OIII filters: only pass light at 501 nanometers wavelength. This corresponds to the spectral line of the doubly ionized oxygen . This line is emitted by planetary nebulae and some emission nebula, so that by means of this filter these objects remain visible while the rest is hidden. This effect increases contrast and makes faint fog visible.
The particularly narrow-band filter: is ideal for fast optical system up to f / 3.5 . Since even slower optics up to f / 8 handle this filter very well, it can be described as very versatile.
Features
Specifications
Kit content
Baader Ultra-Narrowband 4.5nm O III CCD-Filter 2" (with LPFC)
User guide