Optolong HSO / SHO 3 nm 2" (SKU: SHO-3nm-2 / SHO-3-2)

The Optolong SHO 3 nm 2" is a collection of three two-inch astronomical filters designed specifically for astrophotography using monochrome cameras or specially modified SLRs.

These narrowband filters, part of the HSO palette, enable photographers to capture breathtaking images of emission nebulae and remnants of supernova explosions. The filters' advanced production technology allows for extremely narrow passbands while maintaining high optical efficiency, resulting in images that resemble those captured by the Hubble Space Telescope. The Optolong SHO 3 nm 2" filters offer excellent transmittance for the Hα, S II, and O III lines, while effectively reducing light pollution from sodium and mercury lamps, making them ideal for photographing the sky near urban areas.

Each filter in the kit features a full multi-layer anti-glare coating applied using ion implantation techniques. These coatings not only provide exceptional optical performance but also ensure durability and resistance to scratches.

Key features of the Optolong SHO 3 nm 2" filter set include:

Half-width of only 3 nm for Hα, S II, and O III bands.

Full multi-layer coating that eliminates glare and protects against scratches.

Stable transmission band maxima regardless of ambient temperature changes.

Effective elimination of light pollution and skyglow effect.

Technical specifications:

• Filter type: HSO.
• Filter diameter: 2".
• Passband midpoint for the Hα line: 656.3 nm.
• Half bandwidth (FWHM) for the Hα line: 3 nm.
• Transmission for the Hα line band: 85%.
• Center of passband on S II line: 672 nm.
• Half bandwidth (FWHM) for the Hα line: 3 nm.
• Transmission for the Hα line band: 85%.
• Center of passband for O III line: 500 nm.
• Half bandwidth (FWHM) for O III line: 3 nm.
• Transmission for the Hα line band: 85%.
• Main blocked bands: Mercury lamps (435.8 nm, 546.1 nm, 577 nm, 578.1 nm), sodium lamps (598 nm, 589.6 nm, 615.4 nm, 616.1 nm).
• Anti-reflective coating: Full multi-layer coating (FMC).
• Frame material: Anodized aluminum.
• Frame color: Black.

The Optolong SHO 3 nm 2" filter set includes:

• Optolong Hα 2" filter.
• Optolong S II 2" filter.
• Optolong O III 2" filter.

The product is backed by a 24-month guarantee.