Draw a scale diagram of the optical component in a refracting telescope in normal adjustment, giving the components the following values in your diagram:
Objective lens focal length 12cm, diameter 6cm;
Single eyepiece lens focal length 2 cm, diameter 2cm.
Consider an object at infinity near the edge of the field of view but for which all light entering the objective will emerge from the eyepiece. Draw three rays (solid continuous lines) from this object; one through the centre and one through each edge of the objective, showing how they pass through the telescope and enter the observer’s eye, situated at the exit-pupil of the telescope. Any construction rays should be dotted. Fine the telescope’s magnifying power, its field of view, and the diameter of the exit-pupil.