V
Victor Roberts
- Jan 1, 1970
- 0
As many of you know, Sam Berman has conducted research for
many years that shows that a light source with a
scotopically-enhanced spectrum will result in reduced pupil
diameter and enhanced vision compared to a light source with
a non-enhanced spectrum that produces the same light levels
when measured with a standard photopically-corrected light
meter. These results were originally attributed to
activation of the rods, which are known to be responsible
for scotopic vision. However, there has always been
controversy about this explanation for the effect measured
by Berman, et.al.
Recently a new photoreceptor that has a peak sensitivity at
about the same wavelength as the rods has been discovered.
Sam believes this new photoreceptor provides a better
explanation for the reduction in pupil diameter with
scotopically-enhanced light.
Sam has written an interesting paper that describes the new
research. Attached below is an abstract provided by Sam and
the link to his paper, which I have posted on my web site.
ABSTRACT
NEW DISCOVERIES IN VISION AFFECT LIGHTING PRACTICE
Sam M. Berman (sam dot berman at comcast dot net)
Senior Scientist Emeritus
Lawrence Berkeley National Laboratory
Berkeley, CA 94720
For more than the last 100 years many lighting users and
practitioners have found that their sense of brightness of
spaces often does not tally with light meter values. Areas
lit by lighting with white light with more of a bluish tint
often appear brighter than the same areas lit by lighting
with more of an orange or reddish tint even though a light
meter may indicate the opposite, (e.g. compare 5000K
fluorescent with HPS). Lighting professionals have puzzled
over this observation for just as long but have failed to
provide a satisfactory explanation. Furthermore for about
the same 100 years most of us including lighting
practitioners have operated under the impression that there
are two photoreceptors in the retina of the eye, namely
cones and rods. However, very recent discoveries in vision
science have determined that there is another photoreceptor
in the eye relatively more sensitive to blue color and whose
responses are not included in the standard calibration of
light meters. This discovery can provide the mechanism for
an objective explanation of the paradoxical brightness
perceptions. Incorporation of this new discovery into
lighting practice will lead to lighting that provides better
vision and energy savings. An overview and some insights are
provided in my article appearing on the website -
http://www.robertsresearchinc.com/P...veries_in_Vision_Affect_Lighting_Practice.pdf
--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.
This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
many years that shows that a light source with a
scotopically-enhanced spectrum will result in reduced pupil
diameter and enhanced vision compared to a light source with
a non-enhanced spectrum that produces the same light levels
when measured with a standard photopically-corrected light
meter. These results were originally attributed to
activation of the rods, which are known to be responsible
for scotopic vision. However, there has always been
controversy about this explanation for the effect measured
by Berman, et.al.
Recently a new photoreceptor that has a peak sensitivity at
about the same wavelength as the rods has been discovered.
Sam believes this new photoreceptor provides a better
explanation for the reduction in pupil diameter with
scotopically-enhanced light.
Sam has written an interesting paper that describes the new
research. Attached below is an abstract provided by Sam and
the link to his paper, which I have posted on my web site.
ABSTRACT
NEW DISCOVERIES IN VISION AFFECT LIGHTING PRACTICE
Sam M. Berman (sam dot berman at comcast dot net)
Senior Scientist Emeritus
Lawrence Berkeley National Laboratory
Berkeley, CA 94720
For more than the last 100 years many lighting users and
practitioners have found that their sense of brightness of
spaces often does not tally with light meter values. Areas
lit by lighting with white light with more of a bluish tint
often appear brighter than the same areas lit by lighting
with more of an orange or reddish tint even though a light
meter may indicate the opposite, (e.g. compare 5000K
fluorescent with HPS). Lighting professionals have puzzled
over this observation for just as long but have failed to
provide a satisfactory explanation. Furthermore for about
the same 100 years most of us including lighting
practitioners have operated under the impression that there
are two photoreceptors in the retina of the eye, namely
cones and rods. However, very recent discoveries in vision
science have determined that there is another photoreceptor
in the eye relatively more sensitive to blue color and whose
responses are not included in the standard calibration of
light meters. This discovery can provide the mechanism for
an objective explanation of the paradoxical brightness
perceptions. Incorporation of this new discovery into
lighting practice will lead to lighting that provides better
vision and energy savings. An overview and some insights are
provided in my article appearing on the website -
http://www.robertsresearchinc.com/P...veries_in_Vision_Affect_Lighting_Practice.pdf
--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.
This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.