Step 5 of 8: Find the distance to the next surface

This is easy. The tricky part is that what is measured is the distance to the next surface. Thus, the object (OBJ) distance is

OBJ distance

The distance of the first surface (the AST surface) is the thickness of the lens from vertex to vertex

AST distance

The distance for the second surface is the length to the image surface. You don't need to set this distance because OSLO can calculate it for you.

surface 2 distance

So, now add these distances into the table describing your optical system.

Surface Curvature Distance Height Material
OBJ 0 Dobj
AST Rast Dast
2 R2 D2
IMS 0 (calc)