| <Optics> |
| The air-spaced doublet 80mm f/7 achromat objective lens is made by Kubota Optical (Hanamaki-City, Iwate, Japan.). All four surfaces are MgF2 fully coated.
Unlike the conventional photo-visual optical design, which forcibly corrects
all the wavelengths including g-line, this lens is made based on a special
design that focuses on correcting aberrations only at the main wavelengths
in the visual light range. Thanks to this unique design, both chromatic
and spherical aberrations are very well corrected. Furthermore, Kubota Optical's careful and precise polishing technology has resulted in extremely precise
and smooth optical surfaces, yielding surprisingly sharp images that completely
defy the conventional wisdom of short-focus achromats. Even at excessive
magnifications as exceeding 200x, there's little perceptible image deterioration.
When glancing the clear images of planetary surfaces such as Saturn and
Jupiter, everyone will be surprised and wonder, "Is this really a
short-focus achromat?" It's really a premium objective lens that boasts
ultimate performance and truly embodies the "Made-in-Japan pride",
and the main reason why Kasai decided to develop this scope was just because
we are really fascinated by the high potential of this lens. |
| <Focuser> |
| GSO 2" dual-speed Crayford focuser is adopted. Equipped as standard
with a microfocus mechanism with a reduction ratio of 1:10, it provides
an extremely smooth and delicate focusing touch with no backlash, ensuring
that critical focus positions are not missed at high magnifications. Metric/inch
scales on the upper surface of the drawtube. Two fastening screws with
a brass compression ring for 2” eyepiece adapter. A 2"-1.25"
Adapter (w/M48 filter threads) comes standard. The 145mm max. long backfucus
and 80mm long focus travel allow the use of most 2" accessories to
reach the infinity focus easily. A Vixen/GSO/Synta compatible finder bracket
base (finder shoe) comes standard. The 360-degree rotatable function (w/stopper
screw) is especially useful when loaded on a single-fork or a T-shaped
altazimuth mount, keeping the focuser angle horizontally. |
| <Tube / Dewcap / Lens Cell> |
| The main tube and the dewcap are made of lightweight & robust aluminum
alloy with beautiful glossy black finish. All inside the tube are thoroughly
anti-reflection mat painted and well-designed baffles placed to eliminate
the stray lights efficiently, contributing to improve image contrast. The
objective lens cell is made of thick solid aluminum alloy, holding the
delicate lens securely. On the side of the tube, along with the optical
specification, a silver emblem is affixed to ensure that the scope is made
in Japan. |
| <Mounting Bush> |
| On the bottom is equipped with a useful mounting bush with 3 threaded holes (1/4" x 2 + 3/8" x 1), which enables the scope to mount directly onto a camera/video tripod. And, with the use of a dovetail base (optional), the scope can be loaded on various equatorial/altazimuth mounts, too. |
| <Collimation> |
| Precisely machined tube and durable lens cell structures ensure to keep
the optical axis so firmly. Furthermore, as we collimate each unit perfectly
one by one before shipment, there will never be need for the re-collimation
by the users. As long as in the normal use, it can be used completely maintenance-free. |
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