How do you require a system to be telecentric in image space?
One way is to use the RANG operand. Require the RANG of the chief ray (hx=0, hy=1, px=0, py=0) to have a value of 0 in image space. This implies the chief ray is parallel to the optical axis, which means the exit pupil is “at infinity”. The optimization algorithm will have to be run before the system actually becomes telecentric, and there must be sufficient variables (radii, thicknesses) to allow the design to reach the telecentric condition. The same trick works in object space.
