GSO Cassegrain 12" F/12 M-LRC (carbon, truss) OTA (GSO, SKU: CC12A) is a classical Cassegrain telescope with a 304 mm aperture, 3648 mm focal length and f/12 focal ratio. Its long focal length and all-reflective optical system make it particularly suitable for detailed observation and imaging of the Moon, planets, double stars and compact deep-sky objects. The open truss structure with carbon-fibre components helps the optics reach thermal equilibrium, while the fixed primary mirror eliminates image shift during focusing.

Key features

• classical Cassegrain design with a parabolic primary mirror and hyperbolic secondary mirror
• 304 mm aperture and 3648 mm focal length providing a large image scale
• mirrors made of low-thermal-expansion quartz glass
• all-reflective optical path without a corrector plate and without chromatic aberration
• suitable for near-infrared imaging
• open truss structure made of carbon fibre and aluminium
• fixed primary mirror eliminating image shift during focusing
• 33% linear obstruction
• three built-in fans supporting primary mirror cooling
• 3" M-LRC Linear Bearing Crayford focuser with 10:1 fine adjustment
• two Losmandy D standard mounting rails
• multistage internal baffle system reducing stray light

Included accessories

• GSO Cassegrain 12" F/12 M-LRC optical tube assembly
• three built-in fans with battery holder
• 2" to 1.25" adapter
• two 25 mm M117 × 1 extension rings
• one 50 mm M117 × 1 extension ring

Technical specifications

• optical design: classical Cassegrain
• clear aperture: 304 mm (12")
• focal length: 3648 mm
• focal ratio: f/12
• primary mirror: parabolic, made of low-thermal-expansion quartz glass
• secondary mirror: hyperbolic, made of low-thermal-expansion quartz glass
• collimation capability: primary and secondary mirrors
• collimation marker: central marker on the secondary mirror
• linear obstruction: 33%
• illuminated field diameter: 55 mm
• distance between mirrors: 650 mm
• focuser: 3" M-LRC Linear Bearing Crayford, dual-speed 10:1
• eyepiece accessory standard: 2" and 1.25"
• rear tube connection thread: M117 × 1
• distance from the M117 × 1 thread to the focal plane: 350 mm
• mounting rails: two Losmandy D standard rails
• finder shoe: Vixen / Sky-Watcher / TS standard
• tube construction: carbon-fibre and aluminium truss
• internal baffles: multistage knife-edge baffle system
• cooling: three built-in fans with battery holder
• tube length without focuser: 841 mm
• additional length with focuser installed: 133 mm
• external diameter: 440 mm (base), 400 mm (at the end)
• weight: 21 kg
• shipping package dimensions: 106 x 65 x 60 cm, 28 kg

The GSO Cassegrain 12" F/12 M-LRC is intended primarily for use on a stable mount or in an observatory, where its large aperture and long focal length can be fully utilised for observing and imaging small objects requiring a high image scale.