Crave large aperture? The reflector design reins supreme as the king
of large aperture. The most popular reflector design configurations are
the classic Newtonian and the SCT. The SCT is an exotic form of
reflector using mirrors and a lens, sometimes called a mirror-lens, or
catadioptric. If you can imagine for a moment the classical Newtonian
reflector as the full-size SUV of astronomical optical systems, then
the SCT would be its more petite, luxury SUV cousin. The SCT is more
challenging to fabricate, thus more expensive, but it has several
advantages that off set the extra cost in the minds of a significant
number of amateur astronomers. The primary advantage is compact size
compared to Newtonian reflectors and refractors. It takes up less space
and is easier to handle and transport. It is also known for excellent
optical quality. The 8" SCT will provide razor sharp, high
resolution images suitable for passionate lifelong engagement in sky
exploration. The amateur astronomer also benefits from computerized
object location and tracking of over 30,000 astronomical objects. All
things considered, the 8" SCT on an Sky-Watcher EQ5 PRO will strike the perfect
balance for many amateur astronomers between cost, aperture, and ease
of use.
Observing with the 8" SCT EQ5 PRO:
An 8"
(203mm) instrument is generally regarded as the entry point for serious
astronomical observation of deep-space phenomenon. Even within our
solar system, the 8" SCT optics will reveal fine detail all but
impossible to discern with smaller aperture telescopes. View with
terrestrial-like clarity the large contiguous lunar craters Ptolemaeus,
Alphonsus, and Arzachel with their jagged crater walls, fine fault
lines, and craterlets perhaps as small as 20-miles across. Saturn's
awesome ring structure is revealed in amazing detail including
Cassini's Division. Jupiter's cloud bands show very discernable dusky
colors and appear as billowing bands with swirling festoons. In the
wintertime sky, the gaseous, glowing Lagoon Nebula, fire red in
astrophotographs, and the smaller Trifid Nebula, beautiful blue and
light red in astrophotographs, are examples of prominent emission
nebula revealing bright cores with billowing cloud-like inner structure
and delicate, wispy detail in their outer extensions. The brilliant
globular cluster M13 in Constellation Hercules reveals perfectly
resolved individually discreet star points down into the central core.
The beautiful Rosette Nebula in Monoceros, M33 the spiral galaxy in
Triangulum, M17 the Omega Nebula in Constellation Sagittarius are just
a few of the many deep-sky objects available to amateur astronomers in
a 8" SCT. The 8" SCT is also perfectly adapted for viewing and
photographing faint, distant galaxies like the Sombrero (M104), the
Pinwheel (M101), and Spiral Galaxy (M81). The 8" SCT on an Sky-Watcher EQ5 PRO database
includes over 30,000 fascinating objects that are ready to be explored
with a few touches of the SynScan's computer keypad.
SCT Design Advantages:
The
Schmidt-Cassegrain optical system folds the light path back on top of
itself, thus producing a powerful long focal length instrument in a
compact optical tube. A shorter tube means less bulk and weight to lift
and transport. The closed optical tube also serves to keep the optics
cleaner. These are prime design advantages of an SCT.
SCT optical fabrication a global standard of excellence:
Schmidt-Cassegrain optics are hand-figured by skilled opticians and
fabricated to the highest standards of optical smoothness and
correction, ensuring diffraction-limited premium optical performance
that is second to none worldwide.
On each spherical shaped primary mirror of low thermal expansion
glass, aluminum is vacuum deposited to the front surface and then over
coated with hard quartz (SiO4). Additional layers of Titanium Dioxide (TiO2) and (SiO4)
are then applied. The white-water glass aspheric shaped "Schmidt"
corrector lens is multi-coated with Metallic High-Transmission
Coatings, MHC, (Magnesium Fluorite, MgF2, and Hafnium, HfO2) to insure
maximum light through-put approaching 97%. The system's overall light
transmission from 400 to 750nm approaches 84%. A secondary mirror is
attached to the center of the corrector plate. This smaller mirror is
fabricated similarly to the primary mirror. Internal light baffles and
blackened interiors help prevent stray, unfocused light from reaching
the focal plane and reducing contrast.
Optical focus is achieved by micrometric mechanical movement of the
primary mirror forward or backward on an internal "slider" shaft. The
primary mirror is perforated in the middle and the observer views at
the focal plane which is positioned just outside the back of the
optical tube.
The optical tube material is rolled steel, powder coated reflective
gloss black with gold fleck accent. The front and back cells are cast
aluminum painted black.
Quality Accessories: Included are two high quality
1.25" eyepieces (Super Plossl 32mm and 10mm), 8x50 optical Viewfinder
with bracket, Visual Back 1.25" and 1.25" Mirror Diagonal.
