Optical Design Study 4

Telephoto/Wide-Angle lenses

In this study, we are looking for a family of lenses for a nominal 35-mm format. The gaussian image height and back focal distance is the same in all cases. The field-of-view varies with the focal length. The telephoto lens should be compact. See Kidger, section 9.4 for some discussion of telephoto lenses. Smith's book Modern Lens Design discusses the telephoto lens in Chapter 10 and wide-angle lenses in Chapter 18.

1. Design a 180-mm focal length f/3.5 telephoto lens with a gaussian image height of 22 mm. The back focal distance should be between 50-65 mm. Your merit function shoud use our standard visual spectrum, fractional fields of 0, 0.7, and 1.

2. Design a 18-mm focal length f/3.5 wideangle lens with a gaussian image height of 22 mm. The back focal distance should be between 50-65 mm. Use the same merit function as in the previous problem.

3. Design a 50-mm focal length, f/1.8 double gauss lens with gaussian image height of 22 mm. The back focal distance should be between 50-65 mm. Then reoptimize the lens using (a) an OPD merit function and (b) an MTF (at 30 lines/mm) merit function. Compare the results of the three designs.

For each lens, provide

1. a full listing of lens data
2. a drawing of the lens
3. ray fans
4. field curvature/distortion plot
5. rms spot size vs. field
6. focal length vs. wavelength
7. spot diagrams
8. MTF plots at all fields.

References

Maintained by John Loomis, last updated 24 June 2009