Definition:Central Projection

Definition

Central Projection of $\set {A, B}$ onto $\PP_2$ from $C$

Let $\PP_1$ and $\PP_2$ be planes.

Let $C$ be a fixed point which lies on neither $\PP_1$ nor $\PP_2$.

Let $S$ be a set of points on $\PP_1$.

For each point $x \in S$, let a straight line be constructed through $C$ and $x$ to intersect $\PP_2$ at $y$.

The set of all $y$ is called the central projection of $S$ onto $\PP_2$.

Let $f$ be a central projection of $S$ onto $\PP_2$.

The fixed point $C$ is called the center of projection of $f$.