TS-Optics 12 inch f/8 Ritchey-Chrétien Astrograph on Skywatcher EQ8 GoTo Mount The TS 12" f/8 Ritchey Chretien Astrograph is a dream
telescope for astrophotography. The telescope is fitted with a stable
Carbon Fibre Truss Tube and a precise 3" dual speed Monorail focuser.
TS 12" f/8 Ritchey Chretien Truss Tube Astrograph is a true RC
telescope and will give you spectacular photo results also with large
format camera sensors.
The telescope is perfect for small observatories and will be carried from mounts in the EQ8 class.
Optimized for astrophotography
- Aperture 12" / 304 mm
- Focal Length 2432 mm
- Focal Ratio f/8
- Carbon truss tube with 2 Losmandy level dovetail bars
- 99 % dielectric high-reflectivity coating on main and secondary mirror
- Big corrected flat field without need for additional correctors
- 3" Monorail Focuser with better stability
OTA comes with carbon trusses having a thermal expansion of nearly
zero. The OTA weight is 24 kg and it has a Losmandy style dovetail rail
on both sides.
The 12" f/8 RC Astrograph
max. field diameter of approx. 60 mm. Without corrector, 35 mm are
possible. In the latter configuration, you have a pure mirror system
without any lenses. You don´t need an IR cut filter and can use the full
spectrum with a suitable CCD camera.
How to find focus
TS RC has a generous back focus allowing to attach many accessories
like off-axis guiders, filterwheels and much more. The distance from the
2" connection of the focuser to the focus point is 127 mm.
the perfect focus position, we suggest the GSRCV1172 and GSRCV1175
extension rings. The position of the rings is between focuser and tube
backside. So you always have a good position of the draw tube.
The Carbon Fibre Truss Tube Design
yet strong carbon fibre truss tubes have low thermal expansion
characteristics. Shifts in focus due to temperature changes are
minimized because of this design. The trusses are also designed to flex
equally, keeping the optics in collimation.
The 3" M-LRN Monorail Focuser
3" Monorail focuser is a further development of the Crayford design.
The load is not carried by four (often underdimensioned) ball bearings,
but on a stainless steel track on the base, thus preventing tilting and
bending even under high loads. It is countered by a big knurled screw
that centers the inner tube exactly to the rail. The load is distributed
evenly across the rail´s surface. Technical details of the focuser:
- Travel: ca. 80 mm
- Clear aperture: 68 mm
- Guidance: by massive and fixed steel rail
- 1:10 transmission for precise focusing
- 360° Rotation
- Adaption to 2" and (when screwed off) female M68 thread, directly fitting to TS 2.5" off axis guider
hyperbolic primary and hyperbolic secondary are made from low expansion
fused quartz, and finished with a scratch-resistant highly reflective
99 % dielectric coating for great contrast. The primary mirror is fixed
in place in a metal mirror cell, and the secondary resides in a metal
housing that can be collimated. The secondary mirror has a center mark
for easy and accurate collimation.
RC telescopes has three small cooling fans in the rear cell that help
create an ambient temperature within your telescope for more stable
viewing and less fluctuation in focus. The fans are powered by an
external battery pack. This battery holder accepts 8 AA batteries (sold
A Fixed Primary Eliminates Image Shift
EHD, ACF, and Mak-Cassegrain telescopes achieve focus by moving the
primary mirror back and forth inside the optical tube assembly, and this
movement can cause image shifts. While manufacturers have done a pretty
good job of minimizing image shifts on their telescopes, a moveable
mirror makes it almost impossible to eliminate it completely. The
Ritchey Chretien has a primary that is fixed in place, removing the
possibility of image shift and also the job of collimating the primary.
Why the RC Telescope is better than Schmidt-Cassegrain telescopes with correctors
is also the advantage of RC telescopes against Celestron EHD or Meade
ACF telescopes. These telescopes need a lens corrector which is
integrated in the optical system. The RC is a true reflection system
without lens corrector and with a really bright image.
The optical advantages of TS RC Ritchey Chretien Astrographs for astrophotography
TS Astrograph is a real Ritchey Chretien reflector telescope. Contrary
to Maksutovs or Schmidt-Cassegrains which have spherical mirrors and
need image correctors, and contrary to Newtonians that need coma
correctors, the RC system is a well corrected photographical instrument
that uses only mirrors (no false colour!) and does not require any
corrector with many cameras.Delivery contents
- 12" f/8 RC Astrograph
- 3" Focuser with 1:10 micro transmission
- Reduction to 2" and to 1.25"
- 2x Dovetails - Losmandy level
- EQ8 GoTo Mount with 2x 10 kg counterweights
- Berlebach Tripod PLANET
The TS 12" f/8 Ritchey-Chrétien Astrograph and the massive Skywatcher EQ8 Goto Mount is a dream telescope for astrophotography.