Eyepiece Design
An eyepiece differs fundamentally from a photographic objective in that the entrance and exit pupils are outside the system. The lens itself must therefore have a large diameter, which is determined far more by the angular field to be covered than by the relative aperture. The latter is set by the objective lens and has little relation to the structure of the eyepiece itself.
So far as aberration correction is concerned, the axial spherical and chromatic are usually unimportant, and they can be corrected in the objective if necessary. On the other hand, lateral color and coma must be corrected as well as possible. Most eyepieces have a large Petzval sum, which leads to a large amount of astigmatism at the edge of the field. ...
Get Lens Design Fundamentals, 2nd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.