Astronomik OIII 6nm 1.25" (M28.5)
Key specifications
| Filter type | Narrowband |
|---|---|
| Passband | OIII 496 + 501nm |
| Bandwidth | 6 nm |
| Filter size | 1.25" |
| Mounted | Yes |
About
A 6 nm narrowband filter isolating the doubly-ionised oxygen lines at 496 and 501 nm, blocking sodium and mercury street lighting, airglow and most moonlight. The 6 nm width suits faint objects in crowded Milky Way fields, low dark-current cameras and heavily light-polluted sites. MFR coating, 1.25" M28.5 mount.