Hi everybody, I’m a new user of Zemax, I did some tutorial so I begin to know the functionalities of the soft. But my major trouble comes from the fact that I don’t know really the procedure, the drill.. to make a system from particularities data. For example, I try to do the exercises of the book “Introduction to lens design with Zemax practical example” by Joseph M. Geary. The first homework is a simple lens design from several points, and I have to calculate the mains characteristics. Input data: Infinity objet (20mm semi diameter) Field : 2 incidence: 0° and 5° Format size of the IMA : rectangular. Aperture stop: 20 mm semi diameter (plane surface) Thickness between Aperture Stop and first lens surface: 0 Equiconvex lens Fnumber: f/10 Lambda: 587nm Lens Material: BK7 Data to calculate: EFL Lens Power Lens thickness Radius of curvature R1 and R2 Format size of Ima Airy disk diameter. I don’t get to choose the good variables in my system, which cell must be define with marginal ray, chief ray…where start ?!?! I hope somebody could help me. Thank you for your replies.