This Astro-Tech 25mm Paradigm Dual ED is an excellent medium to low
power eyepiece for encompassing open clusters, picking up detail in
emission and reflection nebulas while still viewing them in their
entirety, etc. This high quality 25mm focal length optical gem will
visibly upgrade the performance of the usually only so-so 25/26mm
eyepiece that typically comes standard with most telescopes. It is also a
good choice to complement the 40mm eyepiece provided with some go-to
Schmidt-Cassegrains. The 25mm Astro-Tech Paradigm 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 low power eyepiece well suited
to scanning the crowded star clouds of Sagittarius, observing galaxy
clusters, framing the more compact emission nebulas with the black of
space, observing the nebulosity around the Pleiades, etc. With the 430mm
focal length f/6 Astro-Tech AT72ED, its six lens/four group two ED lens
optics provide a magnification of 17x, a field nearly seven times as
wide as the full Moon, and a 4.16mm exit pupil that is ideal for rich
field observing.
The 25mm Astro-Tech Paradigm is also a good
choice for medium power observing with long focal length refractors,
reflectors, and catadioptric scopes. On an 8" f/10 catadioptric, for
example, it yields 80x, with a 0.75° field that is half again as wide as
the full Moon. This is a very useful magnification for observing
compact planetary nebulas and globular clusters, as well as lunar
observing. Its high contrast makes observing small features along the
lunar terminator a nightly delight as the terminator creeps across the
face of the Moon.
The six lens/four group design and two ED
(Extra-low Dispersion) glass elements of the 25mm 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 usable eye relief of 15mm. Combined with the
twist-up eyecup design, the good eye relief makes it a sensible choice
for eyeglass wearers.
This new Astro-Tech 25mm Paradigm Dual ED
eyepiece will upgrade your scope’s starter eyepiece, bringing new life
to your nightly views of the heavens. The 25mm Paradigm will change your
mind about just how good low power viewing with a telescope can be,
with truly high-end optical performance at a not very high-end price.
