High-quality 3-element, achromatic 2xL Vixen DeLuxe Barlow lens in 1.25 "(31.7mm) standard. Vixen Barlow 2x DeLuxe in a solid metal housing is characterized by a high transmission of light and generates a very sharp image. In contrast to cheaper counterparts, it has very little chromatic aberration. It has green-blue FMC anti-reflective coatings (Fully Multi-Coated, all optical surfaces coated with anti-reflective layers). It works great in planetary observations, goes to competitions with apochromatic Barlows such as Celestron Ultima APO 2x. The basic benefit of using Barlow's lenses is that they allow you to limit the number of glasses while providing a large span of available magnifications. For example, having 2 glasses with 30 and 15mm focal lengths, we use the Barlow lens to get two additional magnification corresponding to 10 and 5mm focal length spectacles. In addition, the Barlow lens does not change the eye- shadow offset of the eyepiece ( eye relief ), allows you to focus farther away from the tube (when you have a problem with sharpening the image) and allow you to extend the focal length twice while taking pictures of the sky in the lens focus.
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