Multi Mag optics represent the ideal answer to many non-contact machine vision applications that require different optical magnifications to check geometrically complex parts at various levels of detail, maximizing measurement accuracy.
Fixed magnification telecentric lenses are an excellent choice for accurate measurement but may not be flexible enough to inspect very small features on larger samples; Moreover, if you need to accurately measure multiple sized objects (for example a set of screws), two or more fixed lenses would be needed to get the best image for each format.
Standard zoom lenses may be a good alternative, often trading convenience for modest results in terms of accuracy and repeatability. Moreover, infinite conjugate lenses like photographic equipment optics will not properly work when used to observe objects from up close.