Dual-Band 7nm Nebula Filter for Astrophotography SVBONY 2 inches

This narrowband filter specifically designed for astrophotography allows you to capture color images even in heavily light-polluted urban environments. It is particularly useful for photographing emission nebulae, planetary nebulae, and supernova remnants.

Features

• Size: 1.25 inches (31.75 mm)
• Substrate thickness: 1.85 mm
• Clear aperture: 26 mm
• Wavelength range: 300-1100 nm
• FWHM (OIII and HA): 7 nm
• Blocking: >OD5
• Maximum transmittance: 500.7 nm @ T>90%, 656.3 nm @ T>94%
• Surface quality: 60/40
• Surface parallelism: 1/4λ

This filter is designed to eliminate interference caused by artificial light from sodium or mercury street lamps, as well as other unwanted disturbances like skyglow.