A good 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 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 make 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.