Many photographers pack up right after sunset - and miss the best part. The afterglow happens 10-25 minutes after the sun dips below the horizon, when high clouds continue to catch warm light from below. The colors can be even more intense than the sunset itself, shifting from gold through pink to deep purple.
The detection mirrors Colorful Dawn but in reverse: Inverza checks for high cloud coverage, a clear horizon toward the sunset direction, low humidity, and dry weather. The condition uses the sun's geometric position (not terrain-adjusted), because atmospheric color depends on the sun's angle relative to the true horizon, not local mountains.
Tip: Don't leave after sunset. Watch the sky for 20 more minutes. The afterglow often peaks when most people have already gone. Silhouettes against the glowing sky work beautifully.
