Orthoscopic doublet lenses are known to minimize which type of spherical aberration?

Orthoscopic doublet lenses are known to minimize which type of spherical aberration?

• A. Distortion
• B. Longitudinal spherical aberration
• C. Coma
• D. Radial astigmatism

Answer: (A)

Orthoscopic doublets are designed to reproduce images with minimal distortion across the field. Distortion is a geometric error that affects how straight lines are mapped, not a spherical aberration. Spherical aberration comes in different flavors, and an optimized doublet can be set up so that the focal points for paraxial and marginal rays align more closely along the optical axis. The specific spherical aberration that such a design can reduce most effectively is longitudinal spherical aberration, where rays at different distances from the axis focus at different points along the axis. Coma and radial astigmatism are off-axis aberrations and aren’t the primary targets of this particular lens arrangement. Distortion isn’t a spherical aberration, so it isn’t the type being addressed when we talk about spherical aberration. So, the type of spherical aberration minimized by an orthoscopic doublet, in that context, is longitudinal spherical aberration.

Orthoscopic doublets are designed to reproduce images with minimal distortion across the field. Distortion is a geometric error that affects how straight lines are mapped, not a spherical aberration.

Spherical aberration comes in different flavors, and an optimized doublet can be set up so that the focal points for paraxial and marginal rays align more closely along the optical axis. The specific spherical aberration that such a design can reduce most effectively is longitudinal spherical aberration, where rays at different distances from the axis focus at different points along the axis.

Coma and radial astigmatism are off-axis aberrations and aren’t the primary targets of this particular lens arrangement. Distortion isn’t a spherical aberration, so it isn’t the type being addressed when we talk about spherical aberration.

So, the type of spherical aberration minimized by an orthoscopic doublet, in that context, is longitudinal spherical aberration.