Askar E2 (SII+OIII) 2-inch Ultra Duo-narrowband Filter Professional Astrophotography Tool for Deep-sky Imaging

Askar E2 (SII+OIII) 2-inch Ultra Duo-narrowband Filter Professional Astrophotography Tool for Deep-sky Imaging

Description:
- The Ultra E filter, as the name suggests, has the "Ultra" halo control capability. During the filter research and development process, we made a special design optimization for Ultra E. And in the end, it became a special filter with one bandwidth at 3nm and the other bandwidth outside 3nm.

- 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 ColourMagic Ultra E2 Duo-narrowband filter (OIII+SII) mentioned above.

- 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.

Specification:
- FWHM: SII:4.0nm±0.3nm/OIII: 3.7±0.3nm
- CWL: 500.7nm & 672nm
- Peak transmittance: 85%
- Thickness: 1.85 ± 0.05mm
- Barrier property: ≥OD5 at 200-1100nm
- Surface finish: 60/40
- Parallelism: 30″

Package Included:
- 1 x E2 Filter