The Schneider 138mm +2 Split-Field Diopter Lens shortens the close-focusing distance of normal fixed focal length or zoom lenses. This allows the camera to focus closer to the subject and achieve a larger image size while bringing out the sharpest details in even the tiniest subjects.
A “magnifying glass” for lenses to subtly decrease lens minimum focus distance to achieve results similar to macro lenses by achieving closer focus and shallower depth of field. The Split-Field Close-Ups Diopters affect only half of the field of view and therefore allow for more of the scene to be in total focus simultaneously.
The diopter will prevent the ability to focus the lens to infinity and will results in focus shift when used with zoom lenses.