Askar Colour Magic 6nm Ha/OIII Duo Band D1 Filter - 2 inch

The 6nm Color Magic Duo Band has high Ha and OIII transmission and is ideal for narrow band imaging with color cameras.

The Askar 6nm Duo-narrowband Filter (OIII & Ha) has ultra-high transmittance over 90% at its center wavelength (500.7nm and 656.3nm) and can effectively eliminate the influence of light pollution.

Even in locations seriously affected by light pollution, images taken with the Askar 6nm Duo-narrowband Filter are still of very high quality. 

The Askar 6nm Duo-narrowband Filter (OIII & Ha) is ideal for photographing emission nebulae, planetary nebulae or supernova remnants.

The narrow bandwidth of the filter effectively blocks out the effects of light pollution or other distracting factors such as night glow.

Currently available as a 2" mounted filter (other sizes planned).

Specifications

• 6nm Duo-narrowband Filter (OIII & Ha) 2"
• FWHM: 6nm
• CWL: 500.7nm & 656.3nm
• Peak transmittance: 90%
• Thickness: 1.85 ± 0.05mm
• Barrier property: ≥OD5 @ 200-1100nm
• Surface finish: 60/40
• Parallelism: 30"

Further Notes

Askar has designed this Ha+OIII Dual Band filter (D1) to be especially suitable for use with their Duo Band SII+OIII filter (D2)

When shooting data through both dual band filters (Duo Band SII+OIII and Duo Band Ha+OIII filter) and a color camera, users will have remarkable results.

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, and after image processing, it can achieve an excellent result which is almost as good as shooting with a combination of three narrowband filters and mono camera.

Askar have named the Hα+OIII 2" 6nm duo-narrowband filter "D1" and the SII+OIII filter "D2". They are now available as a set in 2" Mounted format only.