GSO 2.5x Achromatic 3-Element Barlow

GSO 2.5x Achromatic 3-Element Barlow

This Barlow lens has become one of our top-selling products thanks to its excellent performance paired with an affordable price point. The 2.5x magnification is ideal for setups where a standard 2x Barlow falls short, but a 3x magnification might be excessive.

Though marketed as an achromatic 2.5x Barlow, its optical performance is remarkably close to that of a true apochromatic Barlow due to its three-element lens design.

Barlow lenses are used to effectively extend the focal length of your telescope. For example, a 2x Barlow doubles the focal length, which, when divided by the focal length of the eyepiece, results in twice the magnification. This makes Barlows an excellent accessory for amateur astronomers, offering a wider range of magnification options without requiring additional eyepieces. Moreover, since high-magnification eyepieces tend to have shorter eye relief and smaller apertures-making them less comfortable-a Barlow lets you achieve similar magnification using a longer focal length eyepiece that offers a more comfortable viewing experience.

Barlow elements are even integrated into high-end wide-angle eyepiece designs due to their versatile benefits. These lenses are placed between the telescope and the eyepiece and are compatible with 31.7mm (1.25") or 50.8mm (2") eyepiece barrels. This particular model is built for use with a 1.25" barrel