Ideal for both visual observation and astrophotography, the Explore Scientific ED 140mm f/6.5 Air-Spaced APO Triplet CF Refractor
is ideal for lunar, planetary, and deep-sky viewing while still being
highly portable. Using Ohara FPL-53 extra low-dispersion (ED) glass in
an apochromatic air-spaced triplet lens configuration, with fully
multi-coated optics, produces images that are clear and bright without
fringing, halos, or distortion across the entire field of view, with
true color rendition and high contrast. The fast focal ratio, when
combined with the optical performance, makes this an ideal astrograph to
capture images with accurate colors and limited distortion across the
entire field of view.
To handle large imaging rigs and
accessories, Explore Scientific outfitted the OTA with a heavy-duty
focuser to carry imaging gear and accessories. Using a traditional
rack-and-pinion mechanism makes it more solid and sturdy than comparable
Crayfords, while the large 3" hexagonal drawtube is stronger and less
prone to flexing than conventional round tubes. When put together, the
focuser, by itself, has an impressive payload capacity of 10 pounds —
allowing it to comfortably carry the heaviest of astrophotography rigs
with ease. A two-speed system allows for fast coarse, then precision
fine focusing to ensure the most sharp and crisp views possible.
Offered
here as an OTA-only option for those with reliable support systems, the
carbon fiber tube weighs just 21 pounds, and can be carried by a wide
array of mounts. A cradle ring set is included, with an integrated
handle for safer setup and breakdown. A Vixen-style dovetail plate makes
it compatible with a wide array of alt-azimuth, equatorial, and GoTo
mounts. The cradle ring assembly also allows the orientation and
position of the OTA relative to the mount to be adjusted for better
balance and to avoid interference with equipment or mount. The OTA's
carbon fiber construction also resists the expansion and contraction
common in metal tubes when moving between extreme temperatures, which
can cause the internal lens elements to move out of alignment over time,
affecting the scope's ability to achieve sharp focus and causing
fringing and halos.
Whether you want an OTA for fast observation
without compromising image quality, or a fast OTA that produces bright
and clear images of the moon, planets, galaxies, nebulae, or star
clusters, this Explore Scientific optical tube assembly is ideal.