| 释义 |
Seidel theory Seidel theory[′zīd·əl ‚thē·ə·rē] (optics) A theory of aberrations in which the sine of the angle which a ray makes with the optical axis is approximated by the first two terms in the sine's Taylor expansion (the first- and third-order terms), rather than the first term alone, as in a first-order theory. |