Astronomik H-Alpha CCD Filter, 12 nm, Clip-Filter EOS XL
This H-alpha Filter is suitable for imaging of Hydrogen nebulas from observation sites with light pollution and from dark sites as well. The contrast between an object glowing at 656nm and the background is increased enormous!
Due to the combination of the narrow bandwidth of 6nm and the high transmission of typically 96% the filter gives you an enormous contrast boost, as all unwanted light from other wavelengths than 656nm is blocked form UV up to the IR. This results in an extremly dark background.
The FWHM of 6nm is matched to give you optimal performance with CCD and CMOS sensors with a very low dark current! The 6nm filter is the best choice if you are observing from a heavily light polluted site or if you are imaging faint objects in starcrowded regions of the milkyway.
Due to the new MFR coating technique you may use one single filter on all instruments up to f/4 without a significant reduction in performance.
Der Astronomik H-alpha filter MUST NOT BE USED for solar observation!
Products specifications
| Typical Transmission at the H-alpha Line (656 nm) | 96% |
| Full-Width-Half Maximum (FWHM) | 12nm |
| Guaranteed Transmission at the H-alpha Line (656 nm) | >90% |
| perfect blocking of unwanted light | from UV up to the IR |
| parfokal with all Astronomik filters | Yes |
| Coating technique | MFR |
| Thickness | 1mm |
| Usable with all optics up to | up to f/3 |
| Filter thread / size | Clip-Filter EOS XL |
