
Using the OSC fan
The OSC (Offense against the Sine Condition) is a plot of OSC versus pupil coordinate that allows you to judge the zonal contribution to coma.
To open the OSC window:
- Select from the menu Analysis > Fans > OSC

The OSC is displayed as a function of the normalized pupil coordinate. A tangential scan is made, using the y radius of the entrance pupil. The options button will summon a utility window that will let you change the number of points at which the OSC is calculated.