VAT at 20%).

http://www.limelitelighting.co.uk/product.asp?code=PulsarChr...

>>radiow+hf1
That seems too good to be true. It's difficult to find prices for this product, but a couple of German stores I found charge at least 10x the price:

http://www.arax.de/architektur/preislisten/10_pulsar_leds.pd... (>2500 EUR)

http://www.lightpower.de/fileadmin/user_upload/lightpower/Ho... (1000 EUR, used)

>>lelf+gg1
I have this: http://www.amazon.de/Philips-HF3520-01-Sonnenaufgangfunktion...

Not sure if it helps, but it is nicer to wake up to compared to using a regular alarm clock.

>>mapt+8i1
I don't believe you need high ceilings; you can diffuse light just as well over short distances with metamaterials. Look at http://coelux.com/, for example. Ideally, you'd want one of those, brighter, covering your whole ceiling.

>>sambe+Ad1
My contribution to anecdata is this:

Parents bought me a 180W fluorescent (therefore 10800 to 18000 Lumens according to https://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2 ) anti-SAD lamp.

Stupidly, I used it as an evening lamp instead of anti-SAD. I had serious troubles getting to sleep for an entire year. Typically took 1-3 hours. Blamed coffee, stress, etc. Got blackout curtains, earplugs, cooled room temp, reduced coffee, etc. When I made the connection b/t falling asleep and the anti-SAD lamp, I stopped using it altogether and almost instantly started falling asleep rapidly.

So I conclude my 10k-18k lumen lamp stimulated my awake cycle by about 1-3 hours. My suggestion therefore is: use the lamp at either end of the day in winter: just before sunrise and just after sunset. And certainly to shut it off 3 hours before bedtime. In practice this is tricky because the "unwanted dark hours" are 4:30pm to 7:30pm which is: at work, my commute home and first hour at home. So I need three lights, including one in the car?!

>>ivank+(OP)
I address this by sticking this light 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.

>>mapt+8i1
> 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

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.

>>wpietr+0o1
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...

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

>>buro9+od1
LED street light units are becoming reasonably priced.[1]

[1] http://www.amazon.com/Yescom-98-Watt-Wired-Street-Garden/dp/...

>>toomim+Ey1
> You can get 460 nanometer LED lights from grow shops online

What about these: http://www.ebay.com/bhp/460nm-led ?

>>ivank+(OP)
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

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

>>jschwa+Px1
> 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

>>bash-j+Eb2
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...

>>toomim+Ey1
Finally someone mentions this. Wikipedia has all the imformation on this: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...

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.

>>zerist+Hd1
Yes. Because of this: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...

>>polyno+9L1
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...

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