Often a design calls for a given parameter to operate at a set of values, rather than at a constant value. For example, in a scanning system, the scanning mirror angle changes, whilst the rest of the optical system remains fixed.

Similarly, in a zoom lens fixed optical components are moved relative to each other to provide the zoom operation.

Virtually any parameter in ZEMAX, such as a wavelength, aperture value, field position, radius, thickness, glass type, or other data, may take on multiple values. Each configuration may have multiple values for a large number of different parameters. Configurations may be optimised for the same set of design goals, or for different design goals. This feature can be used to design conventional zoom lenses, scanning systems, multiple path systems, and has numerous other applications.

For the scanning system shown above,  optical performance, such as spot size, will vary across the scan. This can be seen as follows:

Spot at the centre of the scan

Spot at the edge of the scan

ZEMAX can optimise all configurations for the same, or different, design goals in each configuration simultaneously. For example, the designer may choose to optimise for the best spot size at all scan positions, or for the best spot size at the centre of the scan, sacrificing spot shape at the extreme scan positions.

This ability to automatically optimise optical systems over multiple configurations with multiple optimisation criteria is one of ZEMAX' most powerful features. It can even be used to athermalise optical systems by simultaneously optimising over a range of temperatures and pressures.

Muliple path systems include interferometers, lens arrays, and systems with beamsplitters. ZEMAX can draw all or one system configuration one one plot, either displaced or overlayed at any point. Global reference coordinates make it easy to link the locations of various components in the system to one another across configurations.