Objectives

Objectives are the lens assemblies at the business end of a microscope, the component that gathers light from the specimen and forms the magnified image the eyepiece or camera then relays. An objective is defined by three numbers engraved on its barrel: magnification, numerical aperture, which sets resolving power and light collection, and the tube length or infinity marking it was computed for. The Questpair catalogue holds 272 objective listings from 10 verified suppliers across 5 countries, offered new, used and refurbished for laboratory microscopy. Of those, 98 percent of the listings are used. Prices range from EUR 40 to EUR 23.500, a spread that separates a single achromat from a complete apochromatic set.