Coma is a monochromatic lens defect that occurs when light enters the optic at an angle, causing the rays passing through the edges of the lens to focus at different points than those passing through the center. This results in point sources, such as distant streetlights or projected pinholes, smearing into a characteristic V-shape or teardrop tail near the edges of the field of view.
Heard on the job
The new projection lens is sharp in the center, but the coma at the edges makes the gobos look smeared.
Also heard as
- comatic aberration