Antlia 2x Barlow Lens for 5Å CaK Solar Filter

This Barlow is not a general-purpose accessory; it is optically matched to the Antlia Solar Discover 5Å CaK assembly. Antlia says it enhances detail and optimizes performance for solar photography, doubling your image scale for finer details like solar plages.

You will need an extension tube if you cannot achieve focus after installing the Barlow lens. If your focuser reaches the end of its outward travel before the image is sharp, one of the optional 50mm or 70mm extension tubes gives the extra back focus Antlia provides them for.

When used with the Antlia Solar Discover 5Å CaK assembly on an 80mm refractor, the Antlia 2x Barlow doubles the image scale. This lets your camera's pixels better sample small features such as plages, which may be too small at the telescope's native focal length. An 80mm refractor is within Antlia's 100mm limit for use without extra light reduction.

Ordering the Barlow pre-installed means you order the Antlia Solar Discover 5Å CaK assembly with the Barlow already installed. Ordering it separately is the option if you already own the CaK filter assembly and wish to add the 2x magnification capability to your existing setup.

No. This Barlow is designed for solar photography with the Antlia Solar Discover 5Å CaK assembly. Antlia does not recommend the Solar Discover 5Å CaK assembly for visual observation; it is primarily used for solar imaging. Use it for imaging only.

Antlia designs this Barlow specifically for the Antlia Solar Discover 5Å CaK assembly and states no other use, so we do not recommend it with other filters such as an H-alpha etalon.