XCel ED eyepieces

More Information  · Recommended Accessories Price $67.95 List Price $102.95 Field of view 55° Eye Relief 20mm Focal Length 12.5mm Number of optical elements 6 Barrel Size 1.25" Warranty 2 years Telescope Eyepiece Formula To calculate the magnification and approximate actual field of view of this eyepiece on your telescope, enter the focal length of your telescope below and press the "Calculate" button. mm

With short focal length refractors it is a low power eyepiece. With the 500mm focal length Celestron Firstscope 102AZ, for example, its five-layer multicoated ED (extra-low dispersion) glass six-element optics provide 40x and a field almost three times as wide as the Moon. This is well suited for observing open clusters such as the Pleiades and large nebulas such as the Lagoon. Both will fit nicely into its 1.38 degree field when used with the Firstscope 102AZ, with a framework of black sky around the objects to set them off.

It is also quite good for medium high magnification observing with long focal length refractors, reflectors, or catadioptric scopes. On a 7" Maksutov, for example, it yields 212x. This is an excellent magnification for planetary and close-up lunar observing, particularly when the high contrast of the eyepiece is combined with the high contrast of the Maksutov. Its performance makes it a much better choice as a second eyepiece than merely doubling the power of most scopes’ standard 25-26mm eyepiece with a Barlow.

A soft rubber eyecup shields the eye from ambient light and rolls down for more comfortable eyeglass use. A knurled rubber ring on the barrel provides a secure grip when changing eyepieces in cold weather.