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Tutorial 13 - Field Stops and Pupil Matching

This video continues the discussion of stops by looking at the field stop. Apertures stops are reviewed to prepare us to discuss pupil matching.

Here is the homework:
Numerically design a 5x afocal Galilean Telescope. Assume the apertures stop is at the objective and it operates at F/5, Eye relief is 15 mm, Eye pupil is 5 mm in diameter
1) Report objective focal length
2) Report eyepiece focal length
3) Report Entrance pupil location

Repeat above exercise for a Keplarian Telescope, ensure a pupil is located on the front objective. The field stop is a 10 mm diameter reticule located at the intermediate image
4) Report objective focal length
5) Report eyepiece focal length
6) Report system angular full field of view

A 35 mm focal length Double Gauss has an exit pupil 100 mm from the image plane. A 0.27x telecentric is placed after the Double Gauss
7) Where can a lens be placed to match the pupils, such that the system focal length is the product of the Gauss EFL and Telecentric Mag?
8) What is the new lenses focal length?
9) The Double Gauss is F/2.8 with a 5 mm aperture stop. The telecentric operates at F/5.6 working with a 6 mm aperture stop. Which aperture becomes the system aperture stop?
10) The telecentric is design for a 1/2” sensor. The Double Gauss is designed for a 1” sensor. Which optical assembly limits the field of view? (i.e. based on the design which would be the field stop?)

Solutions here.

Here is the animated GIF showing  how the field stop controls the field of view:

Scott Sparrold,
Jun 7, 2014, 5:38 AM