Antlia Triband RGB Ultra II filter

Antlia Triband RGB Ultra Filter II

The Antlia Triband RGB Ultra Filter II is an evolution of the classic Triband RGB Ultra, now incorporating the H-beta line (486.1 nm) for more detailed imaging of nebulae. Designed to reduce light pollution, it is compatible with both color cameras (OSC) and monochrome sensors. Its optimized spectral design allows for imaging of deep-sky objects—including galaxies, reflection nebulae, star clusters, and emission nebulae, under skies ranging from Bortle 8 to Bortle 1, while delivering very natural-looking RGB images.

Applications and Performance

• Efficient capture of galaxies, reflection nebulae, star clusters and emission nebulae
• Balanced transmission to minimize color drift on broadband objects (stars, galaxies)
• Excellent halo control and improved signal-to-noise ratio thanks to refined surface treatment
• Can be used with fast lenses up to f/2 without any significant loss of efficiency or spectral shift
• Can be used as an alternative luminance filter for LRGB in mono imaging, except for dark nebulae (LDN)
• Can also be used for visual observation with large-aperture telescopes
• Targeted suppression of light pollution by effectively isolating Hα, OIII and blue spectra

Technical specifications

• Transmitted rays :
  • H-alpha (656.3nm)
  • NII (654.8nm and 658.3nm)
  • SII (671.6nm and 673.1nm)
  • OIII (495.9nm and 500.7nm)
  • H-beta (486.1nm)
• Maximum transmission: ＞92% for all main lines
• Out-of-band blocking: ≥OD4 from 300nm to 1050nm
• Filter thickness: 2mm ± 0.05mm
• Available size: 2″ mounted (M48x0.75)

Advantages of the Antlia Triband RGB Ultra II filter

• Wide RGB spectrum capture, suitable for both emitting and reflecting objects
• Improved contrast against a noisy background while preserving the natural color balance
• Perfect for projects requiring a simplified LRGB approach under heavy light pollution
• Compatible with virtually all lens setups, up to f/2
• Flexibility for color or monochrome cameras

Warnings

• Not designed for solar imaging
• Never use to observe the Sun directly. This would cause serious eye damage.