1.25" O-III Filter - 10 nm Narrowband
For extreme contrast enhancement when observing nebulae
The O-III filter is especially useful for planetary nebulae. In the [O III] line, they show their most interesting structures. But [O III] regions are also embedded in other gas nebulae. So an [O III] filter can show completely different details than a UHC filter or no filter.
The Baader [O III] filter is very narrow banded with only 10 nm FWHM. We recommend it for apertures above 200mm. Below, only low magnification is possible. It is a good addition to the broad band UHC-S filter from Baader.Baader [O III] filter transmission curve
The transmission curve shows a small 10 nm FWHM band - exactly on the [O III] line at 501 nm.
With the [O III] filter, even under worse stray light conditions in big cities, successful observations are possible. The background remains black also at big exit pupils.
The filter is dielectrically coated and aging-resistant, robust and scratch-proof. Highest image quality is guaranteed by plane-optically polished surfaces.Specifications:
- Plane-optically polished surfaces
- 10 nm FWHM band on the [O III] line at 501 nm
- 1.25" filter thread
- Aluminum cell
- Knurled edge
- Substrate 2 mm thick
Scope of delivery:
The O-III filter is especially useful for planetary nebulae. In the [O III] line, they show their most interesting structures.