Askar Filters Colour Magic SII 3nm 2" (87815)

The ColourMagic 3 nm Narrowband Filter features an extremely narrow bandwidth combined with excellent light transmission, allowing the capture of high-contrast, low-noise deep-sky images even in locations affected by urban light pollution, atmospheric airglow, or other unwanted light sources.

This performance makes faint nebular structures and subtle stellar details, which are often difficult to detect, clearly visible. In addition, the ColourMagic filter incorporates an optimized optical design for effective halo control, ensuring higher image quality and enhancing the overall expressive power of astrophotography.

SII filter characteristics
The narrowband SII filter allows light from ionized sulfur atoms at wavelengths of 671.7 and 673.1 nanometres to pass through. These emission lines are characteristic of many planetary nebulae, emission nebulae, and supernova remnants, enabling these objects to stand out clearly against the background sky.

Astrophotography use
This filter is best suited for use with monochrome cameras. For optimal results, images captured with the SII filter should be combined with exposures taken using OIII and H-alpha filters. This combination reveals delicate nebular structures with excellent contrast and detail.

Specifications

• Quantity: 1 piece

• Central wavelength: 672 nm

• Half-value bandwidth: 3.7 nm

• Filter thickness: 1.85 mm

• Mount size: 2-inch

• Transmission: 85%

• Mount material: Aluminium

• Optical coating: Multi-layer

General information

• Type: Filter

• Design: Narrowband line filter

• Series: Colour Magic 3 nm

• Connection to telescope: 2-inch

Areas of application

• Suitable for photography: Yes

• Suitable for visual observation: No

• Twin stars: No

• Moon and planets: No

• Nebulae and galaxies: Yes