In real optical systems, image quality is often limited not by diffraction alone but by optical aberrations arising from lens geometry, alignment, and field dependence.
Among third-order Seidel aberrations, coma aberration plays a crucial role in degrading off-axis image quality, producing comet-shaped blur patterns that are especially noticeable in imaging, astronomy, and automotive vision systems.
Modern optical design tools such as Ansys Zemax OpticStudio allow engineers to quantify, visualize, and perform efficient coma aberration correction during the design stage —reducing costly physical iterations.
Coma is an aberration affecting off-axis object points, where rays passing through different zones of a lens fail to converge at a single image point.
Zemax allows rapid evaluation of:
Refer below example wherein a plano convex lens’s performance is evaluated with aperture stop being on left side of the lens & with aperture stop being on right side:
Observe the geo radius values for off-axis field spot, you can see that spot size as well as coma spread is less of OS 2 optical system compared to OS 1 despite having the same configurations & start design, OS 2’s lens curvatures were optimized a bit more.
Without simulation, coma correction requires trial-and-error prototyping.
Coma aberration is one of the most important factors affecting off-axis image quality in wide-field optical systems. Its presence can significantly degrade resolution and introduce distortions that impact applications ranging from astronomy to machine vision and automotive sensing.
Mastering these techniques allows optical designers to achieve high image quality across the entire field of view while reducing development time and minimizing the need for physical prototyping.
