Chroma Narrowband Filters Ha, OIII and SII Filtersets with 5nm & 3nm F/3 optimised Bandwidth
These nebula filters from Chroma offer extreme contrast. Thus, the astrophotographer achieves a very good result even with considerable stray light from cities or from the moon. The high transmission is given up to a focal ratio of f/4.
The quality features of these narrow band filters
- High light transmission and narrow bandwidth to maximise contrast
- Use in light sensitive areas and dark locations
- Extends exposure time under moonlight conditions
- These narrow-band filters can be used up to f/4 with virtually no loss of signal.
- Blackened edges to prevent internal stray light reflections
- Consistent 3.0mm filter thickness ensures parfocality
H-Alpha Filters 5nm
H-alpha filters can only be used photographically, but objects emit about three times as much at this wavelength as they do at H-beta. H-alpha filters are essential for imaging nebulae and other objects which are rich in ionized hydrogen. At 656.3nm, a narrow-band emission filter is required to separate H-alpha from the SII doublet (671.6nm and 673.1nm).
OIII Filters 5nm
Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when imaging nebulae
SII-Filters 5nm
SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, at 671.6 and 673.1 nm. This filter also separates sulfur emission from H-alpha emission (656.3nm).
All transmission and blocking (OD) data are actual, measured spectra of representative production lots. Spectra varies slightly from lot to lot. Optical density values in excess of 6 may appear noisy because such evaluations push the resolution limit of low light level measurements.
Alternatively
Ha OIII SII -3nm -F/3
All transmission and blocking (OD) data are actual, measured spectra of representative production lots. Spectra varies slightly from lot to lot. Optical density values in excess of 6 may appear noisy because such evaluations push the resolution limit of low light level measurements.
