At what distance from the objective lens in a refracting telescope is the primary image formed-that is, at what distance would a person place photographic film if one wanted to take a photograph?
A) its focal length
B) its diameter
C) twice its focal length
D) immediately behind the lens to collect the most light

Question

Quizplus · Accepted Answer

The primary image in a refracting telescope is formed at the focal length of the objective lens. This is the point where parallel rays of light (assuming they're coming from a distant object) are brought to focus, forming a clear image.

At What Distance from the Objective Lens in a Refracting