What role does an objective lens serve in optical instruments?

The objective lens plays a crucial role in optical instruments, such as microscopes and telescopes, by forming the initial image closest to the observed object. This image is typically real and inverted, meaning that it is produced by converging light rays that originate from the object being observed. The purpose of the objective lens is to gather light from the object and create an intermediate image that can be further magnified by the eyepiece or any additional optics in the system.

This initial image is essential because it sets the stage for the subsequent steps in the optical process, where the eyepiece lens further magnifies the image for the viewer. The objective lens's ability to provide a clear, well-defined initial image is vital for the quality of the final view seen by the user. Thus, its primary function is to gather light effectively and form an accurate representation of the object being observed.