Baader Planetarium O-III Nebula Telescope Filter

This filter is specifically designed for diffuse and planetary nebulae. By isolating the doubly ionized oxygen lines, it significantly boosts the contrast of these gas clouds against the dark background of space, often revealing structural details that are invisible without it.

No. Because the substrate is precision-polished and flat, it maintains pinpoint star sharpness even when you are using high magnifications. It is engineered to avoid the double images or color shifts sometimes found in lower-quality filters.

The narrow 8.2nm bandpass is the key to this filter's performance. It is tight enough to block out unwanted light pollution and airglow, allowing only the specific light from ionized oxygen to pass through, which results in a much higher-contrast view of your target.

It is excellent for both. The advanced DWDM plasma-assisted coatings are durable and designed to maintain high optical quality, making it a reliable tool for serious deep-sky imaging as well as visual observing.

This filter fits standard 2-inch telescope eyepieces and accessories. Before purchasing, ensure your telescope's focuser or filter wheel is compatible with the 2-inch format.