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Full Spectrum Lighting - Is it any better?

Posted by Cliff on from the as-long-as-it-works-with-a-prism dept.

lennon asms: "Lighting in my apartment sucks. I am giving some thought to full-spectrum lighting fixtures, like the the Vita-lite. Some places say it's not any better than regular lighting, others say it's just great. What do you think?" I find the quality of lighting in my work environment to be very important. Would lights such as these be better than your standard soft-white or flourescent bulbs?

10 of 58 comments (clear)

  1. There's only one person who can answer that.... by joto · · Score: 2, Informative
    ...And that is you! It is fortunately not uncommon that different people have different preferences. That's why asking others will often result in different people giving you different answers.

    Whether you prefer "full spectrum lighting", "blacklight", normal lightbulbs, "warm" lightbulbs, darkness, daylight through the window, stroboscope, or any other form of lighting is up to you.

    If you think "full spectrum lighting" will make you happy, try it, and see what you think. End of story.

  2. Great, but.... by cpuwizard · · Score: 3, Informative

    Having put them in my office a few years ago, I must say I love them. The only problem is that you must do it to EVERY room. Otherwise, other rooms become obviously yellow (or pink or green if you have fluorescent).

  3. That may not be a coincidence.... by coyote-san · · Score: 5, Informative

    Hmm... on the one hand you have large rooms lit by the standard el cheapo fluorescent tubes. On the other hand you have a bunch of educated people prefering darkness to bad illumination.

    Think it's just a coincidence?

    Now toss in the fact that most monitor's (and all TVs) are "hot" - they're far more blue than they should be since it's a cheap way for the manufacturer to make them look "bright." (That's also why rooms with TVs look blue from outside.) Better monitors allow you to adjust the "color temperature", but most people don't know about this control or find a cooler temperature "dull."

    This means that people who work in front of a screen are getting hit with excess blue, and the overhead fluorescent lights also have excess blue.

    Still think it's just a coincidence?

    Personally, I wouldn't mind seeing OSHA mandates that overhead lights be full-spectrum and monitors be adjustable to the natural temperature (6500K?). It takes a few days to get used to it, but it's a lot more comfortable.

    --
    For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
    1. Re:That may not be a coincidence.... by RobbieW · · Score: 3, Informative

      I come from a commercial printing background. In that industry lighting is a BIG DEAL

      Natural Sunlight on an average clear day is around 6500K. The industry standardized on 5000K based on some french research. It's been a while and I don't remember the details of the CIE study that produced the information. Mostly it was about the standard observer. Most of your calibrated light tables and viewing boxes are 5000K.

      We switched over to 5000K flourescent tubes in our office a few years ago to make it easier to judge color proofs and the difference was amazing. These tubes have illuminants that provide 91% of the full spectrum. They're about $5/per tube, but they last longer than your standard el-cheapo brand.

      If you are a light-sensitive person give these a try, you'll probably be pleasantly surprised and it may improve your mood, particularly during the winter.

      YMMV and unfortunately I don't remember the exact details of the bulbs. I believe they are functionally equivalent to the other full-spectrum bulbs available but we purchased them through our graphic arts supplier so I know they could be gotten cheaper elsewhere.

      I went back into programming and now all my illumination comes from halogen desk lamps.

  4. Full spectrum lighting by gully42 · · Score: 2, Informative

    You will find that full spectum does provide a nice psychologial effect, especially if you are in and out of the sun alot. your eyes gradually adapt to lousy light (like older fluorescents), but the difference can be rather striking. Nothing beats real sunlight though. Full spectrum lighting is essential in locations where you must carry out color-sensitive tasks (retail, hospitals, electronics assembly). But it is also nice in home environments, good for skin tones and fabrics. I suggest newer (Tri-phosphor) fluoresecnt lights, they provide a very broad spectrum and efficient output.

    --
    fortune: You die cold and alone
  5. Re:Works for me by maetenloch · · Score: 3, Informative

    Now that I'm back at my office, I checked and actually I'm using GE Chroma 50 (AKA GE Sunshine) bulbs (CRI 91, 5000 Deg.). You can get more information at the GE FAQ. Also there's a nice comparison of different light sources here.

  6. light mood by Anonymous Coward · · Score: 1, Informative

    The guy who wrote the book (Winter Blues) on
    how light affects mood is Dr. Norman Rosenthal
    (http://www.normanrosenthal.com)

  7. Full Spectrum or ? by gordguide · · Score: 2, Informative

    First of all, I want to go on record as saying I have tested/tried FS lighting and I am supportive. For me, it worked very well.

    Fleuroescent lights, by their nature, are mixtures of gases which approximate "real" light. Generally you could think of it as similar to theatre light; add the 3 colors and you get white.
    However, FL gases are not a smooth dim-to-bright-to-dim spectrum type of light. There are always areas of the spectrum that are missing, and it is the careful (or haphazard) choice of gas that determines how close it can get to white light.
    Incandescents are continuous spectrum, with typically blue missing (hence the yellow cast in photos). But, and this is a big but; they are continuous from the "first" color to the last color they can display. FL lights will have gaps (some of the colors of the rainbow are missing entirely).
    Thus, FL "full spectrum" lights have more attention paid to haveing all colors represented, but to do it like sunlight, candlelight or incandescent light is pretty much impossible. There will still be areas of the visible spectrum with little or no output. That's why they cost more than "regular" FL's (some of the gases cost more) but they still may be unsatisfactory to sensitive individuals or for critical color matching.

    Incandescent Full Spectrum are available; the drawback is cost and overall life. In other words, you probably won't see them in the IT department of MegaCorp. FL Full Spectrum are then still a compromise; it is possible for some individuals to get headaches from them (as they can from all FL lighting).

    Having said all that, Full Spectrum are usually better than regular "el cheapo" FLs if that't the kind of light you're stuck with. Just as with regular FLs, brand and product differences exist, so some experimentation may be necessary.

  8. What were you smoking? by dhartshorn · · Score: 4, Informative

    when you wrote that? Have you ever looked at a spectral analysis of a fluorescent light? The ones I'm looking at (Illuminating Engineering Society Lighting handbook, Reference Volume) show a continuous distribution with four spikes that are present in all bulbs classified (Cool White, Warm White, White, Deluxe Cool White, Deluxe Warm White, and Daylight).

    Your theory of gas mixtures affecting color is also incorrect. Fluorescent lights are the product of an electrical discharge in a low pressure mercury vapor. Some trace gases are added to improve startup, but not color. Color is determined by the phosphor coating on the glass, in exactly the same manner color is determined in CRTs. Change phospors, change colors.

    Observing the spectra of the different classes of fluorescent bulbs shows that Cool White (most typical) differs from Daylight by a reduction in the red (slight) and yellow (significant)and an increase in the green (slight) and blue (significant). Cool White has a yellow component peak that is approximately double the value of the peak that straddles blue and green. In the Daylight bulb, the peaks are relatively the same. The two of the four spikes (yellow, green, blue, and indigo) are also affected, with yellow reduced and indigo boosted.

    Incandescent (tungsten filament) lamps are stronger radiators in red than blue, following a somewhat straight line that gives us a red luminace that is approximately 4 to 5 times greater than blue. Yellow comes in at about 3x blue.

    Sunlight has a strong peak in the blue-green and decays to about half power in the red. Continuous, but not uniform. And it clearly demonstrates why Daylight bulbs boost the blue component (while still leaving at least 1.5X the "natural" yellow component).

    (This clearly shows that six pictures and some graphs are worth a couple hundred words.)

    1. Re:What were you smoking? by gordguide · · Score: 2, Informative

      "... Full-Spectrum Fluorescent Lamps in Context
      There are two broad classes of electric light sources available for interior lighting; incandescent light sources and discharge light sources. Incandescent light sources produce light by heating a filament, the spectrum of the light being determined by the temperature of the filament.
      Discharge light sources produce light by passing an electric current through an ionized gas; the spectrum of the light being determined by the gas used, the gas pressure, the other elements in the discharge and the presence or absence of a phosphor coating. Full-spectrum fluorescent lamps are low pressure, mercury discharge lamps with a phosphor coating. The discharge in the mercury atmosphere produces mainly ultra-violet radiation. This ultra-violet radiation is largely absorbed by the phosphor coating lining the walls of the discharge tube and reradiated as light. Incandescent lamps have a continuous spectrum in the visible region, dominated by the long wavelengths (see Figure 1).
      Discharge lamps typically have a spectrum consisting of strong single wavelengths amongst a continuous background ... "

      From:
      Is Full-Spectrum Lighting Special?
      Peter R. Boyce, Ph.D.
      Lighting Research Center
      Rensselaer Polytechnic Institute
      Troy, NY 12180-3590 U.S.A.

      Okay, I stand corrected. After all, when you look at graphs of FL lighting, there is a "continuous spectrum" of light, typically 100 times less bright than the spikes. So, technically, you're right. In layman's terms, I stand by my assertation that the light emitted is dominated by a few bands of color separated by nearly no light output in other colors.
      The type of gas used can and does affect the light specrum. Phosphor coatings are not present on all types of FL tubes; it depends (again) on the desired lighing qualities, including spectrum.

      100W Incandescent: less than 10 mw/nm at approx 450nm, rising steadily to 50mw/nm at 800nm.

      65W FL: Less than 10mw/nm at: 300-400 nm but with a narrow spike of 35mw/nm at about 370nm; approx 25mw/nm at 400-500 nm but with narrow spikes of 75 and 200 at approx 410 and 430nm; medium width spike at approx 570nm of between 50 and 150 mw/mn.

      90 W Low Pressure Sodium (isn't that a different gas?): virtually no output (no measurable output on the graph, could be some at 10mw/nm or less) except for a 3300mw/nm spike at about 590 nm.

      400W Metal Halide Mercury: Spikes of 1000 mw/nm at approx 300, 350 and 400nm; spikes of 1500 mw/nm at approx 550 + 580; one spike at about 620nm of about 800mw/nm. Output at all other wavelengths less than 30mw/nm, some not showing on the graph at all (could be zero?).

      Now, a graph is a funny thing to base your info on (easily fudged and "prettied up"); these are from a submitted paper. However, feel free to read the whole thing (and more) at:
      http://www.nrc.ca/irc/fulltext/ir659/contents.ht ml

      The quoted paper is available PDF on that page, as are others.