| 8" f/6 Newtonian OTA fully optimized for planetary observations. Equipped
with special features to bring out the highest potential of Newtonian system,
such as very small central obstruction, thin vane spiders, 9-point flotation
primary mirror cell, baffle rings inside the tube, long nose part working
as a dewcap, extra large deep hollow on the other side of the focuser to
eliminate the reflection lights, the ventilation holes in front of the
primary mirror housing to suck in air from outside to relieve the tube
current - all those features contribute to the extremely sharp, high-definition
& high-contrast visual images of planets. Rigid GFRP (Glass-Fiber Reinforced
Plastic) tube is lightweight enough to load onto mass-market small- to
middle-class equatorial mounts. Comes with a low-profile 2" micro
focuser. A large opening equipped on the side in front of the primary mirror
for easy maintenance of the optical surface. An electric ventilator at
the bottom of the primary mirror cell to quicken the thermal acclimation.
Since this unique scope was on sale in 2002, it has attracted many Japanese
serious planetary observers for years. Now it's your turn to enjoy crisp
& clear planetary images through this custom-made special scope designed
and manufactured with the utmost care by Kasai. |
| <Development Concept> |
| Primarily, Newtonian telescopes have very high potential for good visual
images. However, not a few mass-market Newtonians are optimized for prime-focus
photos, as with huge secondary mirrors, too thick spiders, etc., largely
spoiling the original good image quality. Worrying this slanted situation,
Kasai dared to make a special Newtonian embodying many factors to bring
out the highest potential and to yield the very best images - it's NERO-200N. |
| <Optics & Cells> |
| Precision GSO primary mirror is installed. High homogeneity BK7 optical
glass material. Each primary mirror is individually tested with ZYGO interferometer,
assuring high quality as within 1/6-lambda on peak-to-valley wavefront,
and 1/30-lambda RMS. The certificate with interferometric photo is provided.
93% enhanced coating brings clear images with little scattered light. The
center mark is dotted to ease the collimation. The 9-point flotation primary
mirror cell is supplied by Orion-Optics UK, preventing the deforming of
the mirror surface and bringing out the best optical performance. By cutting
off the excessive parts of the mirror fixing nails, image deterioration
from uneven obstructions around the mirror is reduced. Spiders and secondary
mirror cell are supplied by RP-Astro in Italy. 20.5% extra small central
obstruction and 1mm thin 4-vane spiders contribute very high definition,
exerting top performance in observing faint figures on planets. |
| <High-Contrast Tube Design> |
| The best characteristic of NERO-200N exists in the unique tube design.
To realize the boldly deformed tube shape, flexibly-moldable and very sturdy
GFRP (Glass-Fiber Reinforced Plastic) material is used. The top end of
the tube is rolled inside like a baffle, and the nose part is long enough
to work as a dewcap to eliminate the stray lights. The counter side of
the focuser is shaped like a big & deep hollow to eliminate the reflection
lights to the field of view dramatically. The tube diameter near the primary
cell is about 10% larger than the front part, and a baffle ring is inserted
in between. These features help to wall off the reflection stray lights
from the primary mirror. Those thorough special features bring extremely
high image contrast, as it shows very clear images without any color deterioration
even in the daytime terrestrial observation with high power, and as it
shows very dark background as the edge of the field can't be detected even
when seeing a very bright planet. Multiple oval ventilation holes around
the joint part of the tube and an electric ventilator on the back of the
primary mirror help to vacuum the warm air current around the primary mirror,
preventing the tube current from the beginning. A large opening (with a
dustcover) is situated on the side in front of the primary mirror for easy
access to the mirror surface, which can be cleaned easily and kept in good
condition anytime. |
| <Focuser> |
| A precision low-profile micro focuser with dual drawtubes is installed.
In spite of the total height of the focuser is only 47mm, the total focus
travel is such long as 70mm: 26mm travel by the outer tube + 44mm by the
inner. The outer tube is operated with butter-smooth 1:10 dual-speed crayford
focusing mechanism, and the inner tube is to be pushed-and-pulled smoothly.
The 2" eyepiece adapter employs compression ring stopper system. A
1.5mm-height extra low-profile 1.25" eyepiece adapter (M48 filter
threaded) is included. A finderscope bracket base is placed above the focuser,
accepting many brands' brackets like Vixen, Synta, GSO, etc. |
| <Tube Rings & Plate> |
| Solid tube rings and Vixen-compatible long dovetailed plate is standard, fitting various mass-market mounts directly. |
| <General Aptitude> |
| NERO-200N is a "purified" Newtonian only for obtaining the very
best visual images. Meeting all 3 important conditions (sharpness, contrast
and definition), it's an ideal scope for lunar and planetary observations.
The lightweight tube loadable onto a small mounting is also an advantage.
Strongly recommended to those who longing for a non-compromised highest
quality visual telescope. |
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