The GSO 10" f/4 Carbon Photo-Newton optical tube assembly is an astrograph designed for deep-sky astrophotography, based on a Newtonian reflector with a parabolic primary mirror of 250 mm diameter. The full-length carbon fiber tube provides high mechanical rigidity and excellent focus stability under temperature variations, which is particularly important during long imaging sessions.

Key features

• 250 mm (10") aperture and f/4 focal ratio
• full-length carbon fiber tube with high thermal stability
• parabolic primary mirror manufactured by GSO (Taiwan)
• rack-and-pinion focuser designed for heavy imaging equipment, compatible with ZWO EAF motor focuser
• active primary mirror cooling – 3 fans
• collimatable primary and secondary mirror cells
• monolithic CNC-machined secondary mirror spider
• internal baffles to reduce stray light
• two Losmandy-type mounting rails to increase rigidity and facilitate balancing

Items included

• GSO 10" f/4 Carbon Photo-Newton optical tube assembly
• tube rings
• two Losmandy-type mounting rails

Technical specifications

• manufacturer: GSO (Taiwan)
• SKU: GSN800C
• optical design: Newtonian reflector (parabolic)
• primary mirror diameter: 250 mm
• focal length: 1000 mm
• focal ratio: f/4
• intended use: astrophotography
• tube: full-length, carbon fiber
• tube length: 88 cm
• focuser: rack-and-pinion with microfocuser, compatible with ZWO EAF
• focuser outer diameter: 83 mm / 3.25"
• external male thread at focuser end: M82
• internal thread at focuser end: M76
• threaded reducer: M76 (male) to M72 (male), screw-on type
• eyepiece reducer: 3" to 2"
• accessory compatibility: 2" / 1.25" (via reducer)
• primary mirror cooling: active, 3 fans
• collimation: primary and secondary mirrors – adjustable
• secondary mirror spider: monolithic CNC construction
• mounting rails: 2 × Losmandy
• optical tube weight (without rings): 10.0 kg
• weight with tube rings: 11.0 kg
• weight with tube rings and mounting rails: 12.5 kg