what does the objective lens do on a microscope

The objective lens is a critical component of a microscope that captures and refracts the light reflected from an object, creating a focused and magnified image of the object being examined. It is located closest to the object being observed and is typically mounted on a rotating nosepiece or turret to enable easy selection. The objective lens is responsible for producing the base magnification needed to produce an image, and it determines the resolution power of the microscope. Each microscope objective is itself a complex assembly of lenses, and it can also provide optical aberration corrections. A typical microscope has three or four objective lenses with different magnifications, screwed into a circular "nosepiece" which may be rotated to select the required lens.