In , Paul M. Eldridge wrote:
On Sun, 4 May 2008 11:42:11 -0700 (PDT), ransley
wrote:

Cool white or daylight flourescent I hate and always have, warm white
is fine for me, I know a camera store that put in Daylight T8, their
store is empty, the employees hate it but the owner likes it.

Hi Mark,

With the exception of some high-end retailers, cool white (4,100K) and
HID (typically 3,700K and higher) dominate the retail world and while
some commercial office spaces will opt for 3,500K lamps, 4,100K pretty
much rules the day.

As a lighting designer, I'm seeing a notable shift towards 5,000K. Our
firm has done several side-by-side mock-ups in offices and on
industrial floors and we've found the vast majority of employees
prefer the higher colour temperature (next to each other, the part
that is illuminated at 4,100K looks "dull", "dingy" and "dirty" by
comparison).

This does vary with brightness of the illumination. 4100K looks good to
me at 900-1,300 lux. 5000K at that illumination level often looks a bit
stark, though individual illuminated items look good if the lamps are
"850" or "SPX50" ones or are rendered well regardless of lamp spectral
properties. But the room as a whole can still appear a little icy cold or
"stark", and non-triphosphor lamps can give a bit of "dreary gray effect".

I have yet to see much usage of 5000K. Is this a coming fad?

I have noticed that the Target stores in my area use 3000K lighting - it
seems stuffy to me. I wish they would use 3500K - still warm but not
stuffy.

I have seen some stores use 6500K, even 6500K T8 lamps - that looks icy
cold and stark at best to me even at a couple thousand lux, and has
(to me at least) a "dreary grayish" effect if the lamps are not
triphosphor ones.
I see 6500K used about as much as 5000K. And I see a difference - 6500
is definitely bluish to me as far as fluorescent lighting goes, while 5000
is "icy pure white that sometimes looks a tiny bit bluish".

As for home use - usually illumination levels are a lot less than 1,000
lux, and 4100K is often "too high" there. I mostly like 3500K for home
use, though dimmer areas can look a bit dreary unless color temperature
gets even lower (warmer).

- Don Klipstein )