Zemax surface curvature in X and Y direction calculation ?

  • 10 July 2024
  • 1 reply

Hi Community,

I am confused by the way Zemax calculate surface curvature in X and Y direction. Consider a very simple case: a sphere.Take  latitude direction as X axis and  longitude direction as Y axis, and pick up 3 points P1,P2,P3 in different latitude circle. You will see each latitude circle has different circular radius. SO I will expect surface cross section curvature analysis (or use SCUR operand for data 4/5) will give different curvature values in these positions,

BUT OpticsStudio always give same value constant equal to sphere curvature. Same true for use SCUR(data 4/5 for XY direction, even  data 0/1 for tan/sag direction).

So what happened here? Did I miss something simple?  thanks

Eric Yu



1 reply


The knowledge base article ‘Understanding the geometry in OpticStudio Curvature Cross-Section analysis’ authored by Shawn Gay doesn’t explain this discrepancy (I mean sphere case above).