
Definition of surfaces
This page describes the object, system, focus, and image surface.
- Object surface
- This is "surface 0", the first surface appearing in the surface data editor spreadsheet. The distance between this surface and the system surface can be infinite, for the case where the object is at infinity.
- System surface
- This is the first surface after the object surface that is not a coordinate break. Without coordinate breaks, this is "surface 1", the second surface appearing in the surface data editor spreadsheet. If the object is at infinity, rays begin their life just before the plane of this surface.
- Focus surface
- This is the surface whose thickness is adjusted to focus. It is the last surface that is not the image surface and not a coordinate break.
- Image surface
- This is the last surface appearing in the surface data editor spreadsheet. The thickness of this surface and its glass type do not enter into any calculations.