Antlia planetary filter Methane (CH4)

Antlia CH₄ filter (Methane)

The Antlia CH₄ (Methane) filter is a specialized filter designed for near-infrared planetary imaging, centered at 889 nm. It reveals fine details in the atmospheres of planets such as Jupiter, Saturn, Mars, and other methane-rich celestial bodies. It is intended exclusively for photographic use and not for visual observation.

Key features

• Transmission centered on 889nm with 20nm bandwidth
• Average transmission over 80% in the center
• OD4 suppression of unwanted wavelengths from 200 nm to 1050 nm
• Schott optical substrate, one-piece, unglued
• Double-sided optical polishing for a λ/4 surface finish
• Surface quality: 60/40 (MIL-O-13830 standard)
• Parallelism less than 30 arcsec
• Multilayer anti-reflective coating on both sides

Ideal applications

• Planetary imaging of Jupiter to highlight methane bands
• Photographic observation of the Martian polar caps
• Study of the atmospheres of Saturn and other gas giants

Available formats

• 1.25″ Mount (M28.5×0.6)

Filter design

• Ultra-fine cell to minimize vignetting
• Durable black anodized finish
• Permanent laser engraving (does not fade)

Important warnings

• The CH₄ filter is not designed for visual observation.
• DO NOT use for solar imaging without an energy-rejection filter.
• Risk of damage to telescope, filter and sensor if used without appropriate protection from the sun.

User Notes

• Recommended for use with long exposures and large apertures
• Requires a sensitive near-infrared camera
• Invisible to the human eye (beyond 700 nm)