Debunking Full-Spectrum Lighting Claims

GreenSwirl writes "Full-spectrum light sources often are claimed to promote health, mood and productivity in schools and offices. The Lighting Research Center at Rensselaer Polytechnic Institute in Troy, New York, has published an independent report evaluating full-spectrum light sources. Practically all health claims are debunked and many products are shown to have a less-than-full spectrum. The report was produced as part of the National Lighting Product Information Program, an objective third-party funded by government and utilities."

Bah, it just looks nicer!

[RevAaron]

I can't say that I have even heard about any supposed health benefits derived from full-spectrum lighting, or any other purported or proved claims.

However, we use full-spectrum bulbs a few places around the house, anywhere we don't have flourescent bulbs. Why? It just looks nicer! My SO and I can't stand the yellowness of regular bulbs, and we prever the whiter light of the full-spectrum guys, especially for reading and similar activities.

Re:Bah, it just looks nicer!

[moof1138]

Color temperature and 'full spectrum' are not really the same thing. A lot of cheap fluorescents have a low color temp around 2700 that looks yellowish, but you can buy fluorescents that have a higher color temp. Depending on what you like 3500-4100 bulbs are out there that will put out light that looks 'whiter', though if you go high you get a bluish look about 4500.

Re:Bah, it just looks nicer!

[RevAaron]

I guess should've have mentioned the fluorescents, it seems to have confused you (and probably other folks). The full-spectrum bulbs we have are not fluorescent.

Re:Bah, it just looks nicer!

[moof1138]

Whether you buy a nice higher color temp incandescent bulb that is labeled 'full spectrum', or you get the cheapest incandescent bulb you can find, you will find that they are both full spectrum. The issue that causes typical fluorescents to only emit light in certain color bands does not affect incandescents. The bulbs labeled 'full spectrum' incandescents are just incandescents with a coating to give them a higher color temp, which just helps to confuse the meaning of the term. I do agree that higher color temp light is nicer.

it's because of your flourescent bulbs

[SuperBanana]

However, we use full-spectrum bulbs a few places around the house, anywhere we don't have flourescent bulbs. Why? It just looks nicer! My SO and I can't stand the yellowness of regular bulbs, and we prever the whiter light of the full-spectrum guys, especially for reading and similar activities.

Siiigh. Okay, let me put my theatrical lighting designer hat on.

Your brain has a sort of biological "automatic white balance". It gets 'used to' different lighting so you 'see' the same colors.

This is both exploited by, and an annoyance for, lighting designers- if you have a very 'cool' scene, the next that follows will appear much warmer than it would to someone, say, walking in off the street.

The problem here is that you're used to the flourescent bulbs(which have a very high color temperature, ie, they're "cool" light- yes, it's odd). When you walk into a room with a regular incandescent bulb, your brain is 'calibrated' for the floursecent bulb and the light seems very warm. In the theater industry, there are specifically designed correction 'gels'(filters that look like they're plastic, but they're not- plastic would melt) for flourescent, HID and incandescent bulbs to make them 'look' like other light sources, or at least get them to a common baseline to then further color them with another gel.

This effect works in other ways- headlights look yellowish during the day but bright white at night. People driving cars with HID lights see 'normal' headlights as looking very yellowy; we see the HID lights as looking very blue.

If you want to see the effect yourself, find some lightly colored plastic, preferably light blue or light orange. Hold it over one eye, with the other closed, and after a minute or two, remove the plastic and note how the room looks different lighting-wise...

Re:it's because of your flourescent bulbs

[mu_wtfo]

Actually, gels are totally plastic. And they *do* melt, but only if you use 'em wrong. The leading US manufacturer of color media used in the entertainment industry (film uses 'em as well) is Rosco Laboratories [rosco.com]. Most of their line is now made from polycarbonate, but some is still polyester. The polyester stuff tends to be the lighter colors, since they absorb less IR.
Rosco has a pretty good technical run-down of the manufacturing process - http://www.rosco-ca.com/products/filters/filters-r oscolux.html#S [rosco-ca.com]

Re:it's because of your flourescent bulbs

[BobTheLawyer]

"Basically, no matter what you add to a source (whether it be a cut of gel or that blue coating on those "Full Spectrum" lamps), all you're doing is *removing* wavelengths of light."

true when it comes to filters, but not true generally. Coatings can be added (e.g. of phosphor) which absorb light of one frequency and emit light of another. Most white LEDs, for example, are blue LEDs with a phosphor coating.

Re:it's because of your flourescent bulbs

[mu_wtfo]

Actually, in the case of phosphors, the coating *is* the source. UV (in the case of fluorescents and some LEDs) or blue (like you said) strikes the phosphors, and stimulates them to emit their own light.

Re:Bah, it just looks nicer!

[calethix]

I put some in my office (which happens to be in the basement, i.e. no windows/natural light) because I thought they looked nicer. I've noticed since then that I haven't had near the problems I used to have with getting sleeping and yawning in the afternoon.

It wasn't exactly a controlled experiment and I may have changed something else that reduced my sleepiness but I've heard other people claim the same thing. Regardless of that, if I prefer the lighting better, then that's enough of a benefit for me.

Debunking?

[Henry V .009]

Since when does "We don't know" count as a debunking?

Full-spectrum light sources and health. Full-spectrum light sources will not provide better health than most other electric light sources. Recent research has shown that human daily activities are strongly influenced by the solar light/dark cycle. The most notable of these daily, or circadian, cycles is the sleep/wake cycle; but other activities including mental awareness, mood, and perhaps even the effectiveness of the immune system go through regular daily patterns. Light is the most important environmental stimulus for regulating these circadian cycles and synchronizing them to the solar day. Short wavelength (blue) light is particularly effective at regulating the circadian system; long wavelength (red) light is apparently inconsequential to the circadian system. Thus, to maximize efficiency in affecting the circadian system, a light source should not mimic a full spectrum, but instead should maximize only short wavelengths. Even if a full-spectrum light source includes short wavelength light in its spectrum, it will not necessarily ensure proper circadian regulation because, in addition, the proper intensity, timing and duration of the light exposure are all equally important for satisfactory circadian regulation (Rea et. al, 2002).

I would actually be surprised if there were no benefits at all. We already know that sunlight is well correlated to depression levels in a population. And depression is quite well correlated to any number of health factors.

Re:Debunking?

[barakn]

We already know that sunlight is well correlated to depression levels in a population.

Yeah, whenever I get any sunlight I get a sunburn, and that really depresses me.

But seriously, how about 'negatively correlated'?

Re:Debunking?

[Henry V .009]

Of course you a right, I should have been clearer. But then again, a negative correlation is just as much a correlation as a positive correlation is. Its opposite is a non-correlated event. Clearly we have a "positive" bias in our language that needs to be eliminated. I am preparing letters to the English Teachers of the world even now.

vitamin D

[Spetiam]

and we know for a fact that sunlight enable the body to produce vitamin D.

"Exposure to sunlight catalyzes the production of vitamin D in the skin. In low sunlight, the skin produces significantly less vitamin D." [goodshape.net]

Looks good in a fish tank...

[molo]

I use "full spectrum" lighting in fish tanks, because it looks good.. but who the heck would believe that full-spectrum light would have health benefits? (except maybe to plants)

-molo

I can see clearly now

[orthogonal]

I have full-spectrum lighting, dude!

I can see light in 256 * 256 * 256 colors from my monitor, and that's the only light here in my mom's basement.

MyDoritos, Ding-Dongs, and Mountain Dew look great in this light.

Why would I need anything more?

I mean, except, I hope my mom will clean up down here in the basement soon.

Re:I can see clearly now

[Alsee]

I can see light in 256 * 256 * 256 colors from my monitor...
MyDoritos, Ding-Dongs, and Mountain Dew look great in this light.

Yeah, but girlfriends look even better in 256 * 256 * 256 light! Gigs and gigs of girlfriends!

-

Re:I can see clearly now

[pweitz]

I have full-spectrum lighting, dude!

I can see light in 256 * 256 * 256 colors from my monitor, and that's the only light here in my mom's basement.

Actually this NYTimes.com article [nytimes.com] [reg-required] points out that most monitors only display a fraction of the NTSC color pallette.

Full Spectrum Lighting

[Peapod]

That's why I use nothing but x.Spots to light my apartment. Nothing like a 1000w robotic light to fill the room.

-Peapod

Re:Full Spectrum Lighting

[stienman]

I can see [beekley.com] why you might like "x-spots"...

Beekley X-SPOTS more flexible material contours to the breast under compression, making it more comfortable for the patient. X-SPOTS medical-grade, hypoallergenic adhesive is especially appreciated by older patients' sensitive skin. Each marker is latex-free, single-use and sanitary.

-Adam

Re:Full Spectrum Lighting

[mu_wtfo]

x.Spots [highend.com] are nice, but certainly not full-spectrum. They use a MSR 700-watt short arc lamp, so their spectrum is very heavily toward the blue (as with most arc lamps used in entertainment) and *very* spiky. They're also freaking *huge* units - took 4 of us to put 'em in their road cases after the DMB concert last year. If you're in the market for nice, cheap-ish wiggle lights, check out High End [highend.com]'s Studio Spot [highend.com] / Studio Color 250 [highend.com] range - small, and with most of the capabilities of their bigger siblings.
I'm rea

Effects may be just due to bright light

[nixman99]

Here in northern England, the winters get mighty dark. I've found that using a full spectrum light to illuminate a room definitely increases my energy level in the evening. But I've wondered if the effect occurs just because the light is so bright: if feels like it's still afternoon, so my body acts like it.

As a side note, the full spectrum light has the cool effect of giving the house a sort-of radioactive glow 8-)

Re:Effects may be just due to bright light

[Alsee]

the full spectrum light has the cool effect of giving the house a sort-of radioactive glow 8-)

Dude!
Your light is a bit TOO "full spectrum" if it reaches into the radioactive range!

-

Re:Effects may be just due to bright light

[s.fontinalis]

I believe there's this phenomena called a "pub" in Northern England that's supposed to increase energy. I highly recommend it with a pint of bitter.

Well, duh..

[Anonymous Coward]

I would expect "full-spectrum" lighting to include strong X-ray, ultra-violet and microwave radiation. Who'd have thought that would have a negative effect on one's health... :)

Pardon my ignorance

[WTFmonkey]

So, is "full-spectrum lighting" book-learnin talk for using white light bulbs instead of the yellow ones? Or is it entirely different than plain-old white-light incandescent bulbs?

Re:Pardon my ignorance

[moof1138]

Full spectrum refers to fluorescents. Most cheap fluorescents have light that spectrally has a few peaks on visible wavelengths, and minimal or no light on others, though the light sill looks white to the eye. Full spectrum fluorescents have a mix of phosphors in them so that light from across the spectrum is emitted by the bulb to some degree - though there are still some peaks and lows nothing is skipped altogether.

Re:Pardon my ignorance

[greenhide]

Actually, there are incandescent bulbs [fullspectr...utions.com] (i.e., normal screw-in bulbs with filaments) that purport to offer "Full Spectrum" lighting. I think the issue isn't whether they're fluorescent or not; it has to do with the wavelenghts of light given off.

Re:Pardon my ignorance

[moof1138]

That is kind of weird. The resaon that spectrum matters with fluorescents is that when you are hitting phosphors with electrons you get a very specific band of light that is emitted. That is why you need to mix up the phosphors used in the bulb to try to get an even looking white.

AFAIK, when you run a current through a filament in an incandescent bulb the spectrum emitted is continuous, so you are going to be getting the full spectrum by default with a standard incandescent.

From the page you referred t

Re:Pardon my ignorance

[moof1138]

I forgot to add that the color of a bulb, white vs. yellow is 'color temperature' and is not related to whether a bulb is full spectrum.

Superman

[Anonymous Coward]

Well... anyonw that knows anything about Superman knows that Red-star sunlight just isn't that good for you, and that yellow-star sunlight can give certain people super-powers...

I can tell you what they do do

[Kris_J]

They block cheap IR remotes. Took me a few days after I bought a FS light before I realised why my PSX remotes were acting as if broken.

Re:I can tell you what they do do

[Kris_J]

Yeah, except that no matter how noisy a bulb is, if it doesn't output in the IR end of the spectrum it doesn't block IT remotes.

No Way...

[inertia187]

No way, man. Full-Spectrum Lighting [blat.info] is totally bunk!