Product features:
- Appature 16" / 406 mm
- Focal Length 3250 mm
- Focal ratio f/8
- Choice of field flatteners and focal reducers.
- Carbon truss tube with 2 Losmandy Level
   dovetail bars
- 99% dielectric high-reflectivty coating on main-
  and secondary mirror
- Big corrected flat field without need for
   additional correctors
- 3" MONORAIL Focuser with better stability
- Redesigned back plate, decoupling of the focuser
   from the telescope with seperate collimation.
Astrofox has optimized this 16" RC especiall for astro photography.
The OTA comes with carbon trusses having a thermal expansion of nearly 0. The OTA weight is 37 kgs and it has a Losmandy-style dovetail rail on both sides.

Our 16" f/8 RC Astrograph illuminates a max- field diameter of approx. 70 mm.
Without corrector, 35 mm are possible. In the latter configunartion, 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 the focus:
The 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 127mm.
The Carbon Fiber Truss Tube Design:

Lightweight yet strong carbon fiber 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 regardles

  The 3" M-LRN Monorail Focuser:

The 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 evely across the rail´s surface.

Technical details of the focuser:
- Travel: ca. 80mm
- Free aperture: 68mm
- 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
Optical Highlights:
The hyperbolic primary and hyperbolic secondary are made from low expansion 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.

Cooling Fans:
The RC telescope 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 separately).

A Fixed Primary Eliminates Image Shift:

Schmidt-Cassegrain,m EHD, ACF... & Mak-Cassegrain telescopes achieve focus by moving the primary mirror back and forth inside the optical tube assembly, and this movement can cause image shift. While manufacturers have done a pretty good job of minimizing image shift 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:
This is also the advantage of RC telescopes against Celestron EHC or Meade ACF telescopes. These telescopes needs a lens corrector wich 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 the GSO400 RC *Ritchey Chrétien Astrographs for astrophotography:

The GSO400 Astrograph is a real Ritchey-Chrétien 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.
   GSO400 EUR  6500,-  excl. VAT and shipping