# Ray diagrams

"A-rre, they're diagrams" - Issac Newton

# Some basic terminology

• Object - The thing that's emitting light (whether reflecting or producing, doesn't make a difference)

• Image - A visual representation of an object; where light rays bounce of/are produced from the object, and they converge at a point (that's where the image is formed)

• Center of curvature - If a spherical mirror were part of a sphere, then the center of the sphere would be center of curvature.

• Focus - The point where the parallel light rays converge to form the image. If the aperture (see below) is too big, then the light rays will not converge at a single point, resulting in a distorted image

• Pole - The Point inline with focus and center of curvature, at the center of the mirror

• Radius of curvature - The distance between the Pole and center of curvature, equal to the radius of the sphere. This distance is always $2f$, that is, two times the focal length. This means that the focus lies exactly between the center of curvature and Pole