Which map projection variant has projection lines that emanate from infinity?

• A. Orthographic
• B. Gnomonic
• C. Mercator
• D. Cylindrical

Answer: (A)

Projection lines emanating from infinity correspond to a parallel projection, where all lines of sight are parallel and perpendicular to the projection plane. This is what happens in the orthographic projection: imagine viewing the globe from infinitely far away—the rays of projection are parallel, so the map represents the hemisphere facing you with a view akin to a distant, space-based photograph. That’s why projection lines originate effectively at infinity in this case.

In contrast, other common variants use lines that come from a finite point, such as the sphere’s center, so the lines converge toward that center rather than running parallel. This is why they don’t have projection lines from infinity.