To determine whether the sky psychological haze even covered with dark clouds is the only factor in yourself, can't let oneself always have a sunny mood itself is a failure.
Young magical sky always show color, when day after day, boring life so that we can not stand, doomed from the moment the outbreak of rebellion factor, and out of control.
This paper suggests a zenith luminance converting factor. By means of multiplying outdoor horizontal sky illuminance by this factor, the value of zenith luminance of the sky can be obtained.