How to use a Split Focus Diopter | Shanks FX | PBS Digital Studios
A split focus diopter is a unique way to achieve the illusion of deep focus. The half convex glass attaches in front of the camera’s lens to make half the lens nearsighted.
Before the digital age of cinema, many directors made frequent use of the split-focus diopter.
The split diopter allowed directors to capture two main focal points in just one shot, rather than having to shoot two different angles.