Antlia H-alpha 3 nm Pro 1,25" narrowband filter

The Antlia H-alpha 3 nm Pro 1.25" is a specialized astrophotography filter designed to capture the red light emitted at a precise wavelength of 656.3 nm by ionized hydrogen atoms, a crucial element when photographing emission nebulae.

This filter boasts an incredibly narrow half-bandwidth of just 3 nm, making it exceptional at filtering out unwanted light from sources like sodium and mercury lamps while ensuring high transmission for the Hα spectral line. This spectral line is of paramount importance in astrophotography.

Please note that the Hα filter is not recommended for visual observations.

Key Features of the Antlia H-alpha 3 nm Pro 1.25" Filter:

• It is a bandpass filter crafted on a high-quality Schott substrate, optimized for maximum transmission of 656.3 nm radiation.
• It is compatible with astrographs capable of handling light intensities down to f/3, such as the RASA or Hyperstar.
• It offers an exceptionally narrow half-width of the transmitted band (FWHM = 3 nm).
• It provides an equivalent optical density (OD5), ensuring effective elimination of light pollution at a remarkable 99.999% level.

Technical Specifications:

Filter Type: Bandpass Filter

Filter Diameter: 1.25"

Filter Thickness: 2 ± 0.05 mm

Filter Shape: Round

Transmitted Bands: Hα (656.3 nm)

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)

Light Pollution Blocking Efficiency: > 99.999%

Equivalent Optical Density for Blocked Lines: OD5 (300 - 1000 nm)

Surface Quality Index (per MIL-O-13830 standard): 60/40

Parallelism: 30"

Execution Accuracy (RMS): λ / 4

Kit Components:

• Antlia H-alpha 3 nm Pro 1.25" Filter

Warranty:

The product comes with a 3-year manufacturer's warranty, covering issues related to delamination of the filter and substrate.