IRlens glasses

Coma, so called because a point image is blurred into a comet shape, is produced when rays from an off-axis object point are imaged by different zones of the lens. In spherical aberration, the images of an on-axis object point that fall on a plane…

Infrared lens material

The S2 term in the OPD expression represents the aberration called coma, in which the image of a point has the appearance of a comet. The x′ and y′ components are as follows:

Another aberration, called coma, makes image points near the edges of the film appear as irregular, unsharp shapes. Distortion is present when straight lines running parallel with the picture edges appear to bow outward (barrel distortion) or inward (pincushion distortion).