Narrowband O-III filter SV115 1.25" for visual use - SVBONY

The 1.25-inch O-III filter is useful for larger telescopes where moonlight can be extremely dazzling. It makes details stand out on darker objects like nebulae. It only allows doubly ionized oxygen lines between 495.9 nm and 500.7 nm to pass through with an efficiency of 90%.

Characteristics

• Size: 1.25 inches (18nm)
• Blocking area: 400-700nm
• Transmission: 90% at 495.9nm and 500.7nm
• FWHM: 18±2nm
• Thickness: 1.85mm

Advantages

This filter is designed to improve contrast when visually observing gaseous and planetary nebulae in all sky conditions. It allows for high-contrast images even in areas with strong light pollution.

The filter is made from high-quality glass with dichroic interference and anti-reflection coatings, making it useful not only in light-polluted sites but also to increase contrast in dark sites.

Usage

This filter can be used with all 1.25-inch eyepieces. It is designed to block almost all other visible wavelengths, optimizing the view of nebulae.