This Astro-Tech 15mm Paradigm Dual ED eyepiece gives you the outstanding medium power performance of a high-priced eyepiece at a price that will make you wonder why other eyepieces are so high-priced . . .This Astro-Tech 15mm Paradigm Dual ED is an excellent medium power eyepiece for lunar observing, encompassing globular clusters, picking up detail in emission and reflection nebulas, etc. This 15mm focal length is a good choice for filling in the gap between the 25/26mm eyepiece that comes standard with most telescopes and a high power planetary/binary star splitting eyepiece. It is usable with any telescope type, under virtually any seeing conditions - from fair to superb. (Rain, snow, or fog might limit its usefulness, however.)
With a short focal length refractor it is a medium to low power eyepiece well suited to scanning the teeming star clouds of Sagittarius. With the 400mm focal length Astro-Tech AT66ED, for example (a compact 66mm aperture telescope Astronomy magazine said "everyone should own"), its six lens/four group two ED lens optics provide 27x and a field well over four times as wide as the full Moon. This is well suited for observing open clusters such as the Pleiades, and nebulas such as the Lagoon. Both fit nicely into its 2.22° field with the AT66ED, with a framework of black velvet sky around them to set them off.
It is also quite remarkable for medium high magnification observing with long focal length refractors, reflectors, or catadioptric scopes. On an 8" f/10 catadioptric, for example, it yields 133x. This is an excellent magnification for planetary and close-up lunar observing, particularly when the high contrast of the eyepiece (rivaling that of orthoscopics and Brandons) is combined with its excellent color fidelity. Its overall performance makes it a much better choice as a second eyepiece than merely doubling the power of most scopes' so-so standard 25-26mm eyepiece with a Barlow.
The six lens/four group design and two ED (Extra-low Dispersion) glass elements of the 15mm Astro-Tech Paradigm provides all of the optical virtues described at the top of this catalog page - high contrast, a sharp and flat field from edge to edge, excellent color fidelity, and exceptionally low astigmatism and barrel distortion. It has a long usable eye relief of 15mm. Combined with the twist-up eyecup design, the long eye relief makes it a good choice for eyeglass wearers.
This new Astro-Tech 15mm Paradigm Dual ED eyepiece will change your mind about how much truly good optical performance should cost. But be warned. The view through the 15mm Paradigm may tempt you to upgrade all your eyepieces to Paradigms.
