Antlia SII 3 nm Pro 50 mm unmounted narrowband filter

Antlia SII 3 nm Pro 50 mm Unmounted Astrophotography Narrowband Filter

The Antlia SII 3 nm Pro 50 mm is a premium astrophotographic filter meticulously engineered for capturing stunning images of emission nebulae. This professional-grade filter is adept at transmitting light at a precise wavelength of 671.6 nm, emitted by double-ionized sulfur atoms, making it an indispensable tool for astrophotographers aiming to achieve exceptional detail and contrast.

Each Antlia SII filter is crafted with a commitment to excellence, undergoing rigorous surface quality assessments that conform to stringent military standards. The result is a filter that promises outstanding performance and reliability. Its ultra-narrow half-band width of just 3 nm effectively suppresses unwanted interference from sodium and mercury lamps, while ensuring high transmission of the critical SII spectral line.

Important Note: The SII filter is not intended for visual observation and should never be used as a solar filter.

Key Features of the Antlia SII 3 nm Pro 50 mm Filter:

• Bandpass Filter: Constructed using high-quality Schott substrate to maximize transmission at 671.6 nm.
• Compatibility: Ideal for astrographs with high light intensity, such as those with f/3 aperture ratios (e.g., RASA or Hyperstar).
• Ultra-Narrow Bandwidth: Features a half-width of 3 nm (FWHM) for superior contrast in astrophotography.
• Efficient Light Pollution Reduction: Achieves a light pollution blocking efficiency of 99.999% with an equivalent optical density (OD5).

Precise Technical Specifications:

• Filter Type: Bandpass filter
• Filter Diameter: 50 mm
• Filter Thickness: 3 ± 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 (MIL-O-13830 standard): 60/40
• Parallelism: 30 arc-seconds
• Execution Accuracy (RMS): λ/4

Included in the Set:

• Antlia SII 3 nm Pro 50 mm filter

Warranty:

This filter is supported by a 3-year manufacturer's warranty, covering delamination of the filter and substrate, ensuring peace of mind for your astrophotographic pursuits.