Askar's newly launched ColourMagic Super D 2" Duo-narrowband filters are specifically designed for deep-sky imaging.
As the name suggests, the Super D filters have "Super" halo control.
During the filter research and development, Askar made a 'special design optimisation' for Super D filters.
The filters provide one bandwidth at 6nm and the other outside 6nm.
FWHM: OIII 6.5nm ±0.5nm / SII 8.5nm ±0.5nm
CWL: 500.7nm & 672nm
Peak transmittance: 85%
Thickness: 1.85 ± 0.05mm
Barrier property: ≥OD5 @ 200-1100nm
Surface finish: 60/40
Users will have remarkable results When shooting data through dual-band filters (D1 and D2) and a colour camera.
Usually, in astrophotography, the Hα signal-to-noise ratio is stronger, while the OIII is relatively weak. As our two duo-narrowband filters are Hα+OIII and SII+OIII, the combination can balance the signal-to-noise ratio of each channel when shooting data. After image processing, it can achieve an excellent result, almost as good as shooting with a combination of three narrowband filters and a mono camera.
Here is a link detailing how to process D1 and D2 Data in Pixinsight.