D
Don Klipstein
- Jan 1, 1970
- 0
So far until tonight, I have thought that there was no official
definition of "full spectrum".
Now, I had a look at:
http://www.venturelighting.com/NaturalWhite/NaturalWhite_FAQs.html
My take is that this is a bit hyped, somewhat along the lines of hype
that could get worse if there was an "official definition" of "full
spectrum".
For one thing, that article does appear to me to overemphasize value of
higher s/p ratio, which I sense has been "fashionable" to do nowadays.
They say how higher s/p ratio makes a lamp better for outdoor
illumination (which I think is fairly true), but they talk about s/p ratio
until they say "Bring Daylight Indoors!"
I surely like most of my indoor lighting to be "warmer". I have a very
strong liking to about 3600-3800 K or so, 4100 K when I can practically
achieve a kilolux or two, and 3400-3500 K looks good to me at 300-500 lux
or so. At 100-200 lux, 3000-3200 K or so looks good to me!
At 50-100 lux, I like 2700-2865 K. At 30-50 lux, I like 2700 K. When
the illumination level needs to be less than 30 lux, I either like
"utility high-s/p-ratio-daylight" if I want "maximum illumination power
per watt" at expense of appearing "stark" and "dreary gray", or else I
like flamelike lower color temp. incandescent (or good high-CRI
equivalent) with color temp. close to 2500 K. And in a bedroom to enter
along with a spouse (or girlfriend/boyfriend) while carrying full wine
glasses and dressed skimpily, probably 1700-2000 K if the color is
going to approach blackbody.
One thing they did say:
"The IESNA Lighting Handbook (3-26) defines full spectrum lighting as
having spectral emission in all parts of the visible spectrum and in the
the near UV, with a correlated color temperature of 5000K or more, and a
CRI of 90 or more."
Does any edition of the IESNA Lighting Handbook actually define "full
spectrum" or "full spectrum lighting" as claimed above?
Why should 7500 K qualify as "full spectrum" while 4800 is "disqualified
from being full spectrum" when 5400 K is the CCT if "equal energy per unit
wavelength"? Should not mid-4,000's or maybe even low-4,000's qualify for
"full spectrum"?
Does 9300 K or 10,000 K shade of "lighter sky blue" qualify as "full
spectrum"? Does 20,000 K "deeper sky blue" qualify as "full spectrum"?
If so, should not a carbon arc at 3800-3900 K qualify as "full spectrum"?
Any and all comments please!
- Don Klipstein ([email protected])
definition of "full spectrum".
Now, I had a look at:
http://www.venturelighting.com/NaturalWhite/NaturalWhite_FAQs.html
My take is that this is a bit hyped, somewhat along the lines of hype
that could get worse if there was an "official definition" of "full
spectrum".
For one thing, that article does appear to me to overemphasize value of
higher s/p ratio, which I sense has been "fashionable" to do nowadays.
They say how higher s/p ratio makes a lamp better for outdoor
illumination (which I think is fairly true), but they talk about s/p ratio
until they say "Bring Daylight Indoors!"
I surely like most of my indoor lighting to be "warmer". I have a very
strong liking to about 3600-3800 K or so, 4100 K when I can practically
achieve a kilolux or two, and 3400-3500 K looks good to me at 300-500 lux
or so. At 100-200 lux, 3000-3200 K or so looks good to me!
At 50-100 lux, I like 2700-2865 K. At 30-50 lux, I like 2700 K. When
the illumination level needs to be less than 30 lux, I either like
"utility high-s/p-ratio-daylight" if I want "maximum illumination power
per watt" at expense of appearing "stark" and "dreary gray", or else I
like flamelike lower color temp. incandescent (or good high-CRI
equivalent) with color temp. close to 2500 K. And in a bedroom to enter
along with a spouse (or girlfriend/boyfriend) while carrying full wine
glasses and dressed skimpily, probably 1700-2000 K if the color is
going to approach blackbody.
One thing they did say:
"The IESNA Lighting Handbook (3-26) defines full spectrum lighting as
having spectral emission in all parts of the visible spectrum and in the
the near UV, with a correlated color temperature of 5000K or more, and a
CRI of 90 or more."
Does any edition of the IESNA Lighting Handbook actually define "full
spectrum" or "full spectrum lighting" as claimed above?
Why should 7500 K qualify as "full spectrum" while 4800 is "disqualified
from being full spectrum" when 5400 K is the CCT if "equal energy per unit
wavelength"? Should not mid-4,000's or maybe even low-4,000's qualify for
"full spectrum"?
Does 9300 K or 10,000 K shade of "lighter sky blue" qualify as "full
spectrum"? Does 20,000 K "deeper sky blue" qualify as "full spectrum"?
If so, should not a carbon arc at 3800-3900 K qualify as "full spectrum"?
Any and all comments please!
- Don Klipstein ([email protected])