Campanus

How it divides the sky

Campanus uses the "prime vertical" plane — the plane passing directly above the observer's head, perpendicular to the east-west axis. This plane is divided into 12 equal arcs and projected onto the ecliptic. Quadrant-based; mathematically elegant but with strong latitude effect.

When to use it

Used in academic/mathematical astrology. In practice, Placidus and Regiomontanus are more common. If you think prime-vertical based or want astronomical elegance, Campanus.

History

Campano published in the 13th century; respected in medieval Europe but overshadowed by Regiomontanus.