1. The Refracting Telescope
Used to view very distant large object
Used to increase the angle subtended by the image.

2. Telescope Ray Diagram B θ1 u = ∞ fo fe L1 L2 Image at infinity h
Objective
Eyepiece θ2 θ1

3. Telescope Ray Diagram

4. Notes The objective forms a real inverted image
The eyepiece is used as a magnifying glass
Incoming rays are from far away and are parallel
The image is formed at the focal plane of the objective
The focal plane of the objective is also the focal plane of the eyepiece.

5. Magnification of the Telescope
The angular magnification of the telescope is given by:
Problem 25/p.623