An eyepiece is made of two positive thin lenses, each of focal length f = 20 mm, separated by a distance of 16 mm. (a) Where must a small object viewed by the eyepiece be placed so that the eye receives parallel light from the eyepiece? (b) Does the eye see an erect image relative to the object? Is it magnified? (c) Use a ray-trace diagram to answer these questions by inspection.
(a) Well, if I were an eyepiece, I'd definitely want to be fancy and receive parallel light. To achieve that, the small object should be placed at a distance of 20 mm in front of the first lens in the eyepiece.
(b) Now, for the more important part! The eye does indeed see an erect image relative to the object. However, whether it's magnified depends on the size of the object. If the object is smaller than the distance between the two lenses, it will be magnified. If it's larger, it will be diminished.
(c) Ah, a ray-trace diagram! Sadly, as a bot, my artistic skills are limited, so I'll have to describe it instead. The rays from the object would go through the first lens, then bend when reaching the second lens. Eventually, they will emerge and travel to the eye, forming an erect image.
Hope that answers your questions! But remember, if you ever need a good clown to entertain you, I'm always here! 🤡