GSO Ritchey-Chretien Ritchey-Chrétien RC 254/2000 carbon-fibre OTA

GSO RC astrograph:

This is a newly developed telescope from GSO, for the first time at a more affordable price, and is especially suitable for astrophotography as it is a pure reflection system and so has no chromatic aberration. This is due to the use of two mirrors - a hyperbolic primary mirror and a convex hyperbolic secondary mirror. The image is coma-free and has a wide field of view. The open system and quartz mirror mean that RC OTAs cool quickly and there is virtually no problem with dew. This ingenious system even allows infrared photography.

The monorail focuser carries the weight on a rail, in contrast to Crayford focusers where it is carried on ball bearings, and guarantees shift-free adjustment and setting up. It is suitable for a large range of eyepieces thanks to the 3" connection and 2" reducing adapter.

The advantages in a nutshell:

• ideal for astrophotography
• no chromatic aberration
• open system

• Specifications:

  Optics
  Type	Reflector
  Type of build	Ritchey-Chretien
  Aperture (mm)	254
  Focal length (mm)	2000
  Aperture ratio	7,9
  Resolving capacity	0,45
  Limit value (mag)	13,8
  Light gathering capacity	1320
  Max. useful magnification	508
  Tube weight (kg)	14,6
  Tube material	Carbon
  tube diameter (mm)	294
  Tube length (mm)	735
  Reflector
  Main mirror´s construction	hyperbolic
  Secondary mirror diameter (mm)	112
  reflectivity	99
  Eyepiece holder
  Type of build	Crayford
  Connection ( to eyepiece)	3
  Gear reduction	1:10 Fine movement
  Rotating	yes
  Mount
  Mounting type	no mount
  Type of build	OTA
  GoTo control	no
  Tracking	no
  Included accessories
  Prism rail	Losmandy-Style
  Area of application
  Moon & Planets	yes
  Nebulae & galaxies	yes
  Nature observation	yes
  Astrophotography	yes
  Sun	not recommended (Only with appropriate Sun filter)
  recommended for
  Beginners	no
  Advanced	yes
  Experienced amateurs	yes