Antlia H-Alpha 3 nm Pro 50 mm Unmounted Narrowband Filter

Antlia H-alpha 3 nm Pro 50 mm Professional-Grade Astrophotographic Narrowband Filter

The Antlia H-alpha 3 nm Pro 50 mm is a top-tier, professional astrophotographic filter crafted for capturing the striking red light emitted by ionized hydrogen atoms. This filter is indispensable for photographing emission nebulae, as it focuses on a critical wavelength of 656.3 nm.

What truly distinguishes this filter is its exceptionally narrow half-bandwidth of just 3 nm. This precision allows it to effectively block unwanted light from sodium and mercury lamps, while ensuring high transmission efficiency of the crucial Hα spectral line, a cornerstone in astrophotography.

Note: This Hα filter is not recommended for visual observations.

Key Features:

• Constructed with a high-quality Schott substrate, ensuring maximum transmission for 656.3 nm radiation.
• Compatible with astrographs featuring a light intensity as low as f/3, including RASA and Hyperstar models.
• Boasts an incredibly narrow half-width of the transmitted band (FWHM = 3 nm).
• Features an optical density of OD5, providing 99.999% efficiency in filtering out light pollution.

Technical Specifications:

• Filter Type: Bandpass Filter
• Filter Diameter: 50 mm
• Filter Thickness: 3 ± 0.05 mm
• Filter Shape: Round
• Transmitted Bands: Hα (656.3 nm)
• Location of Maximum Peak Permeability (CWL): 656.3 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)
• Efficiency in Blocking Light Pollution: > 99.999%
• Equivalent Optical Density for Blocked Lines: OD5 (300 - 1000 nm)
• Surface Quality Index (MIL-O-13830 standard): 60/40
• Parallelism: 30"
• Execution Accuracy (RMS): λ/4

Set Components:

• Antlia H-alpha 3 nm Pro 50 mm Filter

Warranty:

This filter comes with a comprehensive 3-year manufacturer's warranty, covering delamination of the filter and substrate.