Antlia H-alpha 3 nm Pro 31 mm unmounted narrowband filter

Antlia H-alpha 3 nm Pro 31 mm is a professional astrophotographic filter transmitting red light with a wavelength of 656.3 nm emitted by ionized hydrogen atoms, the registration of which is particularly important when photographing emission nebulae.

Thanks to a very narrow half-bandwidth of only 3 nm, this filter combines the ability to almost completely eliminate the undesirable component from sodium and mercury lamps with high transmission efficiency for the Hα spectral line, one of the most important from the point of view of astrophotography.

Attention! The Hα filter is not recommended for visual observations.

The most important features of the filter are the Antlia H-alpha 3 nm Pro 31 mm filter

• bandpass filter made on high-quality Schott substrate with maximum transmission for radiation with a wavelength of 656.3 nm
• compatible with astrographs with light intensity reaching f / 3 (eg RASA or Hyperstar)
• extremely narrow half-width of the transmitted band (FWHM = 3 nm)
• equivalent optical density OD5 ensuring the efficiency of cutting out light pollution at the level of 99.999%

Technical specifications

• filter type: bandpass filter
• Filter diameter: 31 mm
• filter thickness: 2 ± 0.05 mm
• filter shape: round
• transmitted bands: Hα (656.3 nm)
• location of the maximum peak permeability (CWL): 656.3
• 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 (acc. To MIL-O-13830 standard): 60/40
• parallelism: 30 "
• the execution accuracy (RMS): λ / 4

Elements of the set

• Antlia H-alpha 3 nm Pro 31 mm filter

guarantee

3-year manufacturer's warranty (applies to delamination of the filter and substrate)

Product code: FILAST31HA3NM_ANT