The Antlia Red+ 36 mm is a long-red enhancement filter from the LRGBR+ Dark series, covering the extended 700–1000 nm band. It is designed for deep-sky astrophotography and enhances the red channel by capturing structures with significant near-infrared emission. The Red+ filter complements the standard R channel and improves detail and color separation in complex emission regions.

Key features

• extended long-red passband from 700–1000 nm for enhanced near-infrared deep-sky imaging
• high peak transmission of approximately 95%
• quartz-glass substrate with extremely low thermal expansion
• out-of-band blocking of ≥OD4.5 (0.005%)
• advanced coatings applied to the edge of the substrate for maximum uniformity
• double-sided fine polishing to ensure parfocality with LRGB and SHO filters
• fully blackened edges (unmounted filter) to suppress stray-light reflections
• compatible and parfocal with Antlia SHO 2.5 nm filters due to identical substrate type
• intended for astrophotography only; not recommended for visual observing

Included items

• Antlia Red+ LRGBR+ Dark series 36 mm (unmounted, blackened edges)

Technical specifications

• filter type: Red+ (extended long-red passband)
• diameter: 36 mm (unmounted)
• transmission range: 700–1000 nm
• peak transmission: approx. 95%
• off-band blocking: ≥OD4.5 (300–1000 nm)
• substrate: quartz glass
• thickness: 2.0 mm ±0.05 mm
• optical finish: double-sided polishing, edge-to-edge coatings
• edge treatment: blackened edges
• not recommended uses: solar observing, visual observing

Warning: NEVER look at the Sun with the Antlia Red+ 36 mm filter. Ignoring this warning can cause permanent eye damage.