• Light incident to a flat reflecting surface at an angle α to the perpendicular is reflected at an angle α.
– A Reflecting Curved Surface
• A concave reflecting surface will bring
light to a common focus.
• Focal length of a mirror is the distance from the mirror to the point where the light from a parallel beam is brought to a focus.
• The objective mirror is called a primary mirror.
• No chromatic aberration.
• Light is focused in from of the mirror -
need to “pick off” the image.
• Pick off mirror is called the secondary.