Antlia LRGB Dark Series Set 2"

Antlia LRGB Dark Series Set 2"

Description
The Antlia LRGB Dark Series 2" filter set includes four filters: Luminance (UV/IR Cut), Red, Green and Blue. Each filter is made of high-quality quartz glass, selected for its outstanding thermal and mechanical stability due to its ultra-low thermal expansion. This material ensures consistent optical performance under varying environmental conditions, making it ideal for high-precision astrophotography.

The Luminance filter covers a wide spectrum from 390 nm to 710 nm, effectively cutting off UV and IR light. The Red, Green and Blue filters are tuned for maximum color separation and contrast while maintaining high transmission: up to 97% for Red and Green, and 95% for Blue.

The Dark Series features advanced multilayer coatings with out-of-band blocking rated at OD4.5 (0.005%), minimizing light leakage and reflections. Each filter is double-side polished to a uniform 2 mm ± 0.05 mm thickness, ensuring excellent parfocality. Unmounted versions are edge-blackened to eliminate stray light reflections.

These LRGB Dark Series filters are engineered to match Antlia’s SHO Ultra Narrowband filters (2.8 nm and 2.5 nm), as they share the same quartz substrate and refractive index. This improves parfocality between broadband and narrowband imaging.

The filters are mounted in ultra-thin black-anodized 2" (M48x0.75) aluminum rings, laser-engraved with filter information, compatible with standard filter wheels and holders.

Important note:
Even with parfocal filters, small focus shifts may occur during long sessions due to temperature changes affecting the optical path length. Manual or software-assisted focus checks are recommended every 1–2 hours, or more frequently if equipment is adjusting to ambient temperatures.

Technical specifications
• Transmission range – Luminance (UV/IR): 390 nm – 710 nm
• Transmission range – Red: 595 nm – 705 nm
• Transmission range – Green: 495 nm – 600 nm
• Transmission range – Blue: 400 nm – 505 nm
• Peak transmission: ≥ 97% (L, R, G); ≥ 95% (B)
• Out-of-band blocking: OD4.5 (0.005%)
• Filter thickness: 2 mm ± 0.05 mm
• Substrate: Double-side polished quartz glass
• Filter ring: 2" (M48 x 0.75), black anodized
• Laser-engraved identification
• Compatibility: All standard 2" filter wheels and holders

Additional information
• Designed for imaging only
• Ideal for mono or color cameras with filter wheels
• Fully compatible with Antlia SHO Ultra Narrowband filters
• Built with highest attention to spectral and mechanical precision