How de-focusing makes wavefront errors more apparentТЖ
The model beams with various amount of defocus for a telescope with moderate coma and the error beam for that focus setting, that is the difference between the model beam and the model beam for a perfect (no coma) telescope.
| Defocus | Beam | Error beam |
|---|---|---|
| None |  |
 |
| 1 rad |  |
 |
| 2 rad |  |
 |
| 5 rad |  |
 |