Astronomik OIII visual 1.25" (M28.5)
Key specifications
| Filter type | Narrowband |
|---|---|
| Passband | OIII 494-506nm |
| Bandwidth | 12 nm |
| Filter size | 1.25" |
| Mounted | Yes |
About
A visual OIII filter with a narrow 12 nm window over both oxygen lines, blocking sodium and mercury street lighting and airglow for a large contrast gain on gaseous and planetary nebulae and faint supernova remnants. Suits f/3.5 to f/15 and apertures from 6" up. 1.25" M28.5 mount.