Solves are a means of simplifying description of the lens system and of accelerating the optimization process. Simply put, a solve enables a surface to dynamically update depending on the paraxial properties of the system. Note that solves are implemented during the paraxial setup, before any real rays are traced. Solves are "forward only" in the sense that no solve can change things so that previous solves must be re-evaluated.
Supported solves
Curvature solves
- Fixed
- Variable
- Marginal ray angle specified
- Chief ray angle specified
- Pick up from any previous surface
- Marginal ray normal to the surface
- Chief ray normal to the surface
- Aplanatic
- Concentric with any previous surface
- Concentric with center of curvature of any previous surface
- Paraxial F/# specified
Thickness solves
- Fixed
- Variable
- Marginal ray height specified
- Chief ray height specified
- Edge thickness specified
- Pick up from any previous surface
- Position (length between specified surface and the next surface is fixed)
- Compensator (sum of two thicknesses is fixed)
- Center of curvature (put next surface vertex at the center of curvature of the specifed surface)
Semidiameter solves
- Automatic (determined by paraxial ray bundle)
- Pick up from any previous surface
- Maximum aperture consistent with surface (reverts to automatic if infinite)
- Fixed
Parameter solves
- Fixed
- Variable
- Pick up from any previous surface, scaled and offset
Glass solves
- Fixed
- Pick up from any previous surface
Model glass solves
- Glass parameters can be fixed or variable.