Uncovering A Problem With The Lumen
Lighting Science
Lighting History
Lighting and Human physiology
100
Area of our vision comprised of only cones and no rods
What is the fovea?
100
Color/wavelength of light that most sea animals can see better than us
What is blue/UV light?
Light between the wavelengths of 450-495 nm travel the furthest in water before being absorbed, making it the most available color of light in the ocean.
100
The three different colors of light that the short, medium, and large cone sizes inside the human eye can perceive
What is red, green, and blue?
Due to the fact that our eyes are very good at seeing these colors, we’ve used them as primary colors in all of our screens and denoted a color code based off of having different levels of each of these colors (RGB).
200
This color can rarely flash on the horizon when the sun sets over the ocean
What is green?
200
Production of this chemical that helps us sleep is blocked by short wavelength (blue) light entering our eyes
What is melatonin?
300
The function that translates radiometric energy into photopic values
-What is V(λ)/luminous efficiency function/photopic luminosity function?
300
The color you will see on a white surface after you stare at a red surface for a while
(Hint:)
What is cyan?
300
This complex industry standard, backed by IES and spearheaded by Kevin Houser and his former students, was developed over 18 months to combat a lagging CIE-backed color rendering index.
What is TM-30?
400
The type of cone not present in our center of vision
What is the S cone/blue cone?
Our center of vision is tritanopic. This was observed in 1894 by a German scientist, but was forgotten about it until 1945, when two British scientists independently discovered it and published their findings.
400
The direction that peak luminance shifts as human vision goes from photopic to scotopic
What is towards shorter wavelength/blue/left?
Our rod cells have a different peak sensitivity than our cone cells, meaning that the luminosity of all objects change as light levels decrease. Red decreases in luminosity the most, while green and blue retain their luminosity the most. This is called the Purkinje effect.
500
The problem with the lumen
The blue cone is very under-represented in V(λ)
500
A large range of wavelengths removed from light sources in the transition from incandescent light to LEDs
What is infrared light?
500
The English name of the CIE, which is an abbreviation French name "Commission Internationale de l'Éclairage"
What is the International Commission on Illumination?
500
The reason why looking a few degrees to the side of a star makes it appear brighter to our eyes
What are the traits of scotopic vision?
When viewing a star, incoming light levels are so low that our cones have trouble detecting it and primary brightness perception starts coming from our rods. Since there are no rods in our center of vision, looking a few degrees away will activate more rods and make the star appear brighter.
