O-III Narrowband Filter SV115 1.25" for Visual - SVBONY

The 1.25-inch O-III filter is useful for large telescopes where the Moon's light can be extremely blinding. It brings out details on darker celestial objects like nebulas. It only allows the doubly ionized oxygen lines between 495.9 nm and 500.7 nm to pass through with an efficiency of 90%.

Features

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

Benefits

This filter is designed to enhance contrast when visually observing gaseous and planetary nebulas under all sky conditions. It provides a high-contrast image even in areas with high light pollution.

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

Usage

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