Antlia LRGB-V Pro Series 50 mm Unmounted Filter Set

Description

The Antlia LRGB-V Pro Series 50 mm unmounted filter set is designed for astrophotography with monochrome cameras using CCD and CMOS sensors. Antlia specifically lists KAF and KAI sensors, Sony IMX, GSENSE and other similar sensor families as suitable for these filters.

The set includes four filters: Luminance, Red, Green and Blue. The Luminance filter is a colourless UV and IR blocking filter.

The LRGB-V Pro series is designed to approximately equalize the RGB response from red-sensitive CCD detectors. This design provides balanced 1:1:1 RGB exposure times with most telescope optical systems, simplifying post-processing and helping reduce the total imaging time required to acquire the different colour channels.

Antlia uses a carefully designed spectral gap between the Green and Red channels to minimize the effects of light pollution while maintaining high transmission of useful frequencies. The filter design is intended to maximize the capture of details from faint galaxies and nebula emissions.

OIII transmission is greater than 95% in both the Blue and Green filters. The overlap between the Blue and Green channels therefore allows the OIII signal to be captured in both channels.

The Red filter is designed to provide maximum transmission of H-alpha and SII emissions, which are particularly important for imaging many emission nebulae.

The Blue channel bandwidth has been narrowed to reduce blue-channel overflow that can produce halos and bloating around bright stars when this channel is overexposed.

A wide spectral gap between the Green and Red filters also blocks the emission line around 589 nm. This design suppresses a significant portion of light pollution from high-pressure sodium and mercury street lamps and contributes to a more natural colour balance.

Antlia uses carefully selected homogeneous optical glass substrates. Advanced optical coating technology and double-sided precision polishing provide consistent optical performance and good parfocal behaviour across the filters.

Dozens of coating layers are deposited on both sides of the glass substrate. Anti-reflection coatings and carefully designed spectral gaps minimize unwanted light scatter and maximize useful signal data in each filter channel, providing a high signal-to-noise ratio.

The cut-off characteristics of the LRGB-V Pro series are specifically designed to minimize halos around brighter stars and reduce star bloat. Particular attention is given to the Blue channel transmission characteristics to address blue star bloating.

All four filters have blackened edges to eliminate internal reflections caused by stray light. The substrate thickness of each filter is maintained within tight tolerances to provide good parfocal performance.

The LRGB-V Pro set is particularly suitable for imaging galaxies, nebulae, star clusters and other deep-sky objects.

Antlia notes that parfocal filters may still require focus adjustments during long imaging sessions. Temperature changes can alter the optical path due to differential contraction between the telescope tube and optical glass elements. The manufacturer therefore recommends checking focus manually or automatically every one to two hours, with more frequent checks when equipment has recently been moved from a warm environment outdoors and has not yet reached thermal equilibrium.

These filters are not recommended for solar observing or solar imaging and are not intended for visual observation.

Technical specifications

• Manufacturer: Antlia
• Series: LRGB-V Pro
• Product: LRGB-V Pro Series filter set
• Format: 50 mm unmounted
• Filter cell: None
• Number of filters: 4
• Filters included: Luminance, Red, Green and Blue
• Luminance filter: Colourless with UV and IR blocking
• Application: Deep-sky astrophotography
• Cameras: Monochrome CCD and CMOS
• Listed suitable sensors: KAF, KAI, Sony IMX, GSENSE and other similar sensors
• RGB exposure balance: 1:1:1 with most telescope optical systems
• OIII transmission: Greater than 95% in Blue and Green filters
• Red filter: Maximum transmission of H-alpha and SII emissions
• Blue and Green filters: Spectral overlap for OIII signal capture in both channels
• Green and Red spectral gap: Designed to block the emission line around 589 nm
• Light pollution reduction: High-pressure sodium and mercury street lamps
• Blue channel: Optimized bandwidth to reduce halos and star bloating
• Coating: Multilayer optical coatings
• Anti-reflection coating: Yes
• Coatings: Applied to both sides of the substrate
• Substrate: High-quality homogeneous optical glass
• Construction: Single non-glued substrate
• Filter edges: Blackened to reduce internal reflections
• Surface quality: 60/40 according to MIL-O-13830
• Transmitted wavefront: Lambda/4 or better
• Parallelism: Less than 30 arcsec
• Parfocality: Substrate thickness maintained within tight tolerances
• Recommended objects: Galaxies, nebulae, star clusters and deep-sky objects
• Not recommended for solar imaging
• Not recommended for solar observation
• Not recommended for visual observation
• Manufacturer warranty: 3 years against delamination