Casting Composite charts is easy once you know how to create Synastry & Biwheel charts:
- Create a biwheel between any two (2) radix charts.
- [Desktop] On the right side of the screen, select Composite Generator from the Chart Menu.
- [Mobile] Expand the Chart Menu drawer and tap the Composite Generator link.
FYI
At this time, LUNA only supports casting Composite Midpoint charts. Other composite chart types such as the Derived Ascendant and Davison Relationship chart are currently under development.
Switch Between Biwheels & Composite Charts
When viewing a Composite chart, you can easily switch back to the biwheel chart by selecting the Convert Uniwheel to Synastry link from the Composite Generator panel.
Select the Midpoint Base
The Midpoint Base is a setting that’s needed to accommodate two (2) different approaches to generating the houses of a Composite Midpoint chart.
Composite Midpoint charts are calculated by finding the midpoint between all chart points of the two (2) charts in question:
Midpoint Composite Sun = (Chart A's Sun + Chart B's Sun) / 2.To calculate the angles and the houses, the same calculation is applied. However, this can result in incoherent houses if the midpoints of each house cusp are used in their standard order.
Take the following scenario for example:
| House | Chart A | Chart B | Midpoint |
|---|---|---|---|
| 1st | 19° Aquarius | 13° Virgo | 1° Sagittarius |
| 2nd | 27° Aries | 8° Libra | 17° Cancer |
| 3rd | 27° Taurus | 7° Scorpio | 17° Leo |
| 4th | 16° Gemini | 11° Sagittarius | 13° Virgo |
| 5th | 1° Cancer | 15° Capricorn | 8° Libra |
| 6th | 18° Cancer | 16° Aquarius | 2° Taurus |
| 7th | 19° Leo | 13° Pisces | 1° Gemini |
| 8th | 27° Libra | 8° Aries | 17° Capricorn |
| 9th | 27° Scorpio | 7° Taurus | 17° Aquarius |
| 10th | 16° Sagittarius | 11° Gemini | 13° Pisces |
| 11th | 1° Capricorn | 15° Cancer | 8° Aries |
| 12th | 18° Capricorn | 16° Leo | 2° Scorpio |
As you can see from the table above, the midpoints of each house are not in zodiacal order. When this happens, LUNA will sort the house cusps in zodiacal order but needs to know whether counting should start at the Ascendant or the Midheaven.
In this example, if the Midpoint Base is set to the Ascendant, then 1° Sagittarius will be the 1st house cusp and Ascendant of the Composite chart. The 2nd house cusp would then be 17° Capricorn, the 3rd house cusp 17° Aquarius and so on.
If, on the other hand, the Midpoint Base is set to the Midheaven, then 13° Pisces will be used as the 10th house cusp and Midheaven of the Composite chart. The 11th house cusp would then be 8° Aries, the 12th house cusp 2° Taurus and so on.
