Which term describes a lens that gathers light from an object and forms a real image?

• A. Objective
• B. Eyepiece
• C. Reflecting telescope
• D. Microscope

Answer: (A)

In optical instruments, the lens that gathers light from the object and forms the first real image is the objective lens. It sits at the front of a telescope and collects light from distant objects, creating a real image at its focal plane. That real image is then magnified by the eyepiece for viewing. The eyepiece only magnifies a pre-formed image, not create the initial real image. A reflecting telescope uses mirrors, not a lens, and a microscope, while it also uses lenses, is a different instrument with a different setup. So the term that best fits is the objective.