Crucial Astro Tools
Primary Mundane / Primary Zodiacal options
New in Solar Fire Gold Version 9

Placidus or Regiomontanus methods for computing directions

 New rate keys

Classical or Modern definitions of Converse

Expert astrologers can now enjoy our revised and expanded the range of Primary Directions reports available through the Dynamic Reports feature.

Solar Fire now has “Primary Zodiacal” directions as well as revamped “Primary Mundane”. Previously, Solar Fire computed Primary Directions according to the semi-arc technique promoted by Placidus. Solar Fire now allows you to choose between Placidus’ semi-arc projections and Regiomontanus’ preferred projections based on hour circles to determine mundane position.

You may also notice that Solar Fire now computes Primary Directions to Radix much faster and enables several more “rate keys” available in the Preferences / Settings / “Progs/Dirns” tab including Cardan’s key (59 degrees 12 minutes),

Placidus’ key (based on the true solar arc in Right Ascension), Solar Birthday Longitude (similar to Kepler’s key, but  longitude instead of right ascension), User-determined rate. Solar Fire has also added an option for the Classical Converse or the Modern Converse methods. These are two different approaches to computing converse Primary Directions. 

The Classical converse is computed. by switching the two points being compared, while the Modern converse (in use since the 19th century) is computed by reversing primary motion.