| This 20mm Vixen Lanthanum eyepiece is a medium long focal length eyepiece with exceptionally long eye relief for eyeglass use. It uses six optical elements in four groups to achieve an eyeglass-friendly 20mm eye relief that is nearly twice as long as similar focal length eyepieces of comparable optical quality, such as a Plössl. The 20mm Vixen eyepiece is usable with any telescope type, under virtually any seeing conditions – from fair to superb. With short focal length refractors, it’s a low power/wide field eyepiece. It is also excellent for medium magnification lunar, planetary, and globular cluster observing with longer focal length refractors and reflectors, or long focal length catadioptric scopes. The optical performance and width of field of the 20mm Vixen are comparable to other quality eyepieces in its price range. There is a slight loss of contrast when compared to simpler eyepiece designs, such as a four-element Plössl, due to the additional optical elements needed to achieve the long eye relief of this Vixen. The loss is minimal though, and this 20mm Vixen would still have the benefit of much longer eye relief (particularly at a price half that of other 20mm eye relief eyepieces in this focal length range). |
Email page link to a friend
