SV132 H-Beta 25nm Narrowband Filter for Visual Nebulae

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

• 2 inch metal mount with threading for 2 inch eyepieces
• Primary filter at 486 nm (blue) for nebulae
• Blocking of parasitic light to enhance contrast of nebulae
• 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
• Maximum transmission rate (T peak): 90%
• Blocking: OD3 @ 300-1100 nm
• Clear aperture: 44 mm
• Surface quality: 60/40
• Surface flatness: 1/4 λ
• Parallelism: 30"