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We all want the best illumination with which to enjoy our epson prints! So here is is my mini-tome and collection of links. Part 3 of 3. ---- 10. UV Component of Full Spectrum Fluorescents: Brighteners, Fading & Health ----- The spectral output of solar illumination (at 5000K) is fairly flat throughout visible wavelengths, except that intensity starts to decline at the violet edge of human vision. The decline continues through near-UV (UVA) and Mid-UV (UVB) and reaches zero near 300 nanometers. Far-UV (UVC) is completely filtered by the ozone layer, and is absent from fluorescent lamps (except germicidal lamps). Some manufacturers insist that "true" full spectrum bulbs must mimic the UV output of solar illumination (missing UVC, appropriate levels of UVA and UVB). Others use a looser definition of "full spectrum" in that all (or nearly all) of the UV is filtered out by glass additives or coatings. For epson prints, some UV output enhances the performance of optical brighteners in the paper, which makes colors more vivid and text easier to read. The downside is the potential for increased fading. The epson list has had some discussion on the role of UV versus visible light in fading. For example, R. Moyer cited Wilhelm's discovery that red light fades (at least some types of) cyan dyes. Philips has an interesting page on fading... http://www.lighting.philips.com/nam/prodinfo/fluorescent/p5037_03.shtml Some manufacturers claim health benefits of UV output. This is a known fact for pet reptiles. Humans need UV for synthesis of the Vitamin D series; but that is available in enriched milk. Is Vitamin D the tip of the iceberg; are there unknown health benefits of UV? I suspect so. I do believe that some manufactures are prematurely overstating health benefits of UVA + UVB output (bordering on hype or even fraud). The downside is that UVB causes cancer and sunburn. Some dermatologists believe (given Vitamin D enriched milk) that there is no health benefit to UV at all, only risk. I think that is hysteria. Oxygen, copper, selenium, iron and many other nutrients are toxic at high doses but absolutely essential in appropriate dosages; I predict that future research will show that UVA and UVB will turn out to be the same. Is a full spectrum better for treating seasonal depression; or is it just a matter of intensity? Are full spectrum bulbs with UV better than those that filter out UV? Are full spectrum bulbs with flat and continuous spectra better than well balanced discontinuous triphosphor bulbs (or hybrid bulbs)? Some manufacturers claim benefits for full spectrum; most photobiologists claim that it is just a matter of intensity. I do suffer from seasonal-independent depression. Although I am slightly happier under Ecolume illumination, I doubt that it is really reduces depression per se (as opposed to Paxil which really works). I do vouch that Ecolume illumination reduces eyestrain and related headaches and this probably accounts for most of the happy effect, plus a placebo effect from all of my recent literature review. ---- 11. Electronic vs Magnetic Ballasts ----- Classical fluorescent ballasts are "magnetic" transformers which cycle at 60hz. This can cause flicker, buzz, and radio interference. Newer electronic ballasts cycle at about 20,000 Hz and do not flicker, buzz, nor interfere with radios; they are also more efficient. Some of the full spectrum non-compact tubes are only available as "T-12s" and/or "T-10s" (1.5 and 1.25 inch diameter tubes) which only work with magnetic ballasts. A few brands are also available as "T-8s" (1 inch diameter tubes) which require electronic ballasts. The most recent development in non-compact tubes are T-5s with matched high efficiency electronic ballasts. For epson prints, the closest product of interest would be the 4100K/82CR1 triphosphor Pentron from Sylvania (but these are hard to get)... http://www.sylvania.com/prodinfo/business/fluorescent/t5.htm ---- 12. Polarized Lighting ----- Polarizing the illumination cuts down glare (at least under some conditions). Old style polarizing film (gray or amber stuff) absorbs too much of the light, but there are new developments in almost-practical polarizing technology... http://www.mmm.com/cws/lighting.html https://www.mmmdirect.com/mousepad/catalog.cfm http://www.virtualdaylight.com/frames.html http://www.polarizedlighting.com/ ... I don't see how 3M polarizing sleeves for 4 foot tubes (2nd link) could remain polarized once placed behind a diffuser, the 3rd link interests me the most but may not be available in the USA, the 4th link stinks of "multi-level marketing" recruitment hype. ---- 13. CRI versus other color quality measures ----- "True" color temperature ratings only apply to incadescents (including halogens). Fluorescents with identical "correlated" color temperature ratings may possess drastically different spectra (eg., continuous flat vs triphosphor) and drastically different CRI ( or related) ratings. I would have assumes that full spectrum bulbs with continuous and flat spectra would have superior CRI ratings than discontinuous triphosphors or hybrids, but this is not necessarily true, as can be seen with the comparison between a "full spectrum" Philips Colortone 50 versus a "hybrid" Philips 950... http://www.lighting.philips.com/nam/prodinfo/fluorescent/p5037_02.shtml ... but at least the C50 beats the triphosphor Ultralume 50. This page also discuses the limitations of "CRI" as a measure for illumination quality. More on light quality and the human visual system, including limitations of the "lumen" and "foot-candle" units of intensity... http://www.taiowa.com/dtbsof.htm http://www.soluxtli.com/edu13.htm ---- 14. more compact fluorescents: intro & integral ----- Compacts which screw into regular incadescent sockets may be either "integral", in which case the fluorescent tube and adapter ballast are fused into a single unit, or "modular", in which the tube plugs into a separable adapter ballast. The integral or modular adapter may be either a magnetic or electronic ballast. A fifth option are fixtures into which a compact is plugged in; some of the previously listed aquarium lighting links offer some exotic examples of these. I'm only going to cover compact screw ins with integral or modular electronic adapters, with color temperatures above 2700K. I don't have spectra for any compacts. Vita-Lite Spiralux 5500K/9xCRI (I assume that their spectra are similar to other Vita-Lites; these are too expensive)... http://www.taiowa.com/dtsp1.htm http://jademountain.com/compactfluorescents.html Verilux 6500K/85CRI integral compacts (full spectrum, triphosphor, hybrid???; these are too expensive)... http://www.ergolight.com/products8.html Philips 17W 5000K (?) integral compact that I saw at Home Depot (white color looks nice in store, but too expensive per lumen)... http://www.I-can't-find-at-Philips-website.com/ Let me repeat the Lumiram Ecolumes which I have tried and loved ("3500K", no spectra)... http://www.lumiram.com/html/LRBEcolu.html http://store.yahoo.com/comfort/comfluorligb.html 5000K/85CRI integral compacts, 23W & 26W (price per lumen is good, I'll get a couple)... http://www.fullspectrumsolutions.com/Fluorescent.htm USPAR 4100K/80CRI integral compacts (price per lumen is good, CRI quoted from personal communication with USPAR, probably a triphosphor)... http://www.colehardware.com/hotline/99/02/ecosaver.htm 5000K/84CRI Sun-A-Lite integral compacts (way too expensive!)... http://www.sunalite.com/s_lightbulbs.html http://jademountain.com/compactfluorescents.html 5000K/82CRI Ott integral compacts (way too expensive, possibly available at Home Depot)... http://www.ottbiolight.com/Compact.htm Triten 50 Compacts (way too expensive locally, second link stinks of multi-level marketing scheme)... 5000K/88CRI Panasonic triphosphor (or hybrid?) integral compacts... http://www.panasonic.com/MHCC/pl/capsu.htm http://www.panasonic.com/MHCC/pl/technoi.htm http://www.efficienthome.com/index2.htm 6500K integral compacts (CRI not listed, electronic vs magnetic adapter not listed)... http://www.amazinglightbulbs.com/fullspectrum.html 4100K & 6500K (82CRI?) Mitor integral compact fluorescents http://www.mitor.com/catalog/mtl20f.html 3000K (82CRI?) Sylvania integral compact fluorescents (is the color temperature too close to the ugly 2700K compacts???)... http://www.sylvania.com/prodinfo/business/fluorescent/swdxel.htm http://www.sylvania.com/prodinfo/business/fluorescent/specs.htm A truly novel 3000K/82CRI GE "Genura" integral compact "fluorescent" (is the color temperature too close to the ugly 2700K compacts???)... http://www.gespectrum.com/inet/business/products/genura.htm http://www.gespectrum.com/inet/business/products/genurab.htm ---- 15. more compact fluorescents: modular ----- 3500K/82CRI modular GE 2D lamps... http://www.gespectrum.com/inet/business/products/2d.htm http://www.gespectrum.com/inet/business/products/2db.htm Screwin electronic ballast adapters for plugin compacts... http://www.mitor.com/catalog/mpcen26-32tf.html http://www.mitor.com/catalog/mpcen26-32tb.html http://www.mitor.com/catalog/mpcen42tf.html http://www.mitor.com/catalog/mpcen42tb.html http://store.yahoo.com/springlamp/modsprin.html http://store.yahoo.com/springlamp/elbalad4pins1.html http://store.yahoo.com/springlamp/elbalad4pins.html 4100K/84CRI and 5000K/88CRI Panasonic plugin fluorescent tubes... http://www.panasonic.com/MHCC/pl/compac.htm 3500, 4100 & 6500K (all 82CRI) Mitor plugin fluorescent tubes... http://www.mitor.com/catalog/mte18f.html http://www.mitor.com/catalog/mte18b.html 3500 & 4100 (all 82CRI) GE & Sylvania plugin fluorescent tubes... http://www.gespectrum.com/inet/business/products/biax.htm http://www.gespectrum.com/inet/business/products/biaxb.htm http://www.sylvania.com/prodinfo/business/fluorescent/dultein.htm http://www.sylvania.com/prodinfo/business/fluorescent/specs.htm ---- 16. Added in proof ----- Yet another Vita-Lite spectrum ("doctored" but not "deceptive")... http://www.taiowa.com/dtguide.htm GE ecolux 3500 & 4100K at 86CRI T8 specs (no spectra, probably triphosphor or hybrid)... http://www.gespectrum.com/inet/business/products/ecoluxb.htm http://www.gespectrum.com/inet/business/quality.htm -- Ben Haskell - Turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for list instructions.
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