Antlia SII 3 nm Pro 36 mm Unmounted Narrowband Filter

The Antlia SII 3 nm Pro 36 mm filter is a professional-grade astrophotographic filter designed specifically to capture the wavelength of 671.6 nm emitted by double ionized sulfur atoms. It is an essential tool for photographing emission nebulae, allowing you to capture the mesmerizing beauty of the cosmos.

Crafted with meticulous attention to detail, the Antlia SII filter is manufactured to the highest standards. Rigorous surface quality tests, conducted in accordance with stringent military standards, guarantee its exceptional performance. This filter boasts a remarkably narrow half-band width of only 3 nm, enabling it to effectively eliminate unwanted components from sodium and mercury lamps while maintaining high transmission for the crucial SII spectral line—making it indispensable for astrophotography enthusiasts.

It is important to note that the SII filter is not suitable for visual observation and should never be used for solar observation. Its purpose is solely for astrophotography.

Key Features of the Antlia SII 3 nm Pro 36 mm Filter:

Bandpass Filter: Built on a high-quality Schott substrate, this filter maximizes the transmission of radiation at a wavelength of 671.6 nm.

Compatibility: Designed to be compatible with astrographs that have a high light intensity of up to f/3, such as RASA or Hyperstar.

Ultra-Narrow Half-Width: With a full width at half maximum (FWHM) of only 3 nm, this filter ensures maximum contrast for your astrophotography.

Optical Density: Boasting an equivalent optical density of OD5, the filter effectively cuts out light pollution at an impressive level of 99.999%.

Technical Specifications:

• Filter Type: Bandpass Filter
• Filter Diameter: 36 mm
• Filter Thickness: 2 ± 0.05 mm
• Filter Shape: Round
• Transmitted Bands: SII (671.6 nm)
• Peak Transmittance (CWL): 671.6 nm
• Half Bandwidth (FWHM): 3 nm
• Maximum Transmission: > 88%
• 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)
• Light Pollution Blocking Efficiency: > 99.999%
• Equivalent Optical Density for Blocked Lines: OD5 (300 - 1000 nm)
• Surface Quality Index (according to MIL-O-13830 standard): 60/40
• Parallelism: 30"
• Execution Accuracy (RMS): λ/4

Included in the Set:

• Antlia SII 3 nm Pro 36 mm Filter

Guarantee:

The Antlia SII 3 nm Pro 36 mm Filter comes with a 3-year manufacturer's warranty, covering any delamination of the filter and substrate. This warranty ensures your peace of mind and underscores the confidence we have in the quality of our product.