Astronomik O-III Narrowband Filter for 1,25'' The Astronomik O-III filter is made for visual observing of gas nebulas and planetary nebulas. The transmission is very narrow, more than the UHC filter. By that it results in a much higher contrast. Especially at Super Novae like the Cirrus Nebula or Planetary Nebulas the more in contrast may be crucial for seeing or not.
Which objects could be observed:This filter enables you to observe Super Novae or Planetary Nebulas with a much higher contrast.
For which telescope this filter can be used: We recommend the O-III filter for telescopes from 150 mm aperture onwards. With smaller telescopes you won´t have enough light. Here it´s better to use the UHC or UHC-E. From 25 cm aperture onwards most star observer prefers the O-III over the UHC.
Delivery contains: Products specifications
| Connectingthread | M 28.5 mm both sides |
| Diameter | 1 1/4" |
| Accessory | Filterbox |
| Type of filter | OIII Filter |
| Transmission | near 100 % in both OIII Wavelength |
| Made for | Visual Observing with Telescopes from 150 mm onwards |
