Filtre à bande étroite SV132 H-Beta 25nm for visual nebulosity

This narrowband filter is specifically designed to enhance the visibility of nebulae, such as the Horsehead Nebula and the Cocoon Nebula, in dark skies.

Features

• Metal mount 2 inches with threading for 2-inch eyepieces
• Main filter at 486 nm (blue) for nebulae
• Filtering of stray light to improve nebula contrast
• Optimal use with a large aperture telescope

Technical specifications

• Model: SV132
• Type: H-Beta
• Size: 2 inches
• Material: B270
• Substrate thickness: 1.85 mm
• Wavelength range: 400-700 nm
• Central wavelength (CWL): 486 nm ± 2 nm
• Full width at half maximum (FWHM): 25 nm ± 2 nm
• Peak transmission rate (T peak): 90 %
• Blocking: OD3 @ 300-1100 nm
• Clear aperture: 44 mm
• Surface quality: 60/40
• Surface parallelism: 1/4 λ
• Parallelism: 30"