Ioptron Green Moon Filter

This Green Moon Filter by iOptron is a simple yet effective accessory designed to enhance lunar and planetary observing through a telescope. By reducing glare and excessive brightness from the Moon and enhancing contrast on features such as albedo markings, it allows for improved visual clarity of subtle surface details.

Key Specs and Features

• Designed for 1.25″ eyepieces with standard filter thread (M28.5 × 0.6) so it screws directly into the barrel of compatible eyepieces.

• Filter size: 31.75 mm (1.25″).

• Transmission: approximately 24% (i.e., reduces incoming light to about a quarter) to reduce brightness and glare.

• Color/Wratten number: Green (#58) which helps increase contrast on lunar surface detail and minimize washed-out bright regions.

• Filter type: Moon/Neutral Density style filter—primarily for visual use rather than imaging.

• Lightweight and easy to install — no additional accessories required beyond a compatible eyepiece.

Use Cases

• Attaching to a telescope eyepiece when observing the Moon to reduce glare and improve contrast between bright and dark regions.

• Use during bright planetary observations (e.g., Venus, bright Mars, or Jupiter) where reducing overall brightness helps reveal finer surface or atmospheric features.

• Ideal for visual astronomy sessions where improved detail and comfort during bright lunar viewing are desired.

• A useful filter for novice to intermediate astronomers seeking a low-cost modification to enhance lunar observing without changing eyepieces.