1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Telecentric entrance pupil - Optics

  1. Mar 23, 2015 #1
    Hi. As you guys know, an object-telecentric system (a system with constant magnification) has per definition an entrance pupil that is infinitely far away. One can construct such a system by taking a lens and placing an aperture stop (AS) at its focal point.

    My issue is that I am struggling to ray-trace the aperture stop (AS) through the telecentric system. I just can't get the "infinitely far away entrance pupil" condition without also assuming that the aperture stop has a diameter approaching zero.

    I am assuming paraxial approximation and geometrical optics. Is perhaps this the reason behind my difficulties?
     
  2. jcsd
  3. Mar 23, 2015 #2

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor
    2016 Award

  4. Mar 24, 2015 #3
    I think I forgot about the paraxial approximation. With thin lenses and paraxial approximation, any object at a focal point will produce an image infinitely far away from the lens. In this case the object is the aperture, and hence its image will be infinitely far away.

    Anyway, if you are skilled with optics, could you please help me here? https://www.physicsforums.com/threads/optics-newtonian-telescope.804709/ I simply can't seem to find the entrance and exit pupils!
     
  5. Mar 25, 2015 #4

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor
    2016 Award

    I don't know about 'skilled', but I responded to the above thread....
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Telecentric entrance pupil - Optics
  1. Telecentric lens (Replies: 13)

Loading...