Antlia Solar Discover Dualband ERF 2" (M48 thread)

Antlia Solar Discover Dualband ERF 2" (M48 thread)

Antlia Solar Discover Dualband ERF rejection filters are designed for combined use with H-Alpha and Calcium H and K filters. They are the perfect match for Antlia Filters' Solar Discover filter series, protecting their integrity when used on instruments over 100 mm in diameter or for certain special configurations, such as refraction instruments equipped with field correctors placed close to the focus.

These ERF filters completely block harmful ultraviolet and infrared frequencies and instead pass the frequencies of H-Alpha at 656.3 nm and the calcium doublet H and K at 396.8 and 393.3 nm, respectively.

Features at a glance

• FWHM of 25 nm centered on the wavelength of H-alpha at 656.3 nm with T＞95% transmission.
• FWHM of 25 nm centered on the Calcium K wavelength at 393.3 nm that also covers the Calcium K row at 393.3 nm with T＞90% transmission.
• Advanced multilayer optical treatment over a wavelength range from 200 nm to 1700 nm.
• Heat-resistant optical substrate with optical treatment applied on both faces.
• The 130 mm, 150 mm and 200 mm Antlia Solar Discover Dualband ERF filters are mounted in an adjustable cell for fitting on a variety of commercially available instruments.
• The 2'' Antlia ERF filter is a cell-mounted filter compatible with M48 threads.
• Transmitted wavefront correction: lambda/4 or better.

Specifications

Curva spettrale

Please note

• The Antlia Solar Discover Dualband ERF rejection filters cannot be used alone for observing the Sun. There must be an appropriate solar filter, H-Alpha or Calcium-H or Calcium-K, at the telescope focus, equipped with their necessary blocking filters, such as Antlia's Solar Discover series solar filters. Please contact us to verify the correct configuration.
• The 2" in-cell ERF filter cannot be used on instruments with free aperture over 100 mm. For larger diameters, larger rejection filters are recommended to be mounted at the front of the instrument.