计算机辅助光学的设计 code V S1.ppt

May 1998 Introduction to CODE V, Page # CODE V Introductory Seminar: Day 1“Optics 101”Digital Camera Design Study Section 1Optics 101(on a Budget) Goals and “Not Goals” Goals: Brief overview of basic imaging concepts Introduce some lingo of lens designers Provide resources for quick reference or further study Not Goals: Derivation of equations Explain all there is to know about optical design Explain how CODE V works Sign Conventions Distances: positive to right Curvatures: positive if center of curvature lies to right of vertex Angles: positive measured counterclockwise Heights: positive above the axis Light from Physics 102 Light travels in straight lines (homogeneous media) Snell’s Law: n sin q = n’ sin q’ Paraxial approximation: Small angles: sin q~ tan q ~ q; and cos q ~ 1 Optical surfaces represented by tangent plane at vertex ignore sag in computing ray height thickness is always center thickness Power of a spherical refracting surface:1/f = f = (n’-n)*c Useful for tracing rays quickly and developing aberration theory Cardinal Points 6 important points along the axis of an optical system 2 focal points (front and back): input light parallel to the axis crosses the axis at focal points F and F’ 2 principal points (primary and secondary):extend lines along input ray and exiting focal ray; where they intersect defines principal “planes” which intersect the axis at the principal points 2 nodal points (first and second): rays aimed at the first appear to emerge from the second at the same angle. “first” points defined by parallel rays entering from the right; “second” points defined by parallel rays entering from the left Cardinal Points Illustrated Effective Focal Length (EFL) = distance from principal point to focal point Aperture Stop Aperture stop: determines how much light enters the system 2 special rays Marginal ray: from on-axis object point through the edge of the stop Chief ray: from maximum extent of object through the center of the st