Antlia S-II 2" 4,5 nm EDGE

Antlia S-II 2" 4.5 nm EDGE is a professional astrophotographic filter with a half-transmittance window width (FWHM) of 4.5 nm. It transmits light with a wavelength of 671.6 nm emitted by doubly ionized sulfur atoms, the registration of which is particularly important when photographing emission nebulae.

This filter combines the ability to almost completely eliminate the unwanted component coming from sodium and mercury lamps with high transmittance for the S-II spectral line, one of the most important from the point of view of astrophotography . It was made on a high-quality glass substrate, minimizing the risk of internal light reflections.

Antlia S-II 2" 4.5 nm EDGE is characterized by a steep slope of the permeability window and unlike ordinary broadband filters, it does not show a significant decrease in transmittance resulting from the shift of the maximum permeability peak (CWL). This means that the Antlia 4.5nm EDGE family of filters will work perfectly with telescopes with a wide range of light intensity.According to the manufacturer, the results of the analysis of the violet shift confirm that these filters can be use in optical systems with a maximum light power of f/3.

Attention! The S-II filter is not recommended for visual observation or solar observation.

Highlights of the Antlia S-II 2" 4.5 nm EDGE filter

• band-pass filter made on a high-quality optical substrate with maximum transmission for radiation with a wavelength of 671.6 nm
• compatible with astrographs with light intensity up to f/3 with minimal signal loss
• half bandwidth of transmission (FWHM) of 4.5 nm
• optical density equivalent OD5 guaranteeing high efficiency of light pollution removal

Technical parameters

• filter type: bandpass filter
• Filter diameter: 2"
• filter thickness: 2 ± 0.05 mm
• filter shape: round
• pass bands: S-II (671.6 nm)
• location of the peak of transmittance (CWL): 671.6 nm
• half bandwidth (FWHM): 4.5 nm
• maximum transmission: >90% ± 1 nm from the maximum transmission peak
• blocked light pollution 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)
• optical density equivalent for blocked lines: OD5 (300 - 1000 nm)
• surface quality index (according to MIL-O-13830): 60/40
• parallelism: 30"
• manufacturing accuracy (RMS): λ/4
• holder thread: M48x0.75

Set elements

• Antlia S-II 2" 4.5 nm EDGE filter

Guarantee

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

Product code: FILAST2SII4,5NM_ANT