Glossary Of Terms - Navitar EX Instruction Manual

Glossary of Terms

Color Rendering Index (CRI) A rating system that
describes the effect of a light source on the color ap-
pearance of objects (compared to a standard reference
source of the same color temperature). A rating of 100 is
the highest possible CRI. Typical cool white fl uorescent
lamps have a CRI of 62. Lamps with rare-earth phos-
phors can have a CRI of 80 or higher.
Color Temperature The color a light source appears to
be, ranging from reddish (lower color temperatures) to
bluish (higher color temperatures). Measured in degrees
Kelvin (ºK).
Diffused Light Produces a soft light with soft shadows
while illuminating a relatively large area. Illumination is
indistinct rather than obvious, distinct light beams.
Fill Light Supplementary illumination positioned to
reduce or eliminate shadows created by key light.
Flare Over-saturation of light that appears when too
much light is picked-up by a camera's lens and refl ected
off its internal glass elements.
Foot Candle (fc) A measurement of illumination where
one unit is equal to the light of a candle at a distance of
one foot.
Glare A condition caused by light within the visible fi eld
that is brighter than the level of light to which the eyes
are adapted.
Key Light The principal directional light. Usually posi-
tioned off-center and angled towards the subject.
Three-point Lighting A basic lighting method in which
key light, fi ll light and back light are all used to illuminate
the subject while providing depth and texture.
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