I would like to learn about telecentric lenses for use in an experiment. So far, I have found scant resources (mostly optical companies) and I understand the basic principal of a simple telecentric setup from the figures therein.
However, one thing that I definitely do not understand is the working distance of a telecentric lens. One of the tutorials has stated that one encounters distortion when an object is imaged outside of the working distance... However, I have no idea how to calculate this distance so that something can be designed for my own setup.