The Explore Scientific 2X Focal Extender (2.0-inch O.D.), accepts both 1.25-inch O.D. and 2.0-inch O.D. format eyepieces and camera adapters. Fully EMD-Coated on all air-to-air lens surfaces, with all lens elements edge-blackened to produce superior contrast, this focal extender adds some real versatility to your telescope accessory line-up. First of all, it allows you to increase the magnification of any eyepiece with the same barrel size that you already own. In other words, 3 eyepieces offer 6 magnification choices with the addition of a focal extender. Secondly, most of the time, lower magnification eyepieces such as the 30mm 82 Degree Series Waterproof Eyepiece have better eye relief than higher power models. When using a focal extender to increase your magnification, you get to enjoy the generous eye relief of the lower power eyepiece, and that’s quite a bonus, especially for eyeglass wearers or for those with fast telescopes who can really push high magnification eyepieces. Remember, we also make 1.25-inch O.D. Focal Extenders in 2X, 3X and 5x models, so there is something for every style of telescope.

Explore Scientific focal extenders feature a telecentric optical design, using multiple precision lens elements to deliver light rays that remain parallel to the optical axis. The result is consistent, true-to-spec magnification—no matter how you configure your eyepiece or camera.

Unlike traditional Barlow lenses, where magnification can vary depending on spacing, Explore Scientific focal extenders provide a stable, predictable performance every time. This design also helps maintain comfortable eye relief and preserves image quality across the field, making them ideal for both visual observing and astrophotography.