1. Light and Vision Flashcards
Between what electromagnetic energy wavelengths does the human eye respond to?
Ultraviolet and Infrared
Light
Definition
Electromagnetic energy.
What portion of the spectrum is the human eye most responsive to?
(Colour)
Yellow-Green
Light output measured in…
unit
Lumens (lm)
Luminous Intensity is the…
Intensity of light.
Luminous Intensity measured in…
Unit
Candelas (cd)
When light strikes a surface, it is called…
Illuminance
Illuminance is measured in…
Unit
Footcandles (fc)
1 footcandle (fc) =
The illumination on a surface one foot away from a “standard candle.”
a.k.a. One lumen per square foot.
Brightness
Definition
Light transmitted/reflected off of a surface.
Brightness is also called…
Luminance
How is Luminance measured?
Candelas per square meter.
cd/sq. m
Visual Field
Definition
The area the eye sees.
In degrees, what is the area that the eye can see?
180 degrees in the horizontal plane
130 degrees in the vertical plane
In degrees, the area of sharp detail that the eye can see…
2 degrees
