Broadening due to extended conditions may result from changes to the spectral distribution of the radiation as it traverses its path to the observer.

So a lumen represents at least 1/683 watts of visible light power, depending on the spectral distribution.

"Those for which the spectral distribution of energy is identical with that given by the Planckian formula."

Colored objects are perceived differently under light sources with differing spectral distributions.

But in that case there would not be a blanket of air to alter the "spectral distribution".

Some studies attribute migraine headaches to overly intense light, while others linked it with certain spectral distributions.

To compare "full-spectrum" sources requires direct comparison of spectral distributions.

Jim Swenson You have to be very careful in distinguishing the spectral distribution of light from its "color".

Most of the spectral distribution is confined to the central maximum which has a positive upper frequency boundary of.

Its quantity and spectral distribution depends on the material and its temperature.