Celestron 93624 Narrowband Oxygen III 2 Filter
The Celestron 93624 Narrowband Oxygen III 2-inch filter is a remarkable advance for the serious visual observer of emission nebulae. One of the biggest advantages of narrowband filters is that by passing only the light emitted by nebulae, light from artificial sources like street lights is blocked. This allows you to take detailed exposures of nebulas from a suburban location that can rival shots from much darker sites. The Celestron 93624 is made of high quality, solid plane parallel glass.