Suppose you are using a telescope with a diameter of 22 cm (8.66 inches) and a focal length of 1650 mm (649.61 inches).
a. What is the f-ratio?
b. What eyepiece focal length will give you a magnification factor of 150?
The f-ratio is:
a) 3.33
b) 8.75
c) 75
d) 80