When a full (or near-full) moon rises or sets right at the horizon while the sky is already dark, the enormous moon disk becomes a natural backdrop for silhouettes. Photographers position themselves far from a well-known landmark - a church spire, a lone tree, a person on a ridge - so that a telephoto lens compresses the subject against the moon. The result: a tiny, sharp silhouette framed inside the massive glowing circle.
Inverza checks moon illumination (greater than 85%, covering the full moon plus or minus 2 nights), confirms the sun is at least 4 degrees below the horizon (blue hour or darker), and verifies the horizon is clear of cloud cover. The condition fires at the exact moment of moonrise or moonset - whichever scores higher - and includes the precise compass direction so you know where to position yourself. This uses terrain-adjusted times because you need to know when the moon physically clears the terrain at your location.
