Fundamental Optics

Performance Factors

After paraxial formulas have been used to select values for component focal length(s) and diameter(s), it is time to select actual lenses. As in any engineering problem, this selection process involves a number of tradeoffs, including performance, cost, weight, and environmental factors.

Diffraction  Aberrations  Lens Shape

The performance of real optical systems is limited by several factors, including lens aberrations and light diffraction. The magnitude of these effects can be calculated with relative ease. Numerous other factors, including lens manufacturing tolerances and component alignment, also impact the performance of an optical system. Although these are not considered explicitly in the following discussion, it should be kept in mind that if calculations indicate that a lens system only just meets the desired performance criteria, in practice it may fall short of this performance as a result of other factors. In critical applications, it is generally better to select a lens whose calculated performance is significantly better than needed.

Back to Top

Previous    Next

Optics Guide Copyright 2002 Melles Griot Inc.