Askar ColourMagic Ultra 2" Duo-Band E2 Filter - SII + OIII - CM-DUO-E2

Designed for deep-sky imaging with color astro cameras, the Askar ColourMagic Ultra E2 filter, as the name suggests, includes "Ultra" halo control capability. 

When shooting deep-sky galaxies with colour cameras, a duo-narrowband filter in the Hα and OⅢ bands is often used; whereas with a mono camera, a narrowband filter in the Hα, SⅡ and OⅢ bands is often used, leaving users with colour cameras missing one band of nebula detail. This can be compensated by using the ColourMagic Ultra E2 Duo-narrowband filter (OⅢ+SⅡ).

The Askar ColourMagic Ultra E2 Duo-narrowband filter (OⅢ+SⅡ) has an ultra-high transmittance of over 85% at its center wavelength (500.7nm and 672nm). It can effectively enhance the contrast of your pictures, making it easier to display the details of the stars that otherwise are fairly difficult to spot. In areas with very serious light pollution, this filter can also selectively filter light pollution and cluttered signals through the emission lights of the nebula to achieve the ideal shooting effect.

ColourMagic E2 Ultra Duo-Band Filter Specifications

FWHM:  SII = 4.0 +/- 0.3nm, OIII = 3.7nm+/- 0.3nm

CWL:  500.7nm & 672nm

Peak Transmittance:  85%

Filter Thickness:  1.85 +/- 0.05mm

Barrier Property:  ≥OD5 @ 200-1000nm

Surface Finish:  60/40

Parallelism: 30"