Daylight color = horrible headache « on: March 07, 2012, 11:12:05 PM » Author: RyanF40T12
I had to spend close to 2 hours today inside of an office that had nothing but the daylight color T-8s.  After 30 minutes, I started getting a severe headache.  The moment I stepped out of that office and back into the rooms that had 3000-3500k warm white, the headache was gone.  Wow, now I know to avoid the daylight colors.
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	Re: Daylight color = horrible headache « Reply #2 on: March 08, 2012, 10:27:01 AM » Author: dor123
I don't see a problem with daylight color in offices, and I'm gets along well with the daylight halophosphors T12/T8 lamps in the storage of Carmel hospital. Warm white is mostly suitable for homes. I prefering 3500-4000K for my rooms in my mother and father homes and the hostel i live in. When the OEM generic Hyundai 21W 6500K T5 HE will reach EOL, i have a spare Osram FH 21W/840 4000K T5 lamp.
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	Re: Daylight color = horrible headache « Reply #3 on: March 08, 2012, 02:56:12 PM » Author: Medved
@Ryan:   Weren't those lamp flickery and/or glary? It is strange, I have no problems with light color, but if the lights are glary, I do not feel good there.
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	Re: Daylight color = horrible headache « Reply #5 on: March 08, 2012, 04:05:51 PM » Author: Powell
I would prefer 5500K Vitalite. Snark!  DuroTest gone !  There are a few that come close. I have 2 fixtures in a small control room in the radio station... 2 4 lamp fixtures next to each other. So in one I have 90CRI  5000K lamps and in the other  6500K DX lamps.  It's bright but not glary. Cool white in that room made the room look gloomy. To me low CRI Cool White is glooooooooooomy ! ! !
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	Re: Daylight color = horrible headache « Reply #6 on: March 08, 2012, 06:35:37 PM » Author: RyanF40T12
I just think my situation is unique.  With the church buildings that I take care of lamp wise, they started replacing EOL tubes that were originally Warm White with 4000K cool white and did that for about 10-12 years and then as the older buildings saw all the warm whites replaced, people started complaining of headaches and things being too bright and crisp,and even I felt that way so now they are going back to 3000K-3500K and already people can tell a difference in the classrooms and hallways that have gone back to the 3000-3500K colors, people seem to be more at ease and not having the headaches like they were.  I guess I can be counted as one of them as anything 4000K and over is just too bright for my eyes
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	Re: Daylight color = horrible headache « Reply #7 on: March 08, 2012, 10:22:38 PM » Author: Powell
If I had to use a warm color, I'd chose one with a high CRI such as SPX30. Phillips has a K&B clone that is ultra bright and 90 CRI.  Cool White = NEVER!  Cool White Deluxe only if I had to.  The 3700 Natural with a shading of pink is very nice, very expensive.... 90 CRI
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	Re: Daylight color = horrible headache « Reply #8 on: March 09, 2012, 02:11:27 PM » Author: Medved
What I do not like with fluorescents is anything off-white (technically speaking it mean off the blackbody curve, but the color temperature does not matter as much). So should not be greenish or pink or so, it should have good balanced spectrum fro the given CCT. One exception is the clear MV (greenish-bluish; but it have to be really a genuine clear MV, not faked by LED stuff), but that i more like I rather enjoy "I have something unique" (clear MV disappeared in Europe many decades ago) than really be so comfortable with that...
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	Re: Daylight color = horrible headache « Reply #9 on: March 09, 2012, 11:25:27 PM » Author: dor123
Daylight lamps are best for outdoor lighting, as their light is rich in blue and therefore can have better visibility with low lighting levels during nightvision.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.

I only working with the international date format (dd.mm.yyyy).

I lives in Israel, which is a 220-240V, 50hz country.

	Re: Daylight color = horrible headache « Reply #11 on: March 11, 2012, 02:21:34 PM » Author: Medved
Quote from: Ash on March 11, 2012, 11:42:45 AM Flickering at 100 (or 120) HZ can happen with both magnetic (bad lamps or line ? - unsure but i did see it happen) or electronic (bad capacitor) 100/120Hz flicker is normal on all magnetic (it can not be otherwise - the 50/60Hz AC have two points in the period, where the current have to cross the zero). What is not normal is the 50/60Hz flicker. That mean the lamp rectify, so it is good idea to replace it, as it is going to die soon anyway. Many electronic ballasts are on purpose designed with very small value bus filter capacitor in order to increase the power factor on the ballast input (for older standards and/or lower power level it is sufficient method). Even with active PFC the minimum value capable to handle the ripple current tank capacitor is used, yielding the 100/120Hz flicker as well. So in these cases the 100/120Hz flicker is normal too...
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	Re: Daylight color = horrible headache « Reply #13 on: March 13, 2012, 10:38:59 AM » Author: dor123
Quote from: Ash on March 11, 2012, 11:42:45 AM CRI may be low and i dont know whether this is contributing factor too Ash: CRI is also an important factor too. If the lamp CRI is low, colors willn't be rendered correctly and the light will be unpleasant in home applications.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.

I only working with the international date format (dd.mm.yyyy).

I lives in Israel, which is a 220-240V, 50hz country.

	Re: Daylight color = horrible headache « Reply #14 on: March 13, 2012, 04:25:15 PM » Author: Medved
What really is unpleasant is (randomly) varying color tone over multiple fixtures (unless it is some contrast accent lighting; then the CCT should really make the contrast - but only lower CCT accent spot with higher CCT background is acceptable, the opposite is unnatural too). It make "colored" shadows and that look really strange.
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